Search Results (300)

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 Zika virus (ZIKV) represents an ongoing threat to public health due to its neurological and congenital complications. Even after 10 years since the first major outbreak, correlated with an increase in congenital ZIKV syndrome, there is still no vaccine or treatment for this infection. Among the various existing platforms, DNA vaccines combined with the use of immunoinformatics tools allow for the efficient selection of immunogenic epitopes and immunostimulatory molecules with greater flexibility, in addition to being simple to manufacture and having a higher cost–benefit ratio in production. Methods: In this work, we conducted an integrated approach, combining in silico analyses and in vivo experimental validations, for the development of multi-epitope DNA vaccines against ZIKV. The computational analyses confirmed structural stability, adequate solubility, absence of toxicity, and immune induction potential for constructs based on epitopes from the Envelope (E) and NS1 proteins. Therefore, we evaluated DNA constructs containing the ENV + NS1 epitopes, both with and without fusion to the ssPGIP signal peptide, in BALB/c mice. Results: Both vaccines increased the population of CD4⁺ and CD8⁺ T lymphocytes, in addition to the production of IgG antibodies associated with the Th1 profile. The fusion with ssPGIP broadened the response, stimulating the release of Th1, Th2, and Th17 cytokines, as well as enhancing antibody formation. In contrast, its absence was associated with a slight increase in CD4⁺ and CD8⁺ T cells, accompanied by restricted cytokine production. Conclusions: These results indicate that epitope-targeted techniques offer a viable and safe method for inducing robust immune responses, demonstrating that combining immunoinformatics methods with early preclinical testing is an effective strategy for ZIKV vaccine development. Furthermore, although the present study focused on initial immunogenic characterization, future studies involving viral challenge in a suitable animal model will be essential to conclusively determine the protective efficacy of these vaccine candidates. Full article

Background: Individual differences in immune responses to African swine fever virus (ASFV), whether induced by vaccination or natural infection, may be linked to genetic variation in the genes involved in antigen presentation. Methods: A total of nine pigs from the 112-population were selected for RNA-seq analysis. To pinpoint key transcription factors (TFs) regulating gene expression in the lymph nodes, weighted Kendall’s Tau rank correlation analysis was performed to link the TF binding potential with the extent of differential expression of target genes. Results: CD8⁺ T cells expressing a specific epitope of the ASFV p72 protein (ACD8⁺) accounted for 41% of the total CD8⁺ T cells in peripheral blood. A total of 2062 transcripts were identified as differentially expressed across the nine pigs (q-value < 1 × 10⁻⁸). Differential expression levels of the target genes for MECP2, ETS1, ZBTB33, ELK4, and E2F4 were significantly correlated with their TF binding potential (p < 0.05). Six SNPs were identified in the promoter region of ELK4. Analysis of the 112-pig population revealed that SNPs at S.-404A>G and S.-668C>T loci were significantly associated with ACD8⁺ levels (q-value < 0.01). Individuals with the AA genotype at S.-404A>G had significantly higher ACD8⁺ counts compared to those with AG and GG genotypes (q-value < 0.05). At the S.-668C>T locus, ACD8⁺ levels were highest in the CC genotype, followed by CT and TT genotypes, with CC showing notably higher ACD8⁺ counts (q-value < 0.05). Notably, the S.-404A>G site overlaps with potential binding sites for TFs FOXA2, GATAs, and TRPS1, while the S.-668C>T site lies within the binding regions for NR1H3, RARA, VDR, and NR1I3. Conclusion: These mutations may disrupt TFs binding to the ELK4 promoter, potentially reducing ELK4 expression and impairing antigen processing and presentation. Full article

