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Keywords = pre-existing antibodies

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12 pages, 3161 KiB  
Article
Evaluation of Poxvirus-Specific Antibody Response in Monkey Poxvirus-Negative and -Positive Cohorts
by Nannan Jia, Lin Ai, Yunping Ma, Chen Hua, Qi Shen, Chen Wang, Teng Li, Yingdan Wang, Yunyi Li, Yin Yang, Chi Zhou, Min Chen, Huanyu Wu, Xin Chen, Lu Lu, Yanqiu Zhou, Jinghe Huang and Fan Wu
Vaccines 2025, 13(8), 795; https://doi.org/10.3390/vaccines13080795 - 27 Jul 2025
Viewed by 344
Abstract
Objectives: Understanding the antibody response in monkeypox virus (MPXV)-infected and uninfected individuals is essential for developing next-generation MPXV vaccines. This study aimed to characterize neutralizing antibody (NAb) and antibody-dependent cellular cytotoxicity (ADCC) responses in both groups, providing insights into immune protection and vaccine [...] Read more.
Objectives: Understanding the antibody response in monkeypox virus (MPXV)-infected and uninfected individuals is essential for developing next-generation MPXV vaccines. This study aimed to characterize neutralizing antibody (NAb) and antibody-dependent cellular cytotoxicity (ADCC) responses in both groups, providing insights into immune protection and vaccine design. Methods: A recombinant vaccinia Tian Tan (VTT) virus was utilized to develop high-throughput luciferase-reporter-based neutralization and ADCC assays. These assays were applied to evaluate the presence and levels of poxvirus-specific antibodies in MPXV-infected and uninfected individuals, including those vaccinated with vaccinia-based vaccines. Results: Poxvirus-specific NAbs were detected in MPXV-negative individuals with prior vaccinia vaccination. However, MSM individuals exhibited significantly lower pre-existing NAb levels than non-MSM individuals, potentially contributing to their higher susceptibility to MPXV infection. In individuals with mild MPXV infection, robust NAb and ADCC responses were observed, regardless of vaccination status. Additionally, HIV-positive individuals demonstrated comparable antibody responses following MPXV infection. Conclusions: These findings highlight the potential role of pre-existing NAbs in MPXV susceptibility and the strong immune response elicited by mild MPXV infection. Further research is needed to determine whether MPXV-specific antibodies mitigate disease progression, which could inform the development of effective MPXV vaccines. Full article
(This article belongs to the Section Human Papillomavirus Vaccines)
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13 pages, 1542 KiB  
Case Report
Reclassification of Seronegative Rheumatoid Arthritis as Anti-PL-12 Antisynthetase Syndrome with Interstitial Lung Disease and Joint Involvement–Case Report
by Diana Elena Cosău, Alexandru Dan Costache, Irina Iuliana Costache Enache, Ionela Lăcrămioara Șerban, Luiza Andreea Petrariu, Cristina Pomîrleanu, Mara Russu, Vladia Lăpuște and Codrina Ancuța
Reports 2025, 8(3), 123; https://doi.org/10.3390/reports8030123 - 26 Jul 2025
Viewed by 372
Abstract
Background and Clinical Significance: Antisynthetase syndrome (ASyS) is a rare autoimmune entity defined by the presence of anti-aminoacyl-t ribonucleic acid (RNA) synthetase autoantibodies and classically associated with a triad of interstitial lung disease (ILD), inflammatory myopathy, and arthritis. Additional clinical features may include [...] Read more.
Background and Clinical Significance: Antisynthetase syndrome (ASyS) is a rare autoimmune entity defined by the presence of anti-aminoacyl-t ribonucleic acid (RNA) synthetase autoantibodies and classically associated with a triad of interstitial lung disease (ILD), inflammatory myopathy, and arthritis. Additional clinical features may include Raynaud’s phenomenon and “mechanic’s hands”. Among antisynthetase antibodies, anti-PL-12 is notably associated with predominant or isolated ILD and may occur in the absence of clinically evident myositis, thereby complicating timely diagnosis. Case Presentation: We are presenting a 45-year-old non-smoking female patient with a prior diagnosis of seronegative rheumatoid arthritis (RA) who developed progressive dyspnea, dry cough, and sicca symptoms. High-resolution computed tomography revealed a nonspecific interstitial pneumonia (NSIP) pattern. Despite normal creatine kinase and lactate dehydrogenase levels, serological work-up revealed positive anti-PL-12 and anti-Ro52 antibodies, supporting a diagnosis of antisynthetase syndrome without myositis, fulfilling the diagnostic criteria for ASyS per Connors and Solomon. Treatment with corticosteroids and cyclophosphamide induced clinical and functional respiratory improvement, while azathioprine was initiated for maintenance. Conclusions: This case underscores the clinical heterogeneity of antisynthetase syndrome and highlights the diagnostic challenge posed by anti-PL-12–associated ILD in the absence of myositis. Importantly, it demonstrates that in patients with pre-existing rheumatologic diagnoses, the emergence of atypical pulmonary manifestations warrants repeat serologic evaluation to assess ASyS and other autoimmune conditions. Early diagnosis and immunosuppressive treatment are essential to optimize outcomes. Full article
(This article belongs to the Section Critical Care/Emergency Medicine/Pulmonary)
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12 pages, 1316 KiB  
Article
Retinal Epithelial Neutralization Assay Optimizes AAV Serotype Selection for Ocular Gene Therapy
by Yao Li, Yujia Chen, Nan Huo, Zuyuan Jia, He Huang, Zhenghao Zhao, Shipo Wu and Lihua Hou
Viruses 2025, 17(7), 988; https://doi.org/10.3390/v17070988 - 15 Jul 2025
Viewed by 373
Abstract
Adeno-associated virus (AAV) vectors face a critical translational challenge in ocular gene therapy due to pre-existing neutralizing antibodies (NAbs) whose seroprevalence limits patient eligibility. Standard NAb detection using non-ocular cell models (Human Embryonic Kidney 293T) may inadequately predict retinal transduction inhibition due to [...] Read more.
