Potential B-cell Research Articles

Molecular characterization and B-cell epitope analysis of the TSP11 gene in Echinococcus infection strains from Yunnan Province.

This study investigates the molecular intricacies of the transmembrane protein TSP11 gene in Echinococcus strains isolated from livestock and patients in Yunnan Province afflicted with Echinococcus granulosus (E. granulosus) between 2016 and 2020. Gene typing analysis of the ND1 gene revealed the presence of the G1 type, G5 type and untyped strains, constituting 52.4, 38.1 and 9.5%, respectively. The analysis of 42 DNA sequences has revealed 24 novel single nucleotide polymorphic sites, delineating 11 haplotypes, all of which were of the mutant type. Importantly, there were no variations observed in mutation sites or haplotypes in any of the hosts. The total length of the TSP11 gene's 4 exons is 762 bp, encoding 254 amino acids. Our analysis posits the existence of 6 potential B-cell antigenic epitopes within TSP11, specifically at positions 49-KSN-51, 139-GKRG-142, 162-DNG-164, 169-NGS-171, 185-DS-186 and 231-PPRFTN-236. Notably, these epitopes exhibit consistent presence among various intermediate hosts and haplotypes. However, further validation is imperative to ascertain their viability as diagnostic antigens for E. granulosus in the Yunnan Province.

Developing a chimeric multiepitope vaccine against Nipah virus (NiV) through immunoinformatics, molecular docking and dynamic simulation approaches

Nipah virus (NiV) is a highly lethal zoonotic pathogen that poses a significant threat to human and animal health. Unfortunately, no effective treatments have been developed for this deadly zoonotic disease. Therefore, we designed a chimeric multiepitope vaccine targeting the Nipah virus (NiV) glycoprotein and fusion protein through immunoinformatic approaches. Therefore, the vaccine was developed by combining promising and potential antigenic MHC-I, MHC-II, and B-cell epitopes obtained from the selected proteins. When combined, the MHC-I and MHC-II epitopes offered 100 % global population coverage. The physicochemical characterization also exhibited favorable properties, including solubility and potential functional stability of the vaccine within the body (GRAVY score of −0.308). Structural analyses unveiled a well-stabilized secondary and tertiary structure with a Ramachandran score of 84.4 % and a Z score of −5.02. Findings from docking experiments with TLR-2 (−1089.3 kJ/mol) and TLR-4 (−1016.7 kJ/mol) showed a strong affinity of the vaccine towards the receptor. Molecular dynamics simulations revealed unique conformational dynamics among the “vaccine-apo,” “vaccine-TLR-2,” and “vaccine-TLR-4″ complexes. Consequently, the complexes exhibited significant compactness, flexibility, and exposure to solvents. The results of the codon optimization were remarkable, as the vaccine showed a significant amount of expression in the E. coli vector (GC content of 45.36 % and a CAI score of 1.0). The results of immune simulations, however, showed evidence of both adaptive and innate immune responses induced by the vaccine. Therefore, we highly recommend further research on this chimeric multiepitope vaccine to establish its efficacy and safety against the Nipah virus (NiV).

Comprehensive bioinformatics assessments of the ROP34 of Toxoplasma gondii to approach vaccine candidates

IntroductionRhoptries proteins (ROPs) are crucial throughout different stages of the Toxoplasma gondii (T. gondii) lifecycle, playing key roles in both the invasion of host cells and their subsequent survival. ROP34 is particularly noteworthy as it significantly influences host gene expression and aids in the transition from the tachyzoite to the bradyzoite form.Materials and methodsThis research utilized various bioinformatics tools to assess physico-chemical properties, allergenic and antigenic characteristics, sites for post-translational modifications (PTMs) and protein's secondary and three-dimensional structures of the ROP34 protein. Furthermore, the study identified potential B-cell, MHC-binding, and cytotoxic T-lymphocyte (CTL) epitopes within the ROP34 sequence.ResultsThe ROP34 peptide comprised 553 amino acid residues, with a calculated average molecular weight (MW) of 61.60149 kDa, an aliphatic index of 73.98, and a GRAVY score of − 0.554. The antigenicity of the multi-epitope peptide was estimated to be 0.526563 and 0.6025 by the ANTIGENpro and VaxiJen servers, respectively, suggesting ROP34 as an immunogenic protein with no allergenic potential. Secondary structure analysis revealed a composition of 52.80% random coil, 36.17% alpha helix, and 11.03% extended strand. The Ramachandran plot for the refined model depicted that 97.46% of the residues were situated in the favored region.ConclusionThis in silico research serves as a foundation for designing effective immunization tactics to target toxoplasmosis. The present article lays the groundwork for future studies and offers perspectives for the advancement of an appropriate toxoplasmosis vaccine.Graphical

