Explore the vast range of titles available.

Background/Objectives: Current prophylactic human papillomavirus (HPV) vaccines rely on major capsid proteins (L1). Although highly immunogenic, L1-based immunity is clade-restricted owing to the hypervariability of HPV strains across different geographic regions. This restricts cross-protection against diverse, localized, and non-vaccine viral strains circulating in specific areas, leaving these populations vulnerable to regional genotypes. Methods: We aimed to design a cross-protective vaccine tailored to local viral diversity through evolutionary and immunoinformatic analyses of circulating HPV strains in Thailand. Both major (L1) and minor (L2) capsid proteins were analyzed to evaluate selective evolutionary pressures, structural sequence conservation, and cross-strain promiscuity of predicted B- and T-cell epitopes using the IEDB database. The predicted immunogenic profile of the combined L1/L2 proteins was further assessed using in silico immune response simulations. Results: Evolutionary analysis confirmed that although the L1 protein is under strict purifying selection, it exhibits high regional interclade variability. L1-only epitopes demonstrated restricted cross-strain conservation, creating structural blind spots against divergent regional variants. The minor capsid protein (L2) harbored highly conserved dual-action core peptides that are evolutionarily conserved across multiple HPV type. Incorporation of conserved L2 regions alongside L1 sequences may broaden the predicted epitope coverage and help address limitations associated with L1 variability. The proposed multi-targeted L1/L2 construct therefore represents a computational framework for the development of candidate cross-reactive HPV vaccines relevant to circulating Thai genotypes. However, experimental validation remains necessary to determine immunogenicity, cross-neutralization potential, and protective efficacy. Conclusion: Our findings highlight these conserved HPV epitopes as potential targets for future development of next-generation cross-subtype prophylactic vaccines with broader population coverage.

Q fever is one of the most important zoonotic diseases caused by the obligate intracellular bacteria, Coxiella burnetii . This bacterial infection has been frequently reported in both humans and animals, especially ruminants. Ticks are important ectoparasite and serve as reservoir hosts of Coxiella -like endosymbionts (CLEs). In this study, we have attempted to express chaperone-coding genes from CLEs of Rhipicephalus annulatus ticks collected fromcow path. The partial DnaK coding sequence has been amplified and expressed by Escherichia coli . Amino acid sequences have been analyzed by MS-MS spectrometry and the UniProt database. Despites nucleotide sequences indicating high nucleotide variation and diversity, many nucleotide substitutions are synonymous. In addition, amino acid substitutions compensate for the physicochemical properties of the original amino acids. Immune Epitope Database and Analysis Resource (IEDB-AR) was employed to indicate the antigenicity of the partial DnaK protein and predict the epitopes of B-and T-cells. Interestingly, some predicted HLA-A and B alleles of the MHC-I and HLA-DR alleles belonging to MHC-II were similar to T-cell responses to C . burnetii in Q fever patients. Therefore, the partial DnaK protein of CLE from R . annulatus could be considered a vaccine candidate and immunogenic marker with future prospects.

Background Canine circovirus (CanineCV) is a single-stranded circular DNA virus that infects domestic and wild canids in many countries. CanineCV is associated with gastroenteritis and diarrhea, respiratory disease, and generalized vasculitis leading to a fatal event. The Capsid protein (Cap) is a structural protein of the virus which has high genetic variability and plays a role in the canine immune response. In this study, we cloned the full-length CanineCV Capsid gene ( Cap ). In-silico analyses were used to explore the genomic and amino acid variability and natural selection acting on the Cap gene. The immune relevance for T-cell and B-cell epitopes was predicted by the immunoinformatic approach. Results According to the Cap gene, our results showed that CanineCV was separated into five phylogenetic groups. The obtained CanineCV strain from this study was grouped with the previously discovered Thai strain (MG737385), as supported by a haplotype network. Entropy analyses revealed high nucleotide and amino acid variability of the Capsid region. Selection pressure analysis revealed four codons at positions 24, 50, 103, and 111 in the Cap protein evolved under diversifying selection. Prediction of B-cell epitopes exhibited four consensus sequences based on physiochemical properties, and eleven peptide sequences were predicted as T-cell epitopes. In addition, the positive selection sites were located within T-cell and B-cell epitopes, suggesting the role of the host immune system as a driving force in virus evolution. Conclusions Our study provides knowledge of CanineCV genetic diversity, virus evolution, and potential epitopes for host cell immune response.

Babesia bovis and B. bigemina are the most common tick-borne parasites that cause bovine babesiosis which effects livestock production, leading to economic losses in tropical and subtropical areas of the world. The aims of this study were to determine the molecular detection, genetic diversity and antigenicity prediction of B. bovis based on spherical body protein 2 ( sbp-2 ) gene and B. bigemina based on rhoptry-associated protein 1a ( rap-1a ) gene in cattle in Thailand. By PCR assay, the molecular detection of B. bovis and B. bigemina infection revealed levels of 2.58% (4/155) and 5.80% (9/155), respectively. The phylograms showed that B. bovis sbp-2 and B. bigemina rap-1a sequences displayed 5 and 3 clades with similarity ranging between 85.53 to 100% and 98.28 to 100%, respectively, when compared within Thailand strain. Diversity analysis of sbp-2 and rap-1a sequences showed 18 and 4 haplotypes, respectively. The entropy analysis illustrated 104 and 7 polymorphic sites of sbp-2 and rap-1a nucleic acid sequences, respectively, while those of sbp-2 and rap-1a amino acid sequences showed 46 and 4 high entropy peaks, respectively. Motifs analysis exhibited the distribution and conservation among sbp-2 and rap-1a sequences. The continuous and discontinuous B-cell epitopes have also been evaluated in this work. Therefore, our findings may be used to ameliorate the understanding inputs of molecular phylogeny, genetic diversity and antigenicity of B. bovis and B. bigemina Thailand stains.