Background: Accumulating evidence regarding the association between tumor-infiltrating lymphocyte (TIL) subtypes and prognosis in colorectal cancer has emerged recently in the literature. Whether the prognostic impact of TIL subsets is different according to tumor location remains unknown, despite genetic, epigenetic and molecular differences between the proximal and distal colon. Our study aimed to investigate the value of CD3⁺ lymphocytes, reflecting overall T-cell infiltration, CD8⁺ cells identifying cytotoxic effector T-cells and CD73⁺ cells acting as a modulator of immunosuppression, stratified by primary tumor location. Methods: The density of CD73⁺, CD3⁺ and CD8⁺ tumor-infiltrating B- and T-cells was determined in colon cancer patients using whole-section tissue sampling, heat-induced epitope retrieval, primary antibodies and DAB visualization. QuPath Cell counter function quantified nucleated cells and immune-positive percentages; ImageJ assessed staining intensity via color deconvolution and optical density. An Immunoreactive Score combined intensity and positivity for immune profiling. The Receiver Operating Characteristic (ROC) curve analysis was used to determine the optimal cut-off values for CD3⁺, CD8⁺ and CD73⁺ lymphocytes. Statistical analysis was performed in order to identify potential associations between TILs expression and pathological characteristics, according to the location of the primary tumor. Survival analysis was carried out using the Kaplan–Meier method. Results: A total of 100 patients were included in the study. CD3⁺ T-cells were the most abundantly expressed and were more predominantly encountered in the right colon. Total CD3⁺ numbers were correlated with T stage and the presence of perineural invasion in left-sided tumors, as well as with tumor grading in the right colon. Correlation analysis based on CD3⁺ threshold values according to tumor location demonstrated a statistically significant association between a higher N stage and low CD3⁺ cell values (p value = 0.0306), and higher perineural invasion and low CD3⁺ TILs values in the left colon (p value = 0.0123). In addition, low CD8⁺ values were associated with a higher T stage in the left colon (p value = 0.0382). Survival analysis did not demonstrate statistically significant differences between the investigated groups. Conclusions: TIL subtypes in colon cancer patients demonstrate significant variability according to the location of the primary tumor and are associated with different clinical and pathological characteristics. This exploratory study requires larger validation before TIL densities can guide therapy. Full article

Background/Objectives: T cell bispecific antibodies (TCBs) result in the activation of T cell receptor signaling upon binding to tumor antigens providing signal 1 to T cells. To enhance and sustain their activity, a co-stimulatory signal 2 is required. Here CEACAM5-targeted 4-1BBL antibody fusion proteins for combination with CEA-TCB (cibisatamab, RG7802) are described in an investigation of the relationship between the CEACAM5 epitope and T cell activity. Methods: CEACAM5-targeted bispecific 4-1BBL antibody fusion proteins (CEA-4-1BBLs) were generated based on different CEACAM5 antibodies and characterized in vitro in Jurkat-4-1BB reporter and PBMC cell assays. The impact of shed CEA on in vitro activity and cynomolgus cross-reactivity was studied. In vivo efficacy was assessed in human stem cell humanized NSG mice xenograft models bearing MKN-45 and HPAFII tumors. Results: MFE23-4-1BBL and Sm9b-4-1BBL showed superior functional activity in Jurkat-4-1BB reporter and primary T cell assays when combined with the CD3 antibody V9, whereas T84.66-LCHA-4-1BBL and A5B7-4-1BBL performed better when combined with CEA-TCB. In humanized NSG mice MKN-45 and HPAFII xenograft models, T84.66-LCHA-4-1BBL mediated the best anti-tumor efficacy. Conclusions: For the assessment of the combination of CEA-TCB with CEA-4-1BBL, co-stimulatory antibody fusion protein in vitro assays are not sufficient to fully capture the complex relationships affecting efficacy. Thus, screening with different cell assays and in vivo efficacy studies in combination with CEA-TCB are essential to select the best candidate. Based on the totality of data on the T84.66-LCHA-4-1BBL antibody fusion protein comprising the CEACAM5 antibody, T84.66-LCHA was selected as the optimal combination partner for CEA-TCB. Full article