Adeno-associated virus (AAV) vectors face a critical translational challenge in ocular gene therapy due to pre-existing neutralizing antibodies (NAbs) whose seroprevalence limits patient eligibility. Standard NAb detection using non-ocular cell models (Human Embryonic Kidney 293T) may inadequately predict retinal transduction inhibition due to cell type-related variations in receptor usage and immunogenicity. This study established parallel NAb detection platforms utilizing human retinal pigment epithelial (ARPE-19) cells and standard 293T cells to systematically evaluate clinical serum samples against ophthalmologically relevant AAV serotypes (2, 5, 8, 9) via luciferase reporter-based transduction inhibition assays. Comparative analysis demonstrated ARPE-19 exhibited 42–48% higher NAb titers against AAV5/9 compared to 293T cells, with distinct serotype-biased neutralization hierarchies observed between cellular models. Furthermore, female-derived sera exhibited significantly elevated NAbs against particular serotypes in the ARPE-19 system. Critically, inter-serotype cross-neutralization correlation patterns differed substantially between cellular platforms. These findings demonstrate that physiologically relevant retinal cellular models provide essential immunological profiling data, revealing NAb characteristics obscured in standard assays. Consequently, employing retinal cell-based platforms is crucial for optimizing AAV serotype selection, patient stratification, and predicting clinical outcomes in ocular gene therapy. Full article
(This article belongs to the Section General Virology)
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17 pages, 1548 KiB  
Article
CD19-ReTARGTPR: A Novel Fusion Protein for Physiological Engagement of Anti-CMV Cytotoxic T Cells Against CD19-Expressing Malignancies
by Anne Paulien van Wijngaarden, Isabel Britsch, Matthias Peipp, Douwe Freerk Samplonius and Wijnand Helfrich
Cancers 2025, 17(14), 2300; https://doi.org/10.3390/cancers17142300 - 10 Jul 2025
Viewed by 411
Abstract
Background/Objectives: The physiological activation of cytotoxic CD8pos T cells (CTLs) relies on the engagement of the TCR/CD3 complex with cognate peptide-HLA class I (pHLA-I) on target cells, triggering cell lysis with appropriate cytokine release and minimized off-target toxicity. In contrast, current [...] Read more.
Background/Objectives: The physiological activation of cytotoxic CD8pos T cells (CTLs) relies on the engagement of the TCR/CD3 complex with cognate peptide-HLA class I (pHLA-I) on target cells, triggering cell lysis with appropriate cytokine release and minimized off-target toxicity. In contrast, current immunotherapies for CD19-expressing hematological malignancies, such as chimeric antigen receptor (CAR) T cells and bispecific T cell engagers (BiTEs), bypass TCR/pHLA interactions, resulting in CTL hyperactivation and excessive cytokine release, which frequently cause severe immune-related adverse events (irAEs). Thus, there is a pressing need for T cell-based therapies that preserve physiological activation while maintaining antitumor efficacy. Methods: To address this, we developed CD19-ReTARGTPR, a novel fusion protein consisting of the immunodominant cytomegalovirus (CMV) pp65-derived peptide TPRVTGGAM (TPR) covalently presented by a soluble HLA-B*07:02/β2-microglobulin complex fused to a high-affinity CD19-targeting Fab antibody fragment. The treatment of CD19-expressing cancer cells with CD19-ReTARGTPR makes them recognizable for pre-existing anti-CMVpp65 CTLs via physiological TCR-pHLA engagement. Results: Our preclinical data demonstrate that CD19-ReTARGTPR efficiently redirects anti-CMV CTLs to eliminate CD19-expressing cancer cells, including both established cell lines and primary chronic lymphocytic leukemia (CLL) cells. Unlike CD19-directed CAR T cells or the CD19/CD3 BiTE blinatumomab, CD19-ReTARGTPR mediated robust cytotoxic activity without triggering supraphysiological cytokine release. Importantly, this approach retained efficacy even against cancer cells with low CD19 expression. Conclusions: In summary, we provide a robust proof-of-concept study and show that CD19-ReTARGTPR offers a promising alternative strategy for T cell redirection, enabling the selective and effective killing of CD19-expressing malignancies while minimizing cytokine-driven toxicities through physiological CTL activation pathways. Full article
(This article belongs to the Special Issue New Insights of Hematology in Cancer)
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29 pages, 5028 KiB  
Article
Moloney Murine Leukemia Virus-like Nanoparticles Pseudo-Typed with SARS-CoV-2 RBD for Vaccination Against COVID-19
by Bernhard Kratzer, Pia Gattinger, Peter A. Tauber, Mirjam Schaar, Al Nasar Ahmed Sehgal, Armin Kraus, Doris Trapin, Rudolf Valenta and Winfried F. Pickl
Int. J. Mol. Sci. 2025, 26(13), 6462; https://doi.org/10.3390/ijms26136462 - 4 Jul 2025
Viewed by 596
Abstract
Virus-like nanoparticles (VNPs) based on Moloney murine leukemia virus represent a well-established platform for the expression of heterologous molecules such as cytokines, cytokine receptors, peptide MHC (pMHC) and major allergens, but their application for inducing protective anti-viral immunity has remained understudied as of [...] Read more.