Canine circovirus (CanineCV) is a contagious virus that causes severe gastroenteritis, diarrhea, respiratory disease, and vasculitis, often resulting in fatality among infected dogs. In this study, a recombinant Capsid protein (rCap) of CanineCV was expressed in the Escherichia coli ( E. coli ) Rosetta (DE3) pLysS host cell, followed by affinity purification, and then analyzed by SDS-PAGE, revealing a molecular weight of approximately 31 kDa. The antigenicity of the CanineCV rCap protein was confirmed through recognition by a rabbit anti-CanineCV rCap protein polyclonal antibody (PoAb). Additionally, the reactivity and specificity of this PoAb were assessed using indirect enzyme-linked immunosorbent assay (ELISA) and Western blot analysis before applying in an immunohistochemistry (IHC), namely, immunoperoxidase detection. The immunoperoxidase assay using rabbit anti-CanineCV rCap protein PoAb demonstrated that the CanineCV Cap protein was predominantly located in immune cells, especially lymphocytes and macrophages, within the spleen, lung, tracheobronchial lymph nodes, small intestine, and kidney. Similarly, the Cap protein was also found in pneumocytes in the lung and renal tubular epithelial cells in the kidney. These findings reflected the biological activity and cell tropism of the virus. Therefore, the recombinant Cap protein and its PoAb could be used for the development of a valuable diagnostic tool for CanineCV detection.

Leucocytozoon sabrazesi is an intracellular haemoprotozoan parasite responsible for leucocytozoonosis, which is transmitted by insect vectors and affects chickens in tropical and subtropical areas in many countries. It causes huge economic losses due to decreased meat and egg production. In the present study, we used nested PCR to determine the genetic diversity of L. sabrazesi based on the cytb, coxI, coxIII and concatenated genes in chickens in Thailand. In addition, we found co-infections between L. sabrazesi and Plasmodium spp. ( P. gallinaceum or P. juxtanucleare ) in chickens that were not identified by microscopic examination of blood smears. The phylogenetic analysis indicated that L. sabrazesi cytb and coxIII genes were conserved with similarity ranging from 99.9 to 100% and 98 to 100%, respectively whereas the coxI gene was diverse, with similarities ranging from 97 to 100%. These findings ascertained the nucleotide analysis of the cytb, coxI, coxIII and concatenated sequences in which 4, 8, 10 and 9 haplotypes were found, respectively. In addition, it was found that the large number of synonymous substitutions and conservative amino acid replacements in these mitochondrial genes occurred by non-synonymous substitution. The evolutionary analysis of the K a / K s ratio supported purifying selection and the negative values of both Fu’s F s and Tajima’s D indicate selective sweep especially for the coxI gene. The entropy and Simplot analysis showed that the genetic variation in populations of Plasmodium spp. was higher than in Leucocytozoon. Hence, the nucleotide sequences of three mitochondrial genes could reflect the evolutionary analysis and geographic distribution of this protozoan population that switches hosts during its life cycle. Leucocytozoon sabrazesi est le parasite hémoprotozoaire intracellulaire responsable de la leucocytozoonose, qui est transmise par des insectes vecteurs et affecte les poulets dans les zones tropicales et subtropicales de nombreux pays. Il provoque d’énormes pertes économiques en raison de la diminution de la production de viande et d’œufs. Dans la présente étude, nous avons utilisé la PCR nichée pour déterminer la diversité génétique de L. sabrazesi sur la base des gènes cytb, coxI, coxIII et concaténés chez des poulets en Thaïlande. De plus, nous avons trouvé des co-infections entre L. sabrazesi et Plasmodium spp. ( P. gallinaceum ou P. juxtanucleare ) chez des poulets, qui n’ont pas été identifiées par l’examen microscopique de frottis sanguins. L’analyse phylogénétique a indiqué que les gènes cytb et coxIII de L. sabrazesi étaient conservés avec une similarité allant respectivement de 99,9 à 100 % et de 98 à 100 %, alors que le gène coxI était diversifié, avec des similarités allant de 97 à 100 %. Ces découvertes ont confirmé l’analyse des nucléotides des séquences cytb, coxI, coxIII et concaténées dans lesquelles 4, 8, 10 et 9 haplotypes ont été trouvés, respectivement. De plus, il a été constaté que le grand nombre de substitutions synonymes et de remplacements conservateurs d’acides aminés dans ces gènes mitochondriaux se produisaient par substitution non synonyme. L’analyse évolutive du rapport K a / K s a soutenu la sélection purificatrice et les valeurs négatives des Fs de Fu et D de Tajima indiquent un balayage sélectif, en particulier pour le gène coxI. L’entropie et l’analyse Simplot ont montré que la variation génétique de la population de Plasmodium spp. était plus élevée que pour Leucocytozoon . Par conséquent, les séquences nucléotidiques de trois gènes mitochondriaux pourraient refléter l’analyse évolutive et la répartition géographique de cette population de protozoaires qui changent d’hôte au cours de leur cycle de vie.