Search Results (1,245)

Immunogenic cell death (ICD) is a subtype of regulated cell death characterized by the spatiotemporally coordinated emission of damage-associated molecular patterns (DAMPs), such as calreticulin (CALR), ATP, and high-mobility group box-1 (HMGB1), which collectively prime tumor-specific T-cell responses. Autophagy, a lysosome-dependent catabolic process, is increasingly recognized as a key modifier of antitumor immunity and the tumor microenvironment (TME). In preclinical models, autophagy can not only promote ICD by sustaining endoplasmic reticulum (ER) stress, eukaryotic translation initiation factor-2α (eIF2α) phosphorylation, and secretory pathways, but it can also limit ICD by degrading DAMPs, antigenic cargo, and major histocompatibility complex (MHC) molecules. The net outcome is highly context-dependent and determined by the tumor type, the nature and intensity of the stress, and the level at which autophagy is modulated. Herein, we summarize how autophagy affects the three canonical ICD-associated DAMPs, highlight solid-tumor models in which autophagy supports ICD, and contrast them with systems wherein autophagy inhibition is required for immunogenicity. We then focus on hematological malignancies, especially multiple myeloma, where recent reports implicate the autophagy-related protein GABARAP in bortezomib-induced ICD. Finally, we discuss the translational implications, including rational combinations of autophagy modulators with ICD-inducing chemotherapies, targeted drugs, and cellular immunotherapies, and outline the remaining challenges for safely harnessing the autophagy–ICD axis in the clinical setting. Full article

Porcine circovirus 2 (PCV2) is a DNA virus that is classified in the genus Circovirus of the Circoviridae family, which is a causative agent of Porcine Circovirus-Associated disease (PCVAD). PCVAD continues to cause substantial losses in global pig farming, with PCV2d being the prevalent genotype worldwide, including in Vietnam. In this study, we focused on generating a recombinant PCV2d Cap protein fused to the GCN4pII motif (Cap2d-pII) in a plant-based system and evaluating its immunogenicity. The Cap2d-pII gene was cloned into a plant expression vector and introduced into Agrobacterium tumefaciens for transient expression in Nicotiana benthamiana leaves. Western blot analysis confirmed the high accumulation of the Cap2d-pII protein, which was purified by Immobilized affinity chromatography and used for immunizing mice. ELISA and immunoperoxidase monolayer assay results demonstrated that immunization with the recombinant protein elicited robust humoral and cellular immune responses. At 56 days after immunization, mice vaccinated with the Cap2d-pII protein generated PCV2d-specific IgG titers and IFN-γ responses that were consistent with those in mice receiving the commercial inactivated vaccine. These observations confirm that the plant-expressed Cap2d-pII antigen effectively activates both antibody- and T cell-mediated immune pathways. Collectively, this study identifies the Cap2d-pII protein as a promising plant-derived vaccine candidate for the development of effective and affordable PCV2d subunit vaccines. Full article

The success of cancer vaccines relies on the ability of dendritic cells (DCs) to efficiently prime cytotoxic CD8 T cell responses against tumors. However, in solid tumors this process is often undermined by tumor-driven immunosuppression and intrinsic defects in DC activation. Among the signaling pathways implicated in DC dysfunction, β-catenin signaling has emerged as a key regulator of immune tolerance in DCs. In parallel, inhibitory receptors such as PD-L1 and TIM-3 on DCs have been recognized as critical DC-intrinsic brakes on CD8 T cell priming and on responses to immune checkpoint blockade (ICB). Recent work has identified a DC-intrinsic immunoregulatory circuit in which β-catenin activation in DCs—particularly in cross-presenting cDC1s—induces expression of TIM-3, thereby suppressing CD8 T cell cross-priming and limiting anti-tumor CD8 T cell immunity. This β-catenin–TIM-3 axis represents a previously underappreciated layer of negative regulation that may help explain, at least in part, the limited efficacy of many current DC-based cancer vaccines. In this review, we examine how β-catenin activation in DCs, particularly in cDC1s, induces TIM-3 and related inhibitory programs that suppress cross-priming of tumor antigen-specific CD8 T cells and constrain the efficacy of DC-based vaccines. We further discuss how selectively targeting this β-catenin–TIM-3 checkpoint axis—alone or together with PD-L1 and other β-catenin–linked receptors—could restore DC function and inform rational combinations of DC-based vaccination with ICB and other T cell-based immunotherapies. Full article

