The clinical utility of streptokinase, a widely used and cost-effective thrombolytic agent, has gained importance post COVID-19 due to increase in cardiovascular diseases globally. But the strong humoral immunogenicity exhibited by it, restricts its usage. Building upon our prior work of developing truncated streptokinase variants and their plasminogen activation study, we report here the results of immunogenicity studies for identification of variants with reduced immunogenicity. A panel of ten rationally truncated and recombinantly expressed streptokinase fragments were screened for antibody recognition and immunogenicity potential. Out of the ten fragments, two N-terminal constructs (amino acid residues 1-300 and 1-173) exhibited approximately 40-45% lower ELISA immunoreactivity compared with full-length streptokinase during initial in vitro screening. These fragments were also already reported to retain >85% of native plasminogen activation activity. In vivo evaluation of the fragments in rabbits demonstrated significantly attenuated humoral responses over a 28-day immunization period, confirmed by longitudinal antibody titration and cumulative area-under-the-curve analysis when compared to the full-length streptokinase. Fragment 1-173 emerged as a promising lower-immunogenic thrombolytic candidate, and this work demonstrates that rational domain minimization can decouple functional competence from immunodominant regions in streptokinase establishing a broadly applicable framework for engineering improved therapeutic proteins.

Human leukocyte antigen (HLA)-G is an immunosuppressive molecule involved in inflammation and has been reported to be induced by viral infections. Although the upper airway is a major entry site for viral pathogens, the expression of HLA-G in the nasal mucosa and its regulatory mechanisms remain unclear. We investigated HLA-G expression in primary human nasal epithelial cells (HNECs) and whether it is regulated by Toll-like receptor (TLR) stimulation. HNECs were stimulated with TLR1-9 agonists. HLA-G mRNA expression was quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR), and HLA-G protein expression was assessed by Western blotting. HLA-G mRNA was detected in unstimulated HNECs. Among the TLR agonists tested, TLR3 (polyinosinic-polycytidylic acid [Poly(I:C)]) stimulation significantly upregulated HLA-G mRNA expression (2.85-fold, 95% confidence interval 1.98-4.10). HLA-G mRNA expression increased with Poly(I:C) concentration, with significant upregulation at 1 and 10 μg/mL and a significant dose-response trend. At 10 μg/mL, mRNA expression was significantly upregulated from 16 h onward. Western blotting revealed that Poly(I:C) stimulation significantly upregulated HLA-G protein expression. These findings demonstrate HLA-G expression in HNECs and its upregulation by Poly(I:C), suggesting that HLA-G may be regulated in response to dsRNA-triggered innate immune signaling in the nasal epithelium.

Adults with type 2 diabetes mellitus (T2DM) are at increased risk of invasive pneumococcal disease due to impaired immune function; however, data on vaccine-induced immunity in this population remain limited. This study evaluated the immunogenicity of sequential pneumococcal vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) followed by the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in Indian adults with T2DM. A total of 132 participants were enrolled, and serotype-specific IgG concentrations were measured before vaccination and eight weeks after PPSV23 administration. At baseline, over 70% of participants had IgG concentrations ≥1.3 μg/mL for serotypes 8, 9 N, 14, 15B, 19 A, 20, and 33F, while serotypes 3, 12F, 5, 4, and 17F had protective antibody levels in fewer than 50% of participants. Post-vaccination, IgG concentrations increased significantly for most serotypes. Serotype 14 demonstrated the highest geometric mean concentration (80.79 μg/mL), followed by serotypes 15B and 6B, while serotype 3 showed the lowest IgG concentration (0.94 μg/mL). Geometric mean fold rise ranged from 2.47 for serotype 3 to 54.61 for serotype 6B, with stronger responses in younger adults (35-54 years). Sequential pneumococcal vaccination was associated with increased serotype-specific IgG concentrations in adults with type 2 diabetes, demonstrating measurable serological immunogenicity.

Granulomatosis with polyangiitis (GPA) is a rare, complex autoimmune vasculitis. Investigating the differential mRNA expression signature in PBMCs may identify critical gene(s) implicated in GPA. This study recruited 21 GPA patients and 23 healthy controls of North Indian origin. Whole mRNA was isolated from PBMCs, and whole mRNA sequencing was performed on the discovery cohort to identify differentially expressed genes (DEGs). Pathway enrichment and protein-protein interaction analyses were performed. Hub genes were identified, and prioritized DEGs were validated using qRT-PCR in the replication cohort. DEGs were compared with expression studies on GPA available on the Gene Expression Omnibus (GEO) database. We obtained 5757 downregulated and 46 upregulated genes (adj-p < 0.05; log2FC ≥ 2/≤-2), which predicted 25 hub genes that were found to be enriched in IL-17-CXCR-TNF mediated proinflammatory pathways. Two critical hub genes RHOA (log2FC = 0.65,95%CI = 0.18 to 1.12; p = 0.02) and CDH1 (log2FC = -0.85, 95%CI = -1.47 to -0.23; p = 0.04) were significantly replicated in the replication cohort. Another proinflammatory hub gene LCN2 (log2FC = 2.15; p = 6.5E-04), was found as a shared upregulated gene in CD4[+], CD8[+], and CD4[+]CD8[+] double-positive T-cells in GPA patients. The present study reported the significant differential expression of the RHOA and CDH1 in GPA. IL-17 downstream proinflammatory pathways were identified as critical for the GPA.