Background: Understanding the immune mechanisms that differentiate protective from pathogenic responses during dengue virus (DENV) infection is critical for effective vaccine development. Objective: To investigate how CD4⁺ T cell depletion alters viral control and the humoral immune response during primary DENV2 infection in a non-human primate (NHP) model. Methods: Rhesus macaques were depleted of CD4⁺ T cells prior to DENV2 infection. Viral kinetics, B cell activation, antibody specificity, and functional outcomes were evaluated longitudinally, including cross-reactivity and antibody-dependent enhancement (ADE) potential. Results: CD4⁺ T cells were essential for early viral clearance and the generation of robust, type-specific neutralizing antibodies. In their absence, animals exhibited early non-specific polyclonal B cell activation, delayed isotype switching, and an expanded repertoire of cross-reactive antibodies to DENV and Zika virus (ZIKV), with diminished neutralizing capacity. CD4-depleted macaques also showed increased ADE potential, particularly against ZIKV, and elevated anti-NS1 IgG titers that persisted one-year post-infection. Conclusion: CD4⁺ T cells play a critical role in orchestrating effective, durable, and type-specific antibody responses during primary DENV infection. Their absence leads to delayed antibody maturation, greater cross-reactivity, and higher ADE potential. These findings emphasize the need for DENV and ZIKV vaccines to include CD4⁺ T cell epitopes that promote high-quality, type-specific antibody responses and minimize ADE risk. Full article

Treatment paradigms for B-cell lymphomas have evolved significantly in the last decades. Nevertheless, the widespread clinical use of immunotherapy has demonstrated that it invariably leads to the development of resistance. This review outlines the underlying molecular mechanisms of resistance associated with emerging immunotherapeutic strategies, including Chimeric Antigen Receptor (CAR) T cell therapy and bispecific antibodies (BsAbs). In high-grade B-cell lymphomas, nearly 50% of patients progress following CAR T treatment due to host-related factors affecting CAR T cell proliferation and persistence, as well as tumor-intrinsic factors, such as loss of CD19 epitope expression, trogocytosis, and other genomic alterations (e.g., CD19 mutations, chromothripsis, APOBEC mutational activity, and deletions of RHOA). Additional genomic and epigenetic events, including mutations, alternative splicing of CD19, and aberrant promoter methylation, further contribute to resistance. BsAbs, representing an off-the-shelf T-cell-redirecting strategy, have recently shown promising single-agent efficacy with a manageable toxicity profile, predominantly characterized by T cell overactivation syndromes. Similarly to CAR T cell therapy, BsAb resistance arises through diverse mechanisms, such as antigen loss, T cell dysfunction (exhaustion and regulatory T cell activation), tumor-intrinsic alterations (e.g., TP53 mutations and MYC amplifications), and immunosuppressive influences from the tumor microenvironment. These findings underscore the complexity of immune evasion in B-cell lymphomas and highlight the ongoing need to optimize immunotherapeutic strategies and develop combination approaches to overcome resistance. Full article

The novel data show that the Hsp70 protein is a potent activator of the immune system. Using limited trypsinolisis, we have identified the epitopes of Hsp70 responsible for TREM-1-dependent and TREM-1-independent cytotoxicity. The 11aa N9 peptide (AMTKDNNLLGR) contains nine amino acids that correspond to the amino acid sequence of the known TKD peptide. Also, like TKD, this peptide does not interact with the TREM-1 receptor but activates CD94+ NK cells that kill tumor cells by secreting granzymes and inducing apoptosis. The 16aa peptide N7 (SDNQPGVLIQVYEGEK) interacts with the TREM-1 receptor and induces the activation of NK cells and cytotoxic T lymphocytes at different time points. T-lymphocytes activated by this peptide induce two alternative processes of cell death in HLA-negative tumor cells, apoptosis and necroptosis, through the interaction of the FasL lymphocyte with the Fas receptor of the tumor cell. A shortened fragment of this peptide, N7.1 (SDNQPGVL), has been identified that inhibits the interaction of TREM-1 with its ligands. This peptide has shown protective effects in the development of sepsis in mice. The results obtained can be used in antitumor and anti-inflammation therapy. Full article