Melanoma remains one of the deadliest cutaneous malignancies worldwide, and despite advances in systemic therapy, recurrence and treatment resistance remain frequent challenges. Following the success of COVID-19 mRNA vaccines, mRNA-based cancer vaccines targeting melanoma antigens have emerged as a promising therapeutic direction. This review summarizes current evidence on mRNA melanoma vaccines, focusing on two leading delivery platforms: lipid nanoparticles (LNPs) and dendritic cell (DC) vaccines. A comprehensive search of MEDLINE, Embase, and Scopus from 2015 to 2025 identified clinical trials, preclinical studies, and review articles evaluating mRNA vaccine constructs and delivery strategies. Completed clinical studies demonstrate that personalized LNP-formulated mRNA vaccines can enhance neoantigen-specific T-cell responses and improve recurrence-free survival, particularly when combined with immune checkpoint inhibitors. DC-based mRNA vaccines also show potent immunogenicity, with stronger responses observed when DC maturation is optimized. Ongoing trials continue to investigate next-generation LNP formulations, DC priming strategies, and personalized neoantigen approaches. Overall, current evidence indicates that both LNP and DC platforms can augment antitumor immunity by broadening T-cell responses and enhancing checkpoint inhibition. Continued refinement of delivery vehicles, neoantigen selection, and scalable manufacturing processes will be essential to realizing the full clinical potential of mRNA vaccines in melanoma. Full article

Human cytomegalovirus (HCMV) infection is a significant complication in transplant recipients. Following HCMV reactivation, the recovery of T-cell responses serves as a key indicator of protection from HCMV disease. This study aimed to assess the HCMV-specific CD4⁺ and CD8⁺ T-cell responses and their cytokine production (IFNγ, TNFα, IL2) against various HCMV proteins (IE-1, pp65, gB, gH/gL/pUL128L) in solid organ transplant recipients (SOTRs) and hematopoietic stem cell transplant recipients (HSCTRs) with active HCMV infection. The cohort consisted of 16 SOTR and 16 HSCTR categorized into two groups: (i) Controllers, who spontaneously controlled the infection, and (ii) Non-Controllers, who required antiviral treatment. T-cell responses were analyzed following stimulation with peptide pools and intracellular cytokine staining. Prior to transplantation, all patients exhibited a significantly higher frequency of CD4⁺ T cells specific to pp65 compared to gH and gL/pUL128L. During the peak of infection, T-cell frequencies across all peptides were similar, but at infection resolution, the frequency of pp65 and gB-specific CD4⁺IFNγ⁺ T cells was significantly higher than gL/pUL128L. Additionally, pp65 and IE-1-specific CD8⁺IFNγ⁺ T-cell responses were significantly greater than those against gH and gL/pUL128L at the resolution of infection. Notably, Controllers exhibited significantly higher frequencies of monofunctional pp65-specific T cells, particularly in CD8⁺ T cells producing IFNγ and TNFα. The response to pp65, especially IFNγ production, may serve as a key marker for identifying patients capable of controlling HCMV infection. Full article