Virus-like nanoparticles (VNPs) based on Moloney murine leukemia virus represent a well-established platform for the expression of heterologous molecules such as cytokines, cytokine receptors, peptide MHC (pMHC) and major allergens, but their application for inducing protective anti-viral immunity has remained understudied as of yet. Here, we variably fused the wildtype SARS-CoV-2 spike, its receptor-binding domain (RBD) and nucleocapsid (NC) to the minimal CD16b-GPI anchor acceptor sequence for expression on the surface of VNP. Moreover, a CD16b-GPI-anchored single-chain version of IL-12 was tested for its adjuvanticity. VNPs expressing RBD::CD16b-GPI alone or in combination with IL-12::CD16b-GPI were used to immunize BALB/c mice intramuscularly and subsequently to investigate virus-specific humoral and cellular immune responses. CD16b-GPI-anchored viral molecules and IL-12-GPI were well-expressed on HEK-293T-producer cells and purified VNPs. After the immunization of mice with VNPs, RBD-specific antibodies were only induced with RBD-expressing VNPs, but not with empty control VNPs or VNPs solely expressing IL-12. Mice immunized with RBD VNPs produced RBD-specific IgM, IgG2a and IgG1 after the first immunization, whereas RBD-specific IgA only appeared after a booster immunization. Protein/peptide microarray and ELISA analyses confirmed exclusive IgG reactivity with folded but not unfolded RBD and showed no specific IgG reactivity with linear RBD peptides. Notably, booster injections gradually increased long-term IgG antibody avidity as measured by ELISA. Interestingly, the final immunization with RBD–Omicron VNPs mainly enhanced preexisting RBD Wuhan Hu-1-specific antibodies. Furthermore, the induced antibodies significantly neutralized SARS-CoV-2 and specifically enhanced cellular cytotoxicity (ADCC) against RBD protein-expressing target cells. In summary, VNPs expressing viral proteins, even in the absence of adjuvants, efficiently induce functional SARS-CoV-2-specific antibodies of all three major classes, making this technology very interesting for future vaccine development and boosting strategies with low reactogenicity. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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13 pages, 2026 KiB  
Article
Pre-Existing Anti-Inflammatory Immune Conditions Influence Early Antibody Avidity and Isotype Profile Following Comirnaty® Vaccination in Mice
by Mariangeles Castillo, María C. Miraglia, Florencia C. Mansilla, Cecilia P. Randazzo, Leticia V. Bentancor, Teresa Freire and Alejandra V. Capozzo
Vaccines 2025, 13(7), 677; https://doi.org/10.3390/vaccines13070677 - 24 Jun 2025
Viewed by 545
Abstract
Background/Objectives: Vaccine immunogenicity is often suboptimal in vulnerable populations such as the elderly, infants, and individuals in low- and middle-income countries. One contributing factor may be pre-existing immunomodulatory conditions, including helminth infections. This study investigates the impact of Fasciola hepatica (F. hepatica [...] Read more.
Background/Objectives: Vaccine immunogenicity is often suboptimal in vulnerable populations such as the elderly, infants, and individuals in low- and middle-income countries. One contributing factor may be pre-existing immunomodulatory conditions, including helminth infections. This study investigates the impact of Fasciola hepatica (F. hepatica) derived molecules on the early humoral response to the COVID-19 mRNA vaccine Comirnaty® in a mouse model. Methods: BALB/c mice were pretreated with a F. hepatica protein extract (FH) or complete Freund’s adjuvant (CFA) prior to vaccination. Cytokine production and antibody responses were assessed at 0, 14, and 21 days post-vaccination (dpv) through serum analysis and ex vivo splenocyte stimulation with the SARS-CoV-2 receptor-binding domain (RBD) or LPS. Results: At 0 dpv, FH-treated mice showed increased serum IL-10, while CFA treatment induced IL-12. FH- but not CFA-treated splenocytes secreted IL-10 upon RBD or LPS stimulation. At 21 dpv, FH-treated mice lacked IFN-γ production but maintained IL-10 and showed elevated IL-4, consistent with a Th2-skewed profile. Although total anti-RBD IgG levels were similar between groups, FH-treated mice exhibited reduced IgG avidity and a higher IgG1/IgG2 ratio. CFA-treated mice showed delayed avidity maturation. Conclusions: Prior exposure to F. hepatica antigens can modulate the early immune response to Comirnaty®, affecting both cellular activation and antibody quality. This altered response may reflect a reduced early protective capacity of the vaccine, which might need to be considered when designing or evaluating vaccination strategies using mRNA vaccines in helminth-endemic regions. Full article
(This article belongs to the Section Vaccine Advancement, Efficacy and Safety)
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16 pages, 4389 KiB  
Article
Multivalent COBRA Hemagglutinin and Neuraminidase Influenza Vaccines Adjuvanted with TLR9 Agonist CpG 1018
by Pedro L. Sanchez, Amanda Lynch and Ted M. Ross
Vaccines 2025, 13(7), 662; https://doi.org/10.3390/vaccines13070662 - 20 Jun 2025
Viewed by 1313
Abstract
Background/Objectives: There is a need for effective seasonal influenza virus vaccines that provide broad and long-lasting protection against influenza virus infections. Methods: In this study, next-generation influenza hemagglutinin (HA) and neuraminidase (NA) vaccine candidates designed using the computationally optimized broadly reactive antigen (COBRA) [...] Read more.