Human Leukocyte Antigen (HLA) Class II (HLA-II) molecules bind peptides of phagocytosed non-self proteins and present them on the cell surface to circulating CD4+ T lymphocytes. A successful binding of the presented peptide with the T cell receptor (TCR) activates the CD4+ T cell, leading to the production of antibodies against the peptide (and the protein of its origin) by the B cell and augmentation of the cytotoxic and memory functions of CD8+ T cells. The first and essential step in this process is the successful formation of a stable peptide-HLA-II complex (pHLA-II), which is achieved when the peptide binds with high affinity to the HLA-II molecule. Such highly antigenic non-self peptides occur in melanoma-associated proteins and could be used as antitumor agents when bound to a matching HLA-II molecule. The objective of this study was to identify such peptides from 15 melanoma-associated proteins. We determined in silico the predicted binding affinity (IC₅₀) of all pHLA-II pairs between 192 common HLA-II molecules and all possible linear 15-amino acid (15-mer) peptides (epitopes) of 15 known melanoma-associated antigens (N = 3466 epitopes) for a total of 192 × 3466 = 665,472 determinations. From this set, we identified epitopes with strong antigenicity (predicted best binding affinity [PBBA] IC₅₀ < 50 nM). Of a total of 665,472 pHLA-II tested, 5941 (0.89%) showed strong PBBA, stemming from 117 HLA-II alleles and 679 distinct epitopes. This set of 5941 pHLA-II pairs with predicted high antigenicity possesses the requisite information for devising multipeptide vaccines with those epitopes alone or in combination with the corresponding HLA-II molecules. The results obtained have a major implication for cancer therapy, namely that the administration of subsets of the 679 high antigenicity epitopes above, alone or in combination with their associated HLA-II molecules, would be successful in engaging CD4+ T helper lymphocytes to augment the cytotoxic action and memory of CD8+ T lymphocytes and induce the production of antitumor antibodies by B cells. This therapy would be effective in other solid tumors (in addition to melanoma) and would be enhanced by concomitant immunotherapy with immune checkpoint inhibitors. Full article

Background: CLEC5A is a C-type lectin expressed by monocytes and neutrophils, playing an important role in innate immunity. Although it has been shown to interact with the spike protein of SARS-CoV-2, its role during vaccination remains poorly understood. Methods: To address this question, we combined in vitro assays to characterize CLEC5A and spike expression and their impact on monocyte differentiation and T-cell activation; in vivo studies to evaluate CLEC5A expression, immune responses, and vaccine efficacy in a murine model; and in silico analyses to identify potential spike epitopes and CLEC5A interaction sites. Results: The Pfizer-BioNTech bivalent mRNA vaccine induced spike expression and CLEC5A upregulation in THP-1 monocytes, promoting M1-like differentiation and CD86⁺ activation. In PBMC co-cultures, CLEC5A⁺ monocytes acted as antigen-presenting cells, releasing inflammatory chemokines and activating both CD4⁺ and CD8⁺ T cells, thereby linking CLEC5A expression to adaptive immunity. In mice, CLEC5A expression was observed on inflammatory monocytes (CCR2⁺CX3CR1^low) within two days of vaccination. In vivo, CLEC5A expression increased during SARS-CoV-2 infection and after immunization, but declined following viral challenge in vaccinated animals. Consistently, robust humoral and cellular responses were detected post-immunization. In silico analysis further suggested differential CLEC5A binding across B- and T-cell epitopes within the spike glycoprotein. Conclusions: These findings suggest that CLEC5A may play a role in bridging innate and adaptive immune responses during SARS-CoV-2 vaccination. Although further studies with different vaccine platforms are necessary to confirm and expand these observations, our results provide preliminary evidence supporting the potential of CLEC5A as an exploratory biomarker of vaccine-induced immunity. Full article

