Chlamydia psittaci is an obligate intracellular zoonotic pathogen that causes psittacosis and severe respiratory illness in humans. Despite its clinical importance, no licensed vaccine is currently available, and antibiotic treatment may not provide long-term protection or prevent recurrent infection. To address this challenge, a computational strategy integrating structural vaccinology and immunoinformatics was used to design a multi-epitope vaccine targeting the major outer membrane porin and the virulence-associated pGP3-D protein of C. psittaci. Cytotoxic T-cell and helper T-cell epitopes were identified and screened to select antigenic candidates. The selected epitopes were joined using linker sequences together with β-defensin-3 and PADRE. The vaccine construct was evaluated using physicochemical analysis, three-dimensional structural modeling, interaction analysis with TLR2, a 500 ns molecular dynamics simulation, MM-GBSA binding free-energy analysis, immune simulation, and in silico cloning. The designed vaccine was predicted to possess favorable antigenicity, a non-allergenic profile, suitable physicochemical properties, and a global population coverage of 92.15%. Computational analyses suggested stable interaction with TLR2 and indicated structural stability of the vaccine-receptor complex during the simulation. Immune simulation predicted increased IgG levels, memory B-cell formation, activation of CD8[+] T lymphocytes, and a cytokine profile consistent with Th1-type immune responses. These findings suggest that the proposed construct represents a computationally designed multi-epitope vaccine candidate that requires further evaluation through experimental studies to determine its safety, immunogenicity, and protective efficacy against C. psittaci.

Primary amoebic meningoencephalitis (PAM) is caused by Naegleria fowleri, a free-living amoeba. It is a fatal infection with more than 95% mortality rate. Even though several combinations of antimicrobial agents were used to treat the condition, the overall survival remains poor and no effective vaccine is currently available. In this study, an immunoinformatic approach was utilized for designing a multi-epitope vaccine against N. fowleri. The sequences of antigenic proteins were retrieved for epitope prediction. The computational prediction identified 400 CTL, 590 HTL, and 65 B-cell high-binding epitopes. After evaluating their antigenicity, allergenicity and toxicity, 5 CTL, 5 HTL and 3 B-cell epitopes were selected and assembled into a multi-epitope vaccine construct using linkers and a human β-defensin-3 adjuvant. The 3D structure of the vaccine was predicted using AlphaFold and refined with GalaxyRefine. Ramachandran plot analysis indicated that 96.5% of the residues of the refined vaccine are present in the most favored regions, indicating good stereochemical quality. The molecular docking analysis was performed using HADDOCK to evaluate the interaction between the vaccine and the Toll-like Receptors (TLRs), which predicted favorable binding affinities of -15.6 kcal/mol, -14.2 kcal/mol, and - 13.1 kcal/mol for TLR1 & 2, TLR3, and TLR4, respectively. The codon was optimized using JCat and cloned into the pET-28a(+) plasmid. The in silico immune simulation analysis predicted potential humoral and cellular immune responses to the vaccine construct. Overall, the proposed multi-epitope vaccine represents a promising computational candidate, however, further experimental validations have to be performed to confirm its efficacy against the pathogen.

The Human Leukocyte Antigen (HLA) system is critical for immune recognition and transplantation compatibility. Despite its strategic location at the crossroads of the Caucasus, Anatolia, and the Middle East, comprehensive immunogenetic data for the Azerbaijani population remain limited. This study aimed to characterize HLA-A, -B, and -DRB1 allele-group and haplotype frequencies and establish a framework for optimized donor matching. We analyzed HLA-A, -B, and -DRB1 allele-group frequencies in 2301 healthy donors from Azerbaijan. Data were analyzed using the expectation-maximization algorithm for haplotype estimation, Hardy-Weinberg equilibrium (HWE) testing, and linkage disequilibrium (LD) analysis. An in-house donor matching system was developed to facilitate institutional registry searches. A total of 19 HLA-A, 31 HLAB, and 13 HLA-DRB1 allele groups were identified. The most frequent alleles were A*02 (21.3%), B*35 (17.4%), and DRB1*11 (19.3%). The predominant three-locus haplotype was A02 ∼ B51 ∼ DRB104 (1.02%). Statistical analyses revealed modest deviations from HWE and significant LD between loci. Principal Coordinate Analysis (PCoA) demonstrated that the Azerbaijani population occupies an intermediate immunogenetic position, showing strong affinity with Iranian, South Caucasian, and Anatolian Turkish populations. This study provides the first comprehensive immunogenetic reference for Azerbaijan, deposited in the Allele Frequencies Net Database (AFND: 3853). Our findings highlight a distinct yet regionally connected immunogenetic profile, emphasizing the importance of local donor registries. The integration of these data into an in-house donor matching algorithm offers a vital translational strategy to enhance transplantation success and clinical outcomes in the region.

Genotype-phenotype correlation studies fail to explain the phenotypic diversity in Wilson disease (WD) and the missing link may lie in transcriptomics. Therefore, we performed genome-wide transcriptomic profiling and machine-learning-based random forest modeling (RF) to identify the most important genes that could explain phenotypic variability in WD and reveal the molecular pathogenesis of WD. For this purpose, we used bulk RNA sequencing approaches to include 47 genetically confirmed pediatric hepatic WD patients and controls. We observed 321 differentially expressed genes (DEGs) in WD. Among top 100 DEGs, 42 significant DEGs (p < 0.05) were correlated with Kayser-Fleischer ring, serum ceruloplasmin, 24-h urinary copper levels, PELD score at recruitment, and degree of presentation at diagnosis. The random forest model identified a panel of ten genes: GPR37L1, OIP5, TRAJ23, IGHA2, TDRD1, LILRA4, HMOX2, UGT2B17, IGLV7-46 and EPHA1 that could explain 97.22% of phenotypic variability in WD. Ingenuity pathway analysis ranked MAP kinase pathway highest, driven by upregulation of RPS6KA1 (log2FC = 4.68) and downregulation of DUSP16 (log2FC = -5.22), and GAPLINC (log2FC = -2.45). Iron homeostasis signaling demonstrated comparable enrichment, involving key genes ATP6V0D2 (log2FC = -4.06), HMOX2 (log2FC = -2.70), HBD (log2FC = 1.96) and HBZ (log2FC = 1.76). These results suggest that children with WD have dysregulation in MAP Kinase and iron homeostasis signaling pathways providing an important insight into the molecular pathogenesis of WD. RF modeling identified a panel of biomarker with ten genes, that could explain the phenotypic variability in WD.

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.