In silico Identification of MHC Displayed Tumor Associated Peptides in Ovarian Cancer for Multi-Epitope Vaccine Construct.

Recognizing the potential of the immune system, immunotherapies have brought about a revolution in the treatment of cancer. Low tumour mutational burden and strong immunosuppression in the peritoneal tumor microenvironment (TME) lead to poor outcomes of immune checkpoint inhibition (ICI) and CART cell therapy in ovarian cancer. Alternative immunotherapeutic strategies are of utmost importance to achieve sound clinical success. The development of peptide vaccines based on tumor-associated antigens (TAAs) for ovarian cancer cells can be a potential target to provoke an anti-tumor immune response and subsequent clearance of tumour cells. The purpose of this in silico study was to find potential epitopes for a multi-epitope vaccine construct using the immunopeptidomics landscape of ovarian carcinoma. The four TAAs (MUC16, IDO1, FOLR1, and DDX5) were selected for potential epitopes prediction. The epitopes for B-cells, helper T-lymphocytes (HTL), and Cytotoxic Tlymphocytes (CTL) were predicted on the basis of antigenic, allergenic, and toxic properties. These epitopes were combined with suitable linkers and an adjuvant to form a multi-epitope construct. Four HTLs, 13 CTLs, and 6 potential B-cell epitopes were selected from the predicted epitope. The designed multi-epitope construct was potentially immunogenic, non-toxic, and non-allergenic. Physicochemical properties and higher-order structural analyses of the final construct revealed a potential vaccine candidate. The designed vaccine construct has the potential to trigger both humoral and cellular immune responses and may be employed as a therapeutic immunization candidate for ovarian malignancies. However, further in vitro and animal experimentation is required to establish the efficacy of the vaccine candidate.

Whole-genome sequence analysis of canine parvovirus reveals replacement with a novel CPV-2c strain throughout India.

Canine parvovirus (CPV) infection causes severe gastroenteritis in canines, with high mortality in puppies. This virus evolved from feline panleukopenia virus by altering its transferrin receptor (TfR), followed by the emergence of CPV-2 variants in subsequent years with altered immunodominant amino acid residues in the VP2 protein. While previous studies have focused on the VP2 gene, there have been fewer studies on non-structural protein (NS1 and NS2) genes. In the present study, CPV genome sequences from clinical samples collected from canines throughout India in 2023, previous Indian CPV isolates from 2009-2019, and the current Indian CPV vaccine strain were compared. The study showed that the CPV-2c (N426E) variant had almost completely replaced the previously dominant CPV-2a variant (N426) in India. The Q370R mutation of VP2 was the most common change in the recent CPV-2c strain (CPV-2c 370Arg variant). Phylogenetic analysis showed the existence of three clades among the recent CPV-2c strains, and sequence analysis identified several new sites of positive selection in the VP1 (N-terminus), VP2, NS1, and NS2 protein-encoding genes in recent CPV strains, indicating the emergence of new CPV-2c variants with varied antigenic and replication properties. The predominant 'CPV-2c 370Arg variants' were grouped with the Chinese and Nigerian CPV-2c strains but were separate from the CPV vaccine strain and earlier isolates from our repository. VP2 epitope analysis predicted nine amino acid variations (including two new variations) in four potential linear B-cell epitopes in the CPV-2c 370Arg variants that might make vaccine failure more likely. This pan-Indian study lays the foundation for further research concerning the dynamics of virus evolution and understanding genetic mutations.