Development of proficiency testing (PT) for ABO genotyping is of great importance for the purpose of standardization and quality control in transplantation and histocompatibility laboratories. Hod-Dvorai et al. offer an interesting experience, describing a graded PT scheme that was developed and realized within a few years. The use of independently characterized materials for selected surveys may allow distinguishing between analytical errors and methodological trends, while the increase of allele diversity would contribute to the relevance of PT. These changes might improve the precision of grading and, indeed, participants feedback, thus further developing the framework suggested by the authors of the article.

Preeclampsia (PE) is linked to placental dysplasia and autophagy disorder. Atg7 is vital for placental development, yet its rs1375206 polymorphism with PE risk in Chinese Han population remains unclear. This study enrolled 990 PE patients and 1004 controls to genotype Atg7 rs1375206. Results revealed that this genetic variant was associated with susceptibility to preeclampsia (PE). Under the dominant genetic model (GG versus CG + CC, OR = 0.76, 95% CI 0.63-0.91, P = 0.003), carriers of the GG genotype exhibited lower PE risk compared with individuals carrying at least one C allele. Allelic comparison further verified that the C allele increased disease susceptibility compared with the G allele (OR = 1.33, 95% CI 1.17-1.51, P < 0.001). The recessive model (CC versus CG + GG, OR = 1.64; 95% CI, 1.29-2.07; P < 0.001) additionally confirmed a higher disease risk among CC homozygotes. The codominant comparison (CC vs CG vs GG) showed no significant difference in PE risk between CG heterozygotes and GG homozygotes (P = 0.102), whereas CC homozygotes exhibited substantially elevated risk relative to both CG heterozygotes and GG homozygotes (CC vs CG: OR = 1.52, 95% CI 1.19-1.95, P < 0.001; CC vs GG: OR = 1.79, 95% CI 1.39-2.32, P < 0.001). Stratified analysis showed differences in PE severity and onset subgroups. Bioinformatics and IHC confirmed reduced Atg7 expression in PE placentas. Atg7 rs1375206 may be associated with PE risk and serve as a potential genetic marker.

Hepatitis C virus (HCV) remains a major global health burden, and its core protein is central to both viral replication and immune evasion. Here, we used an immunoinformatics approach to design a multiepitope vaccine directed against the HCV core protein. Several prediction platforms were applied to identify immunogenic regions that were antigenic, non-toxic, and non-allergenic; the twenty epitopes that met all of these criteria were joined by linkers and fused to 50S ribosomal protein L7/L12 and Pam2Cys adjuvants. The resulting construct was modeled, refined, and docked with Toll-like receptors (TLR2, TLR3, TLR4, TLR7, and TLR9), after which normal mode analysis (NMA) and molecular dynamics (MD) simulations were performed to assess its stability. The refined fusion protein showed favorable predicted binding to all of the receptors tested, and both NMA and MD indicated that the vaccine-TLR2 complex was conformationally stable. Immune simulation further predicted the production of anti-HCV antibodies and the activation of cellular immunity. Taken together, these findings identify the construct as a promising HCV vaccine candidate that now warrants experimental validation.

Human leukocyte antigen-G (HLA-G) is a nonclassical major histocompatibility complex (MHC) class Ib molecule that plays a critical role in immune tolerance, primarily by promoting immune escape and inducing T-cell anergy. Early studies of HLA-G focused mainly on its function during pregnancy, where it is essential for maintaining maternal-fetal tolerance. In recent years, accumulating evidence has revealed the broader immunoregulatory functions and mechanisms of HLA-G in a variety of pathological conditions. As a key immunosuppressive molecule, HLA-G has been extensively investigated in the context of organ transplantation. In this review, we summarize the current understanding of the biological functions of HLA-G, with particular emphasis on its genetic polymorphisms, and discuss their immunomodulatory roles in renal allograft rejection and post-transplant infections.