Background: Patients with end-stage renal disease (ESRD) on hemodialysis are at increased risk for severe influenza, and underlying immune dysfunction may limit vaccine-induced protection. Methods: This observational open-label study evaluated immune responses in 93 hemodialysis patients vaccinated with seasonal inactivated influenza vaccine (IIV) during the 2019–2020 (n = 22) and 2023–2024 (n = 71) seasons. Immune responses were comprehensively assessed using hemagglutination inhibition and microneutralization assays to measure antibody levels, together with flow cytometry analysis of key immune cell populations, including plasmablasts, T-follicular helper cells (Tfh), and effector memory T cells (Tem). Results: During the 2019–2020 season, antibody responses in hemodialysis patients were comparable to those in healthy volunteers in both younger (18–60 years) and older (over 60) age groups. By day 7 post-vaccination, there was a pronounced increase in activated Tfh1 cells, coinciding with a surge in plasmablasts and a rise in antigen-specific B cells. This was accompanied by a T-cell response mediated by IFNγ-producing and polyfunctional CD4+ Tem cells. In the 2023–2024 season, revaccination was associated with higher baseline antibody levels but did not alter subsequent response kinetics to A/H1N1pdm, A/H3N2, and B/Yamagata antigens. In contrast, responses to B/Victoria were higher in revaccinated patients throughout the entire observation period. Conclusions: Our findings confirm that standard-dose IIV vaccination is beneficial for hemodialysis patients, inducing robust and adequate humoral and T-cell immune responses. Full article

Background/Objectives: Small-cell lung cancer (SCLC) is an aggressive neuroendocrine malignancy characterized by rapid proliferation, early metastasis, and near-universal relapse after initial therapy. While chemo-immunotherapy modestly improves first-line outcomes, survival after progression remains poor and highlights the urgent need for biomarker-directed strategies. Methods: A comprehensive literature search was conducted using major medical databases looking at key relevant studies on SCLC antibody studies. All authors reviewed the literature, assessed study quality, and interpreted the results from each study. Results: Recent advances in antibody–drug conjugates (ADCs) and T-cell engagers (TCEs) have transformed therapeutic development by targeting antigens selectively expressed on SCLC cells, enabling more precise and potentially durable tumor control. DLL3 has emerged as the most clinically relevant target to date, with the bispecific TCE tarlatamab demonstrating meaningful and durable response, manageable cytokine-release toxicity, and ultimately achieving accelerated FDA approval for previously treated extensive-stage SCLC. Concurrently, DLL3-directed ADCs have shown variable efficacy, underscoring the importance of payload selection, linker chemistry, and antigen density. Beyond DLL3, next-generation ADCs targeting TROP2, B7-H3, and SEZ6 have reported encouraging early-phase activity, including response rates exceeding those of existing second-line cytotoxic options, though myelosuppression, interstitial lung disease, and hepatic toxicity remain key considerations. Conclusions: Collectively, these emerging immunotherapies illustrate a shift toward antigen-specific targeting in a disease historically defined by limited therapeutic innovation. Continued optimization of antigen selection, payload and linker engineering, and biomarker-driven trial design will be critical for translating early promise into durable clinical benefit and reshaping the treatment landscape for SCLC. Full article

Background: Seasonal influenza remains a significant public health problem, and the constant antigenic drift of viruses requires regular vaccine updates. mRNA vaccines offer a promising platform for the development of new, effective influenza vaccines. Administration of the naked mRNA vaccine using a needle-free jet injection system further enhances its safety, reduces cost, and eliminates the need for lipid nanoparticles, which are traditionally used for mRNA delivery. Lyophilization of naked mRNA allows for long-term storage at +4 °C. Methods: We designed and produced an mRNA vaccine against seasonal influenza, designated mRNA-Vector-Flu, encoding the hemagglutinin (HA) of the A/Wisconsin/67/2022(H1N1)pdm09, A/Darwin/9/2021(H3N2), and B/Austria/1359417/2021 strains. The vaccine was lyophilized and stored for 1 month in a refrigerator (+4 °C). A comparative immunogenicity study was conducted between synthesized immediately before use prepared and lyophilized naked mRNA-Vector-Flu. The preparations were administered to BALB/c mice using a jet needleless injection twice, 3 weeks apart. Immunogenicity was assessed on day 35 of the study. Results: A comparative immunogenicity study of naked mRNA-Vector-Flu demonstrated that both the synthesized immediately before use prepared formulation and the lyophilized form, stored at +4 °C for a month, induced similar levels of virus-specific antibodies and generated a pronounced T-cell immune response. Conclusions: Delivery of the naked mRNA vaccine using a needle-free jet injection ensures a high-level immune response, which improves its safety, reduces its cost, and eliminates the need for lipid nanoparticles traditionally used for mRNA delivery. At the same time, lyophilization of the naked mRNA vaccine preserves its biological activity and ensures its storage for at least a month at +4 °C temperatures. Our results demonstrate that our proposed approach can be considered a promising direction for the development and improvement of the mRNA vaccine platform. Full article