Characterization of capsid protein of porcine circovirus 4 by in-silico approach

Porcine Circovirus 4 (PCV4) has been detected in pigs from China only in 2019. PCV4 has been found to be associated with several forms of clinical syndromes in pigs. Like other Porcine Circoviruses, the only structural protein of PCV4 is the capsid protein. Therefore, it could be a key vaccine candidate or diagnostic marker. The present study aims to characterize the capsid protein of PCV4 by using several bioinformatics tools. The in-silico analysis revealed that the molecular weight of PCV4 capsid protein is about 27.3 kDa which is made up of 228 amino acids. The capsid protein of PCV4 contains a nuclear localization signal at N-terminal and several post-translational modifications could be predicted at different residues of the protein. The secondary structure of capsid protein contains coil, beta strand, and alpha helix. The 3D structure of the protein was predicted with a high level of confidence. The capsid protein of PCV4 also contains several potential B-cell epitopes. Thus, the in-silico characterization of the capsid protein will be beneficial in designing diagnostics and vaccine candidates in future to combat PCV4 infection in pigs.

Comprehensive Analysis of Conserved B-Cell Epitopes in DENV NS1 Protein for Enhanced Rapid Diagnostic Tests Development in Indonesia

Dengue virus (DENV) constitutes a formidable public health threat within tropical and subtropical regions. The escalation of cases in Southeast Asia, notably Indonesia, is a matter of considerable concern. Timely identification of DENV infection remains imperative for efficient disease management. The non-structural protein-1 (NS1), distinguished by its heightened immunogenicity and early detectability during infection, stands as a pivotal target for diagnostic modalities. The current investigation delves into the exploration of B-cell epitopes within Indonesian DENV NS1 protein isolates, with the overarching objective of enhancing the sensitivity and specificity of early detection systems, such as the Rapid Diagnostic Test (RDT). This study has successfully delineated five B-cell epitopes that exhibit conservation across DENV serotypes within Indonesian isolates (accessions number: QBB90021.1, QBE90252.1, QBB90023.1, and UDW38833.1). These epitopes were discerned through comprehensive screening leveraging the IEDB platforms. Noteworthy variations in antigenicity, allergenicity, and toxicity profiles were observed among these identified epitopes. Molecular docking analysis substantiated a robust binding affinity between the predicted epitope and the B-cell receptor. The ensuing in silico protein-peptide docking analyses offer valuable insights into potential B-cell epitopes on the Indonesian DENV NS1 protein. The identified epitopes, particularly the SQHNYRPGY epitope characterized by its antigenic potency and non-allergenic attributes, hold promise for advancing the development of sensitive and specific RDTs tailored for DENV detection in the Indonesian context. However, it is imperative to underscore the requisite for subsequent experimental validation to affirm the efficacy of these epitopes in diagnostic applications.

Design of multi-epitope vaccine against porcine rotavirus using computational biology and molecular dynamics simulation approaches

Porcine Rotavirus (PoRV) is a significant pathogen affecting swine-rearing regions globally, presenting a substantial threat to the economic development of the livestock sector. At present, no specific pharmaceuticals are available for this disease, and treatment options remain exceedingly limited. This study seeks to design a multi-epitope peptide vaccine for PoRV employing bioinformatics approaches to robustly activate T-cell and B-cell immune responses. Two antigenic proteins, VP7 and VP8*, were selected from PoRV, and potential immunogenic T-cell and B-cell epitopes were predicted using immunoinformatic tools. These epitopes were further screened according to non-toxicity, antigenicity, non-allergenicity, and immunogenicity criteria. The selected epitopes were linked with linkers to form a novel multi-epitope vaccine construct, with the PADRE sequence (AKFVAAWTLKAAA) and RS09 peptide attached at the N-terminus of the designed peptide chain to enhance the vaccine’s antigenicity. Protein-protein docking of the vaccine constructs with toll-like receptors (TLR3 and TLR4) was conducted using computational methods, with the lowest energy docking results selected as the optimal predictive model. Subsequently, molecular dynamics (MD) simulation methods were employed to assess the stability of the protein vaccine constructs and TLR3 and TLR4 receptors. The results indicated that the vaccine-TLR3 and vaccine-TLR4 docking models remained stable throughout the simulation period. Additionally, the C-IMMSIM tool was utilized to determine the immunogenic triggering capability of the vaccine protein, demonstrating that the constructed vaccine protein could induce both cell-mediated and humoral immune responses, thereby playing a role in eliciting host immune responses. In conclusion, this study successfully constructed a multi-epitope vaccine against PoRV and validated the stability and efficacy of the vaccine through computational analysis. However, as the study is purely computational, experimental evaluation is required to validate the safety and immunogenicity of the newly constructed vaccine protein.