Background/Objectives: There is a need for effective seasonal influenza virus vaccines that provide broad and long-lasting protection against influenza virus infections. Methods: In this study, next-generation influenza hemagglutinin (HA) and neuraminidase (NA) vaccine candidates designed using the computationally optimized broadly reactive antigen (COBRA) methodology were formulated with the TLR9 agonist, CpG 1018. These adjuvanted COBRA HA/NA vaccines were administered intramuscularly or intranasally to mice with pre-existing anti-influenza immunity or immunologically naïve mice. Results: Mice with pre-existing immune responses to historical influenza virus strains vaccinated intranasal (IN) with COBRA HA/NA vaccines adjuvanted with CpG 1018 had enhanced IgG titers in their bronchoalveolar lavages (BALF) compared to unadjuvanted vaccines. These mice also had increased serum IgG titers that were like antibody titers observed in mice that were vaccinated intramuscularly. Mice that were vaccinated intranasally with this adjuvanted vaccine also had antibodies with significantly higher hemagglutination inhibition activity against a broad range of H1N1 and H3N2 influenza viruses and more HA and NA specific antibody-secreting cells compared to unadjuvanted vaccine. Following the H1N1 influenza virus challenge, pre-immune mice that were vaccinated with the COBRA HA/NA vaccine with CpG 1018 were protected from morbidity and mortality and had no detectable viral lung titers. Conclusions: Overall, CpG 1018 adjuvanted COBRA HA/NA elicited enhanced protective antibodies compared to the unadjuvanted vaccine against several drifted H1N1 and H3N2 influenza viruses in pre-immune mice that were either intramuscularly or intranasally vaccinated with a balanced Th1/Th2 immune response. Full article
(This article belongs to the Section Influenza Virus Vaccines)
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18 pages, 2967 KiB  
Article
Adenoviruses Encapsulated in PEGylated DOTAP-Folate Liposomes Are Protected from the Pre-Existing Humoral Immune Response
by Abraham T. Phung, Jaimin R. Shah, Tao Dong, Omonigho Aisagbonhi, William C. Trogler, Andrew C. Kummel and Sarah L. Blair
Pharmaceutics 2025, 17(6), 769; https://doi.org/10.3390/pharmaceutics17060769 - 11 Jun 2025
Viewed by 712
Abstract
Background/Objectives: While adenovirus (Ad) therapies have been proven to be effective in local administration, systemic Ad treatments have shown limited success due to pre-existing antibodies in the human blood that neutralize the virus. We developed a liposome coating procedure that protects the [...] Read more.
Background/Objectives: While adenovirus (Ad) therapies have been proven to be effective in local administration, systemic Ad treatments have shown limited success due to pre-existing antibodies in the human blood that neutralize the virus. We developed a liposome coating procedure that protects the Ad from pre-existing neutralizing antibodies in human blood. To assess the in vivo stability of the liposomes, the present study used a novel in vivo method to quantitatively assess the protective capabilities of liposome-encapsulated Ad (DfAd) from neutralizing antibodies. Methods: The assay systemically administers DfAd with a green fluorescent protein transgene (DfAd-GFP) into pre-immunized mice and allows it to circulate in the presence of neutralizing antibodies; the infected blood is extracted and used to transduce HEK293 cells, which emits fluorescence in the presence of protected, un-neutralized Ad. Results: The PEGylated liposome formulation provides 12× protection in vivo relative to unencapsulated Ads. In vitro optimization of the liposome coating reveals a strong correlation between the structural stability of liposomes and protection against anti-Ad neutralizing antibodies, where DSPE-PEG2000-carboxylic acid (DSPE-PEG2000-CA) is a critical component for liposome stability and increasing protection against antibody neutralization of the encapsulated Ad. Conclusions: The findings in the present study confirm that the DfAd liposome can protect against neutralizing antibodies in blood circulation. The novel in vivo assay for liposome protection against neutralizing antibodies and in vitro experiments in the present study provide new tools and insights toward designing liposome–Ad complexes for the systemic treatment of cancer. Full article
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37 pages, 477 KiB  
Review
Recombinant Mycobacterium bovis BCG-Based HIV Vaccine: Failures and Promising Approaches for a Successful Vaccine Strategy
by Joan Joseph-Munné, Milena Maya-Hoyos, Narcís Saubi, Santiago Perez, Miguel Angel Martinez Lopez, Eder Baron and Carlos Yesid Soto
Vaccines 2025, 13(6), 606; https://doi.org/10.3390/vaccines13060606 - 3 Jun 2025
Viewed by 683
Abstract
During 2022, AIDS claimed a life every minute and about 9.2 million HIV-infected people were not on treatment. In addition, a person living with HIV is estimated to be 20–30 times more susceptible to developing active tuberculosis. Every year, 130,000 infants are newly [...] Read more.