Background: The development of effective tuberculosis (TB) vaccines beyond BCG remains an urgent global health priority, especially for prevention of pulmonary TB in adults. While most current strategies focus on enhancing T-cell immunity, the potential of trained immunity to broadly augment both innate and adaptive responses remains underexplored in TB vaccinology. Given the central role of dendritic cells (DCs) as bridges between innate and adaptive immunity, we hypothesized that inducing trained immunity in DCs could optimize subsequent T-cell responses. Previous studies have identified Rv2299c as a promising adjuvant of other antigens by promoting DC maturation; however, whether it could be used as a standalone protective antigen of TB vaccine remains unclear. Methods: We constructed a chimpanzee adenovirus-vectored TB vaccine candidate expressing Rv2299c (rAd-Rv2299c), and evaluated its immunogenicity and protective efficacy in murine models. Results: rAd-Rv2299c vaccine effectively induced a trained immunity phenotype in DCs, as evidenced by upregulated MHC-II and CD86 expression and increased pro-inflammatory cytokine (TNF-α, IL-6, IL-1β and IL-12p70) secretion. Moreover, its immunization promoted the generation of antigen-specific polyfunctional T cells, and robustly enhanced both Th1 and Th17-type immune responses. In a murine challenge model, vaccination significantly reduced bacterial loads in the lung and spleen and attenuated pulmonary inflammation, which was associated with robust recall T-cell immune responses. Conclusions: rAd-Rv2299c confers anti-TB protection by inducing trained immunity in DCs and promoting polyfunctional T-cell responses, thereby offering valuable experimental evidence and conceptual insights for the development of next-generation TB vaccines. Full article

Neoantigen-based immunotherapies harness somatic mutations as tumor-specific targets and represent a major advance in personalized cancer treatment. Since neoantigens are presented exclusively on cancer cells, they enable highly selective T-cell recognition with minimal off-tumor toxicity. Neoantigen vaccines are rapidly emerging as a versatile class of personalized cancer immunotherapies designed to prime tumor-specific T cells by targeting somatic mutations unique to each patient’s tumor. Multiple types of neoantigen vaccines, using peptide, mRNA, and DNA, have shown feasibility, safety, and immunogenicity across diverse solid tumors. Emerging comparative data indicate that the vaccines using peptide-pulsed dendritic cells (DCs) elicit higher per-epitope CD8⁺ T cell responses than mRNA-based vaccines, likely due to more efficient class I presentation of synthetic peptides and ex vivo-loaded DCs. In contrast, mRNAs, despite their capacity of targeting multiple neoantigen peptides simultaneously, often induce CD4⁺-dominant responses due to immunodominance patterns during antigen processing. Recent clinical trials in melanoma, glioblastoma, pancreatic cancer, and other types of cancer have demonstrated not only robust immune activation but also encouraging relapse-free outcomes when administered in adjuvant settings. Treatment timing strongly influenced immune responsiveness; patients with early-stage disease or those vaccinated after surgical resection generally exhibit more preserved systemic immunity and greater vaccine-induced T cell expansion compared to those with advanced disease. Future progress will rely on improved neoantigen prediction, including incorporation of post-translationally modified antigenic targets and acceleration of manufacturing pipelines to ensure timely, personalized vaccine delivery. Collectively, neoantigen vaccines offer substantial promise for integration into next-generation cancer treatment strategies. Full article