This study investigated the role of molecular mimicry in the context of autoimmunity associated with viral infection, using SARS-CoV-2 as a model system. A bioinformatic analysis was performed to identify sequence homologies between the SARS-CoV-2 Spike (S) protein and the human proteome, with a specific focus on immunogenic regions to assess potential cross-reactivity. The analysis revealed homologous regions between the viral S protein and several human proteins, including DAAM2, CHL1, HAVR2/TIM3, FSTL1, FHOD3, MYO18A, EMILIN3, LAMP1, and αENaC, which are predicted to be recognizable by B-cell receptors. Such recognition could potentially lead to the production of autoreactive antibodies, which can contribute to the development of autoimmune diseases. Furthermore, the study examined potential autoreactive CD4+ T-cell responses to human protein autoepitopes that could be presented by HLA class II molecules. Several HLA class II genetic variants were computationally associated with a higher likelihood of cross-reactive immune reactions following COVID-19, including HLA-DPA1*01:03/DPB1*02:01, HLA-DPA1*02:01/DPB1*01:01, HLA-DPA1*02:01/DPB1*05:01, HLA-DPA1*02:01/DPB1*14:01, HLA-DQA1*01:02/DQB1*06:02, HLA-DRB1*04:01, HLA-DRB1*04:05, HLA-DRB1*07:01, and HLA-DRB1*15:01. Additionally, seven T helper cell autoepitopes (YSEILDKYFKNFDNG, ERTRFQTLLNELDRS, AERTRFQTLLNELDR, RERKVEAEVQAIQEQ, NAINIGLTVLPPPRT, PQSAVYSTGSNGILL, TIRIGIYIGAGICAG) were identified that could be implicated in autoimmune T-cell responses through presentation by class II HLA molecules. These findings highlight the utility of viral B- and T-cell epitope prediction for investigating molecular mimicry as a possible mechanism in virus-associated autoimmunity. Full article

CD19-targeted therapies, including monoclonal antibodies, antibody–drug conjugates, and chimeric antigen receptor (CAR) T-cell products, have significantly improved outcomes in relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). Despite their clinical efficacy, resistance and antigen modulation pose substantial challenges, especially in patients requiring sequential therapy. This review provides a comprehensive overview of CD19 biology and its relevance as a therapeutic target. We examine mechanisms of resistance such as antigen loss, epitope masking, and T-cell exhaustion, as well as the implications of tumor microenvironmental immunosuppression. Future efforts should prioritize the integration of real-time diagnostics, such as flow cytometry, immunohistochemistry, and transcriptomic profiling, and AI-assisted predictive models to optimize therapeutic sequencing and expand access to personalized immunotherapy. Full article

A novel skin test for an in vivo assessment of SARS-CoV-2-specific T-cell immunity was developed using CoronaDermPS, a multiepitope recombinant polypeptide encompassing MHC II–binding CD4+ T-cell epitopes of the SARS-CoV-2 structural proteins (S, E, M) and full length nucleocapsid (N). In silico epitope prediction and modeling guided antigen design, which was expressed in Escherichia coli, was purified (>95% purity) and formulated for intradermal administration. Preclinical evaluation in guinea pigs, mice, and rhesus macaques demonstrated a robust delayed type hypersensitivity (DTH) response at optimal doses (10–75 µg), with no acute or chronic toxicity, mutagenicity, or adverse effects on reproductive organs. An integrated clinical analysis included 374 volunteers stratified by vaccination status (EpiVacCorona, Gam-COVID-Vac, CoviVac) prior to COVID-19 infection (Wuhan/Alpha, Delta, Omicron variants), and SARS-CoV-2–naïve controls. Safety assessments across phase I–II trials recorded 477 adverse events, of which >88% were mild and self-limiting; no severe or anaphylactic reactions occurred. DTH responses were measured at 24 h, 72 h, and 144 h post-injection by papule and hyperemia measurements. Overall, 282/374 participants (75.4%) exhibited a positive skin test. Receiver operating characteristic analysis yielded an overall AUC of 0.825 (95% CI: 0.726–0.924), sensitivity 79.5% (95% CI: 75.1–83.3%), and specificity 85.5% (95% CI: 81.8–88.7%), with comparable diagnostic accuracy across vaccine, and variant subgroups (AUC range 0.782–0.870). CoronaDerm-PS–based skin testing offers a simple, reproducible, and low-cost method for qualitative evaluation of T-cell–mediated immunity to SARS-CoV-2, independent of specialized laboratory equipment (Eurasian Patent No. 047119). Its high safety profile and consistent performance across diverse cohorts support its utility for mass screening and monitoring of cellular immune protection following infection or vaccination. Full article