Immunoinformatics and structural aided approach to develop multi-epitope based subunit vaccine against Mycobacterium tuberculosis

Tuberculosis is a highly contagious disease caused by Mycobacterium tuberculosis (Mtb), which is one of the prominent reasons for the death of millions worldwide. The bacterium has a substantially higher mortality rate than other bacterial diseases, and the rapid rise of drug-resistant strains only makes the situation more concerning. Currently, the only licensed vaccine BCG (Bacillus Calmette–Guérin) is ineffective in preventing adult pulmonary tuberculosis prophylaxis and latent tuberculosis re-activation. Therefore, there is a pressing need to find novel and safe vaccines that provide robust immune defense and have various applications. Vaccines that combine epitopes from multiple candidate proteins have been shown to boost immunity against Mtb infection. This study applies an immunoinformatic strategy to generate an adequate multi-epitope immunization against Mtb employing five antigenic proteins. Potential B-cell, cytotoxic T lymphocyte, and helper T lymphocyte epitopes were speculated from the intended proteins and coupled with 50 s ribosomal L7/L12 adjuvant, and the vaccine was constructed. The vaccine’s physicochemical profile demonstrates antigenic, soluble, and non-allergic. In the meantime, docking, molecular dynamics simulations, and essential dynamics analysis revealed that the multi-epitope vaccine structure interacted strongly with Toll-like receptors (TLR2 and TLR3). MM-PBSA analysis was performed to ascertain the system’s intermolecular binding free energies accurately. The immune simulation was applied to the vaccine to forecast its immunogenic profile. Finally, in silico cloning was used to validate the vaccine’s efficacy. The immunoinformatics analysis suggests the multi-epitope vaccine could induce specific immune responses, making it a potential candidate against Mtb. However, validation through the in-vivo study of the developed vaccine is essential to assess its efficacy and immunogenicity profile, which will assure active protection against Mtb.

Development of recombinant proteins for vaccine candidates against serotypes O and A of Foot-and-Mouth Disease virus in Bangladesh.

Frequent vaccine failure leading to recurrent outbreaks of Foot-and-Mouth Disease (FMD) in livestock populations necessitates the development of a customizable vaccine platform comprising potential antigenic determinants of circulating lineages of FMD viruses. Artificially designed, chimaeric protein-based recombinant vaccines are novel approaches to combat the phylogenetically diverse FMD Virus (FMDV) strains. Among seven recognized serotypes, only serotypes O and A are dominantly circulating in Bangladesh and neighbouring countries of Asia, where transboundary transmission, recurrent outbreaks and emergence of novel lineages of FMDV are highly prevalent. The objective of this study was to develop multi-epitope recombinant proteins, procuring immunogenicity against circulating diverse genotypes of FMDV serotypes O and A. Two chimaeric proteins, named B1 (41.0 kDa) and B3 (39.3 kDa), have been designed to incorporate potential B-cell and T-cell epitopes selected from multiple FMDV strains, including previously reported and newly emerged sub-lineages. After expression, characterization and immunization of guinea pigs with a considerable antigen load of B1 and B3 followed by serological assays revealed the significant protective immunogenicity, developed from the higher (100 µg) doses of both antigens, against most of the currently prevalent serotype O and A strains of FMDV. The efficient expression, antigenic stability, and multivalent immunogenic potency of the chimaeric proteins strongly indicate their credibility as novel vaccine candidates for existing serotypes O and A of FMDV in Bangladesh and surrounding territories.