During 2022, AIDS claimed a life every minute and about 9.2 million HIV-infected people were not on treatment. In addition, a person living with HIV is estimated to be 20–30 times more susceptible to developing active tuberculosis. Every year, 130,000 infants are newly infected, with vertical transmission being the main cause of pediatric HIV infection. Thus, the development of an effective, safe, and accessible vaccine for neonates and/or adults is an urgent need to prevent or control HIV infection or progression to AIDS. An effective HIV vaccine should induce long-lasting mucosal immunity, broadly neutralizing antibodies, innate immunity, and robust stimulation of CD4+ and CD8+ T-cell responses. Recombinant BCG is a promising live-attenuated bacterial vaccine vector because of its capacity to stimulate T-cell immunity. As a slow-growing microorganism, it provides prolonged low-level antigenic exposure upon infecting macrophages and APCs, potentially stimulating both effector and memory T-cell responses. BCG is considered safe and is currently administered to 80% of infants in countries where it is part of the national immunization program. Additionally, BCG offers several benefits as a live vaccine vehicle since it is cost-effective, easy to mass-produce, and heat stable. It is also well-suited for newborns, as maternal antibodies do not interfere with its efficacy. Furthermore, BCG has a strong safety profile, having been administered to over three billion people as a TB vaccine. In this review, we provide an extensive summary of the literature relating to immunogenicity studies in animal models performed since 2011. Moreover, we provide a comprehensive analysis of the key factors influencing the design of recombinant BCG as a live vaccine vehicle: (i) expression vectors; (ii) selection of HIV immunogen; (iii) promoters to regulate gene expression; (iv) BCG strain and BCG codon optimization; (v) genetic plasmid stability; (vi) influence of preexisting immunity, route, and dose immunization; and (vii) safety profile. Full article
(This article belongs to the Special Issue The Development of HIV Vaccines: Advances and Challenges)
18 pages, 4846 KiB  
Article
The Nrf2 Activator CDDO-Imidazole Suppresses Inflammation-Induced Red Blood Cell Alloimmunization
by Che-Yu Chang, Rosario Hernández-Armengol, Kausik Paul, June Young Lee, Karina Nance, Tomohiro Shibata, Peibin Yue, Christian Stehlik and David R. Gibb
Antioxidants 2025, 14(6), 678; https://doi.org/10.3390/antiox14060678 - 3 Jun 2025
Viewed by 627
Abstract
Experimental Objective: During red blood cell (RBC) transfusion, inflammation promotes the production of anti-RBC alloantibodies that can cause significant hemolytic events. Avoiding RBC antigen exposure is the only strategy to prevent RBC alloimmunization in transfusion recipients. Identifying mechanisms that inhibit alloimmunization may lead [...] Read more.
Experimental Objective: During red blood cell (RBC) transfusion, inflammation promotes the production of anti-RBC alloantibodies that can cause significant hemolytic events. Avoiding RBC antigen exposure is the only strategy to prevent RBC alloimmunization in transfusion recipients. Identifying mechanisms that inhibit alloimmunization may lead to novel prophylactic interventions. One potential regulatory mechanism is the activation of the transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2), a master regulator of antioxidant pathways. Pharmacologic Nrf2 activators induce antioxidant production and improve the sequelae of inflammatory diseases. Thus, we tested the hypothesis that a Nrf2 activator, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]-imidazole (CDDO-Im), regulates inflammation-induced RBC alloimmunization. Methods: WT and Nrf2-deficient mice were treated with inflammatory stimuli and CDDO-Im prior to transfusion with RBCs expressing the KEL antigen (KEL+ RBCs). Anti-KEL IgM and IgG were measured in the serum of transfused mice. Nrf2-activated gene expression and interferon activity were measured in mice and human macrophages pre-treated with CDDO-Im and interferon stimuli. Results: Here, we report that CDDO-Im induces Nrf2-activated gene expression and inhibits type 1 interferon activity, which promotes RBC alloimmunization in transfusion models. In mice transfused with KEL+ RBCs, pre-treatment with CDDO-Im inhibited inflammation-induced anti-KEL antibody production and increased the post-transfusion recovery of KEL+ RBCs in a Nrf2-dependent manner. CDDO-Im also inhibited RBC alloimmunization in mice with pre-existing inflammation. Conclusions: These results indicate that the activation of the Nrf2 antioxidant pathway regulates RBC alloimmunization to the KEL antigen in a pre-clinical model. If these findings translate to other models and human studies, Nrf2 activators may represent a potential prophylactic intervention to inhibit alloimmunization. Full article
(This article belongs to the Special Issue Blood Cells and Redox Homeostasis in Health and Disease, 2nd Edition)
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22 pages, 3022 KiB  
Article
Circulating Antibodies Against Common Cold Coronaviruses Do Not Interfere with Immune Responses to Primary or Booster SARS-CoV-2 mRNA Vaccines
by Bindu Adhikari, Eugene M. Oltz, Richard J. Gumina, Maryssa K. Kick, Linda J. Saif and Anastasia N. Vlasova
Vaccines 2025, 13(5), 547; https://doi.org/10.3390/vaccines13050547 - 21 May 2025
Viewed by 880
Abstract
Background: Pre-existing cross-reactive antibodies (Abs) against common cold coronaviruses (CCCoVs) have been hypothesized to influence the immune responses to SARS-CoV-2 vaccine-induced Ab responses. Methods: Serum samples from healthy healthcare workers (HCWs, n = 64) receiving mRNA vaccines were collected at seven time points: [...] Read more.