Regulatory T (Treg) cells are essential for maintaining self-tolerance and regulating immune responses. In this study, we report the identification of Treg cell epitopes in human α-tubulin that were capable of enhancing IL-10-producing Foxp3⁺ Treg cells and LAG-3⁺CD49b⁺FoxP3⁻ Tr1 cells in vitro, using human peripheral blood mononuclear cells. Similarly, we also demonstrate that a peptide pool containing the identified Treg cell epitopes (αTBL pool) suppressed the T cell responses elicited by HLA class I- and class II-restricted T cell epitopes. Moreover, stimulation of naive CD4⁺ T cells with autologous monocyte-derived dendritic cells in the presence of the αTBL pool promoted the differentiation of functional FoxP3⁺ Treg cells, which suppressed the proliferation of CD3/CD28-activated T cells. Finally, we show that one of the identified epitopes, identical between human and mouse, also stimulated FoxP3⁺ Treg cells in splenocytes isolated from C57BL/6 mice. Considering the elevated expression of α-tubulin in all cell types, the presence of Treg cell epitopes in this protein may facilitate a broad mechanism of immune regulation. Moreover, α-tubulin Treg cell epitopes may prove useful in creating novel treatments for conditions marked by excessive or misdirected immune responses. Full article

The development of vaccines against many infectious diseases has been a great success of medical science over the last century. However, despite numerous efforts, effective vaccines for herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) remain elusive. Since 1920s, a range of therapeutic vaccine candidates, primarily focusing on neutralizing antibodies, have failed to confer robust and durable protective immunity against recurrent herpes. Recent advances in omics, artificial intelligence, and deep learning have opened new horizons for the rational design of tissue-targeted herpes vaccine strategies for inducing potent and durable HSV-specific CD4⁺ and CD8⁺ T_RM cell immunity at both the sensory ganglia (central immunity), the site of latency/reactivation cycle, and the mucocutaneous epithelial tissues (peripheral immunity), the site of viral replication that causes herpetic lesions. Prime/Pull/Keep ocular and genital herpes vaccine candidates (PPK vaccines) have recently shown success in pre-clinical animal model trials of recurrent ocular and genital herpes. These PPK vaccines used “asymptomatic” epitopes/antigens to prime CD4⁺ and CD8⁺ T cells (Prime); primed T cells are then pulled towards the infected central and peripheral epithelial tissues using T cell-attracting chemokines, such as CXCL11 (Pull), followed by survival cytokines (IL-2, IL-7 and/or IL-15) or mucosal chemokines (CXCL17 and/or CCL28) to maintain the “pulled” tissue-resident T cells longer within infected tissues (Keep). We discuss recent efforts in designing a clinically adapted, all-in-one PPK mucosal therapeutic vaccine that would require a single administration to sequentially trigger all three PPK steps of priming, recruiting, and maintaining antiviral, tissue-resident, protective T cells at the primary sites of viral entry and latency. Full article