Background/Objectives: The current strategy for seasonal influenza prophylaxis relies on updating the vaccine components annually to account for the rapid antigenic drift of viruses and the low cross-protective efficacy of available vaccines. Mutant influenza viruses with truncated or deleted NS1 protein are known to stimulate cross-specific T-cell immune response and provide protection against heterosubtypic influenza A and B viruses. Methods: We generated NS1ΔC influenza A and B viruses with C-terminal NS1 deletions by reverse genetics. In a mouse model, we assessed the safety and immunogenicity of the B/Lee/NS1ΔC strain upon intranasal administration, as well as the mechanism of its cross-protective efficacy against sublethal B/Victoria and B/Yamagata challenges. We then investigated the potential of the intranasal Flu/NS1ΔC vaccine–a trivalent formulation of NS1ΔC A/H1N1, A/H3N2, and B influenza viruses–to protect mice from lethal influenza infection with homologous, heterologous, and antigenically drifted influenza A and B viruses. Results: Intranasal immunization with the B/Lee/NS1ΔC strain was safe in mice. It activated cross-specific T-cell responses in the lungs and protected animals against heterologous challenge by reducing viral load, inflammation, and lung pathology. Immunization with the trivalent Flu/NS1ΔC vaccine formulation improved survival and reduced weight loss and viral load upon challenge with A/H1N1pdm, A/H2N2, A/H5N1, and B/Victoria viruses. Conclusions: The trivalent intranasal Flu/NS1ΔC influenza vaccine is a promising tool to improve seasonal influenza protection and preparedness for an influenza pandemic. Full article

Acute myeloid leukemia (AML) is an aggressive cancer with rapid progression and a high relapse rate, highlighting the urgent need for effective treatments. While recent advances in drug therapies and combination regimens have improved outcomes, relapsed and refractory (R/R) AML still shows low response rates, poor prognosis, and limited survival. The lack of effective immunotherapies further complicates the management of R/R AML. The bone marrow tumor microenvironment (TME) poses a significant barrier, requiring multifaceted, combined therapeutic strategies for clinical success. This TME creates an immunosuppressive and metabolically challenging environment that limits the expansion, persistence, cytotoxicity, and survival of chimeric antigen receptor (CAR) T cells. Unlike CD19 in B-cell acute lymphoblastic leukemia (B-ALL), AML lacks a truly leukemia-specific antigen. Although clinical trials are ongoing, no CAR-T therapies have received FDA approval for AML. This paper explores the reasons behind these ongoing challenges. Full article

Background/Objectives: Notwithstanding the declaration by the World Health Organization in May 2023 regarding the conclusion of the COVID-19 pandemic, new cases of this potentially lethal infection continue to be documented globally, exerting a sustained influence on the worldwide economy and social structures. Contemporary SARS-CoV-2 variants, while associated with a reduced propensity for severe acute pathology, retain the capacity to induce long-term post-COVID syndrome, including in ambulatory patient populations. This clinical phenomenon may be attributable to potential autoimmune reactions hypothetically triggered by antiviral antibodies, thereby underscoring the need for developing novel, universal vaccines against COVID-19. The nucleocapsid protein (N), being one of its most conserved and highly immunogenic components of SARS-CoV-2, presents a promising target for such investigative efforts. However, the protective role of anti-N antibodies, generated during natural infection or through immunization with N-based vaccines, alongside the potential adverse effects associated with their production, remains to be fully elucidated. In the present study, we aim to identify potential sites of homology in structures or sequences between the SARS-CoV-2 N protein and human antigens detected using hyperimmune sera against N protein obtained from mice, rabbits, and hamsters. Methods: We employed Western blot analysis of lysates from human cell lines (MCF7, HEK293T, THP-1, CaCo2, Hep2, T98G, A549) coupled with mass spectrometric identification to assess the cross-reactivity of polyclonal and monoclonal antibodies generated against recombinant SARS-CoV-2 N protein with human self-antigens. Results: We showed that anti-N antibodies developed in mice and rabbits exhibit pronounced immunoreactivity towards specific components of the human proteome. In contrast, anti-N immunoglobulins from hamsters showed no non-specific cross-reactivity with either hamster or human proteomic extracts because of the lack of autoreactivity or immunogenicity differences. Subsequent mass spectrometric analysis of the immunoreactive bands identified principal autoantigenic targets, which were predominantly heat shock proteins (including HSP90-beta, HSP70, mitochondrial HSP60, and HSPA8), histones (H2B, H3.1–3), and key metabolic enzymes (G6PD, GP3, PKM, members of the 1st family of aldo-keto reductases). Conclusions: The results obtained herein highlight the differences in the development of anti-N humoral responses in humans and in the Syrian hamster model. These data provide a foundational basis for formulating clinical recommendations to predict possible autoimmune consequences in COVID-19 convalescents and are of critical importance for the rational design of future N protein-based, cross-protective vaccine candidates against novel coronavirus infections. Full article