Background: Pre-existing cross-reactive antibodies (Abs) against common cold coronaviruses (CCCoVs) have been hypothesized to influence the immune responses to SARS-CoV-2 vaccine-induced Ab responses. Methods: Serum samples from healthy healthcare workers (HCWs, n = 64) receiving mRNA vaccines were collected at seven time points: pre-COVID-19-vaccination (Pre), post-first dose (Vax1), post-second dose (Vax2), and 6-, 9-, 12-, and 15-months post-Vax2. Booster vaccine doses (n = 23) were received 1–80 days prior to the 9 m sample collection time point. We used peptide-based enzyme-linked immunosorbent assays (ELISAs) to measure SARS-CoV-2/CCCoV-specific IgG/IgA/IgM and SARS-CoV-2 IgG4 (associated with immune tolerance) Ab levels in the HCW serum samples. Additionally, we measured Epstein–Barr/influenza A (unrelated pathogens) virus-specific IgG Ab levels. Results: We observed that vaccination significantly increased SARS-CoV-2 IgG Ab levels at the Vax1 (p ≤ 0.0001) and Vax2 (p ≤ 0.0001) time points compared to Pre-Vax. These Ab levels declined at 6 months post-vaccination but increased again following the booster vaccine dose around the 9-month post-Vax2 time point in a cohort (n = 23) of the HCWs. However, this increase was modest compared to those induced by the primary vaccine series. Interestingly, a moderate but continuous increase in SARS-CoV-2 S IgG4 Ab levels was observed throughout this study, becoming statistically significant by the 15-month time point (p = 0.03). Further, a significant increase in CCCoV IgG (but not IgA/IgM) Ab levels was observed at the Vax1 time point, suggestive of cross-reactive or non-specific immune responses. Finally, we observed no negative correlation between the levels of pre-existing CCCoV-specific Abs and the vaccine-induced Ab response (Vax1/Vax2). Conclusions: Pre-existing CCCoV Abs do not interfere with the development of vaccine-induced immunity. However, vaccine-associated Abs wane over time, which may be associated with the increasing IgG4 Ab response. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
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20 pages, 986 KiB  
Review
Past, Present, and Future of Viral Vector Vaccine Platforms: A Comprehensive Review
by Justin Tang, Md Al Amin and Jian L. Campian
Vaccines 2025, 13(5), 524; https://doi.org/10.3390/vaccines13050524 - 15 May 2025
Viewed by 2625
Abstract
Over the past several decades, viral vector-based vaccines have emerged as some of the most versatile and potent platforms in modern vaccinology. Their capacity to deliver genetic material encoding target antigens directly into host cells enables strong cellular and humoral immune responses, often [...] Read more.
Over the past several decades, viral vector-based vaccines have emerged as some of the most versatile and potent platforms in modern vaccinology. Their capacity to deliver genetic material encoding target antigens directly into host cells enables strong cellular and humoral immune responses, often superior to what traditional inactivated or subunit vaccines can achieve. This has accelerated their application to a wide array of pathogens and disease targets, from well-established threats like HIV and malaria to emerging infections such as Ebola, Zika, and SARS-CoV-2. The COVID-19 pandemic further highlighted the agility of viral vector platforms, with several adenovirus-based vaccines quickly authorized and deployed on a global scale. Despite these advances, significant challenges remain. One major hurdle is pre-existing immunity against commonly used vector backbones, which can blunt vaccine immunogenicity. Rare but serious adverse events, including vector-associated inflammatory responses and conditions like vaccine-induced immune thrombotic thrombocytopenia (VITT), have raised important safety considerations. Additionally, scaling up manufacturing, ensuring consistency in large-scale production, meeting rigorous regulatory standards, and maintaining equitable global access to these vaccines present profound logistical and ethical dilemmas. In response to these challenges, the field is evolving rapidly. Sophisticated engineering strategies, such as integrase-defective lentiviral vectors, insect-specific flaviviruses, chimeric capsids to evade neutralizing antibodies, and plug-and-play self-amplifying RNA approaches, seek to bolster safety, enhance immunogenicity, circumvent pre-existing immunity, and streamline production. Lessons learned from the COVID-19 pandemic and prior outbreaks are guiding the development of platform-based approaches designed for rapid deployment during future public health emergencies. This review provides an exhaustive, in-depth examination of the historical evolution, immunobiological principles, current platforms, manufacturing complexities, regulatory frameworks, known safety issues, and future directions for viral vector-based vaccines. Full article
(This article belongs to the Special Issue Strategies of Viral Vectors for Vaccine Development)
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136 pages, 24434 KiB  
Perspective
Alzheimer’s Is a Multiform Disease of Sustained Neuronal Integrated Stress Response Driven by the C99 Fragment Generated Independently of AβPP; Proteolytic Production of Aβ Is Suppressed in AD-Affected Neurons: Evolution of a Theory
by Vladimir Volloch and Sophia Rits-Volloch
Int. J. Mol. Sci. 2025, 26(9), 4252; https://doi.org/10.3390/ijms26094252 - 29 Apr 2025
Viewed by 1342
Abstract
The present Perspective analyzes the remarkable evolution of the Amyloid Cascade Hypothesis 2.0 (ACH2.0) theory of Alzheimer’s disease (AD) since its inception a few years ago, as reflected in the diminishing role of amyloid-beta (Aβ) in the disease. In the initial iteration of [...] Read more.