Messenger RNA vaccines have demonstrated extraordinary success during the COVID-19 pandemic, yet conventional mRNA platforms exhibit inherent limitations including modest molecular stability, stringent cold-chain requirements, waning antibody responses, and the necessity for relatively high doses to achieve protective immunity. Next-generation RNA technologies-specifically self-amplifying RNA (saRNA) and circular RNA (circRNA) vaccines-address these shortcomings through fundamentally distinct molecular designs that enhance antigen expression kinetics and prolong immunological persistence. Self-amplifying RNA vaccines incorporate viral replicase elements derived from alphaviruses, enabling intracellular amplification of the antigen-encoding sequence and sustained protein production at doses substantially lower than conventional mRNA. Circular RNA vaccines feature covalently closed loop structures that confer complete resistance to exonuclease-mediated degradation, extending translational half-life and maintaining antigen presentation over extended periods. This review provides a comprehensive examination of the molecular architecture, intracellular processing mechanisms, and immune activation pathways characteristic of both platforms. We critically evaluate formulation and delivery strategies, with particular emphasis on lipid nanoparticles and emerging carrier systems, and assess manufacturing challenges related to scalability, purity, and quality control. The preclinical and early clinical evidence supporting both platforms is synthesized and compared, highlighting the dose-sparing capacity of self-amplifying RNA and the exceptional durability of circular RNA-induced responses. Persistent obstacles-including reactogenicity modulation, circularization efficiency, replicase-associated innate suppression, and regulatory standardization-are analyzed in depth. We conclude by identifying priority research directions essential for clinical translation, including optimized delivery systems, refined safety profiling, and cold-chain-independent formulations that will enable global vaccine accessibility.

Endoplasmic reticulum aminopeptidase 2 (ERAP2) trims endogenous peptides before loading onto Human leukocyte antigen (HLA) class I molecules. A common polymorphism in ERAP2 (rs2248374) causes nonsense-mediated decay of ERAP2 mRNA, resulting in loss of protein expression. This polymorphism is associated with several HLA class I-associated inflammatory diseases including psoriasis. This study aimed to determine whether this specific polymorphism is sufficient to drive measurable differences in HLA-C expression and HLA class I immunopeptidome in primary human epidermal keratinocytes (HEKs). HEKs from 34 healthy donors were genotyped for ERAP2 (rs2248374) and HLA-C (rs4406273). HLA-C expression was assessed by flow cytometry. The immunopeptidome was isolated by immunoaffinity purification and analysed by liquid chromatography-mass spectrometry. HLA-C expression and global immunopeptidome features, including peptide yield, length distribution, and amino acid composition, were comparable across ERAP2 genotypes. However, ERAP2 genotype was associated with differences in peptide repertoire with the presence of genotype-specific peptides, an effect that became more pronounced in HLA-C*06:02-positive donors and even more among predicted HLA-C*06:02 majority-voted binder peptides. Within this HLA-C*06:02-stratified context, distinct sequence and chemical composition at the P1 anchor position also emerged. This suggests that the impact of ERAP2 is strongly context-dependent and partially masked in heterogeneous HLA settings.

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the genus Leishmania. Currently, no licensed human vaccine is available and increasing drug resistance continues to compromise the disease control. The present study aimed to computationally design and evaluate a multi-epitope vaccine candidate targeting the conserved amastin protein of Leishmania donovani (UniProt ID: A5XDA6) using an integrated immunoinformatics approach. Cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL) and B cell epitopes were predicted and sequentially prioritized on the basis of HLA-binding affinity, antigenicity, allergenicity and molecular docking with their respective HLA molecules. A total of twelve epitopes (five CTL, four HTL and three B cell epitopes) were selected. Conservancy analysis demonstrated that most epitopes were highly conserved across L.donovani, L. infantum and L. major, while population coverage analysis predicted 81.61% global coverage. The selected epitopes were assembled into a 209-amino acid vaccine construct using AAY, GPGPG and KK linkers with the TLR4 agonist RS-09 as an adjuvant. The construct was predicted to be antigenic, non-allergenic, stable and soluble whereas structural validation confirmed a high-quality three-dimensional model. Molecular docking demonstrated favourable interaction with the TLR4 receptor, while discontinuous B cell epitope analysis revealed structural similarity between the vaccine construct and the native amastin protein. Normal mode analysis, molecular dynamics simulation and immune simulation further supported the structural stability and immunogenic potential of the vaccine construct. A 100 ns molecular dynamics simulation confirmed the structural stability of the vaccine-TLR4 complex and MM/PBSA and MM/GBSA binding free energy analyses further supported favourable binding affinity between the vaccine construct and TLR4. Codon optimization and in silico cloning indicated favourable expression in the Escherichia coli pET-28a (+) expression system. These computational findings suggest that the proposed multi-epitope vaccine is a promising candidate which requires further experimental validation for realizing its potential as a vaccine against leishmaniasis.