Background: Being central players in the adaptive immunity, the study of T-cell responses is crucial in both natural infections and vaccine-induced immunity. In this study, we assessed the antigen-specific T-cell responses to dengue virus (DENV) to identify the most immunogenic antigen for evaluating dengue-specific T-cell responses. Methods: Patients with dengue disease and subjects vaccinated with the QDENGA (TAK-003) vaccine (before and three months after vaccination) were enrolled. The T-cell-specific response was measured by ELISPOT and Activation Induced Markers (AIM) assay following PBMC stimulation either with DENV1-4 CD4 and CD8 MegaPools (MP) or serotype-specific DENV peptide pools at different concentrations. Results: We found that both DENV1-4 CD4 MP (at 1 µg/mL) and CD8 MP (at 5 µg/mL), which encompass all four DENV serotypes, elicited specific T-cell responses in patients with dengue infection independent of the infecting serotype. In contrast, selected serotype-specific DENV peptide pools have a lower ability to induce a measurable T-cell response. Moreover, DENV1-4 CD4 and CD8 MPs, at the highest concentrations, are suitable candidates to evaluate the dengue-specific T-cell response in vaccinated subjects. Conclusions: These findings support the use of the MP approach to investigate dengue-specific T-cell response to monitor the response during the infection and after vaccine administration. Full article

Klebsiella pneumoniae (K. pneumoniae) is an opportunistic bacteria that can result in severe liver abscesses, pulmonary damage, and potentially fatal outcomes. Research has demonstrated that the outer membrane vesicles (OMVs) released by it can provide significant protection to infected animals and may serve as a promising candidate antigen for the development of a novel vaccine. Nevertheless, the specific mechanisms through which OMVs mitigate the detrimental effects of K. pneumoniae infection by promoting the polarization pathways of macrophages and T helper cells (Th cells) remain poorly understood. In this study, we first confirmed that Klebsiella pneumoniae outer membrane vesicles (K. pneumoniae_OMVs) were protective in K. pneumoniae-infected mice, and then we investigated the protective mechanisms by transcriptome data analysis. Then, we constructed a model of in vitro macrophage polarization, an in vivo model for Th differentiation, and a K. pneumoniae infection model in K. pneumoniae_OMVs-immunized mice. qRT-PCR, IHC, Western blotting, and ELISA were used to confirm the polarization indicators. The results showed that K. pneumoniae_OMVs were able to provide specific protection for mice with a maximum protection rate of 80%. In addition, the results of a transcriptome analysis suggested that the protective mechanism might be related to Th cells and macrophage polarization. Mice immunized with K. pneumoniae_OMVs were able to achieve rapid bacterial clearance after K. pneumoniae infection through an M1/Th1 immune response. Subsequently, tissue repair was accomplished through Th2/M2 immune response in the late stage of K. pneumoniae infection to avoid causing inflammatory damage. This study offers a theoretical foundation for the K. pneumoniae_OMVs vaccine’s actual application. Full article