The present Perspective analyzes the remarkable evolution of the Amyloid Cascade Hypothesis 2.0 (ACH2.0) theory of Alzheimer’s disease (AD) since its inception a few years ago, as reflected in the diminishing role of amyloid-beta (Aβ) in the disease. In the initial iteration of the ACH2.0, Aβ-protein-precursor (AβPP)-derived intraneuronal Aβ (iAβ), accumulated to neuronal integrated stress response (ISR)-eliciting levels, triggers AD. The neuronal ISR, in turn, activates the AβPP-independent production of its C99 fragment that is processed into iAβ, which drives the disease. The second iteration of the ACH2.0 stemmed from the realization that AD is, in fact, a disease of the sustained neuronal ISR. It introduced two categories of AD—conventional and unconventional—differing mainly in the manner of their causation. The former is caused by the neuronal ISR triggered by AβPP-derived iAβ, whereas in the latter, the neuronal ISR is elicited by stressors distinct from AβPP-derived iAβ and arising from brain trauma, viral and bacterial infections, and various types of inflammation. Moreover, conventional AD always contains an unconventional component, and in both forms, the disease is driven by iAβ generated independently of AβPP. In its third, the current, iteration, the ACH2.0 posits that proteolytic production of Aβ is suppressed in AD-affected neurons and that the disease is driven by C99 generated independently of AβPP. Suppression of Aβ production in AD seems an oxymoron: Aβ is equated with AD, and the later is inconceivable without the former in an ingrained Amyloid Cascade Hypothesis (ACH)-based notion. But suppression of Aβ production in AD-affected neurons is where the logic leads, and to follow it we only need to overcome the inertia of the preexisting assumptions. Moreover, not only is the generation of Aβ suppressed, so is the production of all components of the AβPP proteolytic pathway. This assertion is not a quantum leap (unless overcoming the inertia counts as such): the global cellular protein synthesis is severely suppressed under the neuronal ISR conditions, and there is no reason for constituents of the AβPP proteolytic pathway to be exempted, and they, apparently, are not, as indicated by the empirical data. In contrast, tau protein translation persists in AD-affected neurons under ISR conditions because the human tau mRNA contains an internal ribosomal entry site in its 5′UTR. In current mouse models, iAβ derived from AβPP expressed exogenously from human transgenes elicits the neuronal ISR and thus suppresses its own production. Its levels cannot principally reach AD pathology-causing levels regardless of the number of transgenes or the types of FAD mutations that they (or additional transgenes) carry. Since the AβPP-independent C99 production pathway is inoperative in mice, the current transgenic models have no potential for developing the full spectrum of AD pathology. What they display are only effects of the AβPP-derived iAβ-elicited neuronal ISR. The paper describes strategies to construct adequate transgenic AD models. It also details the utilization of human neuronal cells as the only adequate model system currently available for conventional and unconventional AD. The final alteration of the ACH2.0, introduced in the present Perspective, is that AβPP, which supports neuronal functionality and viability, is, after all, potentially produced in AD-affected neurons, albeit not conventionally but in an ISR-driven and -compatible process. Thus, the present narrative begins with the “omnipotent” Aβ capable of both triggering and driving the disease and ends up with this peptide largely dislodged from its pedestal and retaining its central role in triggering the disease in only one, although prevalent (conventional), category of AD (and driving it in none). Among interesting inferences of the present Perspective is the determination that “sporadic AD” is not sporadic at all (“non-familial” would be a much better designation). The term has fatalistic connotations, implying that the disease can strike at random. This is patently not the case: The conventional disease affects a distinct subpopulation, and the basis for unconventional AD is well understood. Another conclusion is that, unless prevented, the occurrence of conventional AD is inevitable given a sufficiently long lifespan. This Perspective also defines therapeutic directions not to be taken as well as auspicious ways forward. The former category includes ACH-based drugs (those interfering with the proteolytic production of Aβ and/or depleting extracellular Aβ). They are legitimate (albeit inefficient) preventive agents for conventional AD. There is, however, a proverbial snowball’s chance in hell of them being effective in symptomatic AD, lecanemab, donanemab, and any other “…mab” or “…stat” notwithstanding. They comprise Aβ-specific antibodies, inhibitors of beta- and gamma-secretase, and modulators of the latter. In the latter category, among ways to go are the following: (1) Depletion of iAβ, which, if sufficiently “deep”, opens up a tantalizing possibility of once-in-a-lifetime preventive transient treatment for conventional AD and aging-associated cognitive decline, AACD. (2) Composite therapy comprising the degradation of C99/iAβ and concurrent inhibition of the neuronal ISR. A single transient treatment could be sufficient to arrest the progression of conventional AD and prevent its recurrence for life. Multiple recurrent treatments would achieve the same outcome in unconventional AD. Alternatively, the sustained reduction/removal of unconventional neuronal ISR-eliciting stressors through the elimination of their source would convert unconventional AD into conventional one, preventable/treatable by a single transient administration of the composite C99/iAβ depletion/ISR suppression therapy. Efficient and suitable ISR inhibitors are available, and it is explicitly clear where to look for C99/iAβ-specific targeted degradation agents—activators of BACE1 and, especially, BACE2. Directly acting C99/iAβ-specific degradation agents such as proteolysis-targeting chimeras (PROTACs) and molecular-glue degraders (MGDs) are also viable options. (3) A circumscribed shift (either upstream or downstream) of the position of transcription start site (TSS) of the human AβPP gene, or, alternatively, a gene editing-mediated excision or replacement of a small, defined segment of its portion encoding 5′-untranslated region of AβPP mRNA; targeting AβPP RNA with anti-antisense oligonucleotides is another possibility. If properly executed, these RNA-based strategies would not interfere with the protein-coding potential of AβPP mRNA, and each would be capable of both preventing and stopping the AβPP-independent generation of C99 and thus of either preventing AD or arresting the progression of the disease in its conventional and unconventional forms. The paper is interspersed with “validation” sections: every conceptually significant notion is either validated by the existing data or an experimental procedure validating it is proposed. Full article
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9 pages, 932 KiB  
Article
Assessing Blood Pressure Effects of Anti-CGRP Antibody Treatment in Migraine: A Retrospective Real-World Analysis
by Katharina Kaltseis, Michael Thomas Eller, Lena Gufler, Gregor Broessner and Florian Frank
Biomedicines 2025, 13(5), 1027; https://doi.org/10.3390/biomedicines13051027 - 24 Apr 2025
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Abstract
Background: Anti-CGRP (receptor) antibodies are approved for the preventive treatment of migraines and are increasingly used due to their favorable safety profile and potent efficacy. However, as CGRP is one of the most potent vasodilators, concerns have been raised regarding the possible impact [...] Read more.
Background: Anti-CGRP (receptor) antibodies are approved for the preventive treatment of migraines and are increasingly used due to their favorable safety profile and potent efficacy. However, as CGRP is one of the most potent vasodilators, concerns have been raised regarding the possible impact of these drugs on arterial blood pressure. Methods: We present a retrospective cohort study at a tertiary headache center including a total of 259 patients with episodic and chronic migraine who received anti-CGRP antibody treatment for migraine prevention. Blood pressure was measured in a hospital using a standardized setting at baseline and at least at two follow-up visits. Significant increase in blood pressure was defined as an increase in systolic blood pressure ≥ 20 mmHg and/or an increase in diastolic blood pressure ≥ 10 mmHg from the baseline value. Results: Mean age of our population was 39.9 years (±12.1), and 217 (83.8%) were female. Blood pressure measurements between T0 and T2, incorporating all CGRP-antibody groups, showed a significant reduction in systolic (−3.3 mmHg; p = 0.001) and diastolic blood pressure (−2.3 mmHg; p = 0.021), respectively. The repeated-measures generalized linear model analysis revealed no significant variations between the CGRP antibodies relative to blood pressure. The most robust factor predicting systolic hypertensive measurements in the course of anti-CGRP antibody treatment was pre-existing hypertension at baseline (sum of mean squares 7.4; p = 0.019). Conclusions: Our data indicate that treatment with anti-CGRP (receptor) antibodies does not significantly increase blood pressure. However, it seems to be important to monitor patients with pre-existing arterial hypertension. Full article
(This article belongs to the Section Molecular and Translational Medicine)
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19 pages, 4140 KiB  
Article
Enhancing the Anticancer Activity of a Carcinoma-Directed Peptide–HLA-I Fusion Protein by Armoring with Mutein IFNα
by Douwe Freerk Samplonius, Anne Paulien van Wijngaarden, Lisanne Koll, Xiurong Ke and Wijnand Helfrich
Int. J. Mol. Sci. 2025, 26(7), 3178; https://doi.org/10.3390/ijms26073178 - 29 Mar 2025
Cited by 1 | Viewed by 656
Abstract
Previously, we reported on the peptide–HLA-I fusion protein EpCAM-ReTARGTPR, which allows us to redirect the cytotoxic activity of pre-existing anti-CMV CD8pos T cell immunity to selectively eliminate EpCAMpos cancer cells. EpCAM-ReTARGTPR consists of the CMV pp65-derived peptide TPRVTGGGAM [...] Read more.
Previously, we reported on the peptide–HLA-I fusion protein EpCAM-ReTARGTPR, which allows us to redirect the cytotoxic activity of pre-existing anti-CMV CD8pos T cell immunity to selectively eliminate EpCAMpos cancer cells. EpCAM-ReTARGTPR consists of the CMV pp65-derived peptide TPRVTGGGAM (TPR) fused in tandem with a soluble HLA-B*07:02/β2-microglobulin (β2M) molecule and an EpCAM-directed Fab antibody fragment. To further enhance its anticancer activity, we equipped EpCAM-ReTARGTPR with the immune-potentiating cytokine muteins IL2(H16A,F42A) and IFNαR149A, respectively. Both cytokines are engineered to have attenuated affinity for their respective cytokine receptors. Compared to EpCAM-ReTARGTPR, in vitro treatment of EpCAMpos carcinoma cell lines with EpCAM-ReTARGTPRvIL2 for 24 h increased the cytotoxic activity of PBMCs containing low levels of TPR-specific CD8pos T cells by ~15%, whereas EpCAM-ReTARGTPRIFNαR149A induced an increase of ~50%. Moreover, treatment for 120 h with EpCAM-ReTARGTPRIFNαR149A inhibited the proliferative capacity of the cancer cell lines OvCAR3 and PC3M by ~91% without compromising the viability of the TPR-specific CD8pos T cells and increased their capacity for IFNγ secretion. Importantly, EpCAM-ReTARGTPRIFNαR149A potently induced the elimination of primary EpCAMpos refractory carcinoma cells from a Merkel cell carcinoma (MCC) patient. Taken together, the armoring of the carcinoma-directed peptide–HLA-I fusion protein EpCAM-ReTARGTPR with IFNαR149A potently enhanced the efficacy of pre-existing anti-CMV CD8pos T cell immunity to selectively eliminate EpCAMpos cancer cells. Full article
(This article belongs to the Special Issue Immunotherapy in Cancer)
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