Muscle Transcriptome Provides Insights into the Allergen Profile of Habitat-specific Mature Hilsa shad (Tenualosa ilisha)

Background: Hilsa shad (Tenualosa ilisha) is a popular anadromous fish in Bangladesh known to cause allergies. Despite recognized allergenicity, there is a paucity of research at the molecular level on hilsa allergen. Methods: Muscle transcriptomes of hilsa from freshwater, brackish, and deep sea habitats were sequenced using Illumina NovaSeq 6000 and assembled. BLASTx analysis of the Allergen Online database identified potential allergens. The molecular docking study investigated parvalbumin’s interaction with human IgE. Results: An analysis of hilsa muscle transcriptomes revealed 28 known fish allergens, including parvalbumin, tropomyosin, including parvalbumin, tropomyosin, filamin C, creatine kinase-2, aldolase A, triosephosphate isomerase B, and Glyceraldehyde-3-phosphate Dehydrogenase (G3PD). Creatine kinase showed significantly higher abundance (p < 0.05) and habitat variation (freshwater vs. brackish water). In silico analysis suggested upregulation of Sal s 2 enolase and Equ c 6 lysozyme in freshwater and brackish water compared to the deep sea. Docking studies identified a potential B-cell epitope in parvalbumin that interacts with human IgE. Conclusion: This study has unveiled 28 potential allergens in hilsa, including habitat-specific variations. The parvalbumin-IgE interaction has been suggested as a mechanism for allergies. The findings have illuminated fish allergy in Bangladesh and paved the way for further investigation.

Systems approach to design multi-epitopic peptide vaccine candidate against fowl adenovirus structural proteins for Gallus gallus domesticus.

Fowl adenovirus (FAdV) is a significant pathogen in poultry, causing various diseases such as hepatitis-hydropericardium, inclusion body hepatitis, and gizzard erosion. Different serotypes of FAdV are associated with specific conditions, highlighting the need for targeted prevention strategies. Given the rising prevalence of FAdV-related diseases globally, effective vaccination and biosecurity measures are crucial. In this study, we explore the potential of structural proteins to design a multi-epitope vaccine targeting FAdV. We employed an in silico approach to design the multi-epitope vaccine. Essential viral structural proteins, including hexon, penton, and fiber protein, were selected as vaccine targets. T-cell and B-cell epitopes binding to MHC-I and MHC-II molecules were predicted using computational methods. Molecular docking studies were conducted to validate the interaction of the multi-epitope vaccine candidate with chicken Toll-like receptors 2 and 5. Our in silico methodology successfully identified potential T-cell and B-cell epitopes within the selected viral structural proteins. Molecular docking studies revealed strong interactions between the multi-epitope vaccine candidate and chicken Toll-like receptors 2 and 5, indicating the structural integrity and immunogenic potential of the designed vaccine. The designed multi-epitope vaccine presents a promising approach for combating FAdV infections in chickens. By targeting essential viral structural proteins, the vaccine is expected to induce a robust immunological response. The in silico methodology utilized in this study provides a rapid and cost-effective means of vaccine design, offering insights into potential vaccine candidates before experimental validation. Future studies should focus on in vitro and in vivo evaluations to further assess the efficacy and safety of the proposed vaccine.

Precision Vaccine Development: Unraveling the Immunoinformatics Code Against Epstein-Barr Virus's T41 Glycoprotein 350/220

Epstein-Barr Virus (EBV) poses a substantial global health threat, with a 90% morbidity rate in adults worldwide. Linked to infectious mononucleosis, autoimmune diseases, and cancers, there is an imperative for effective preventive measures, given the absence of current vaccines or medications. This study employs a bioinformatics strategy to design an epitope vaccine targeting EBV. The primary target for immunity is the EBV glycoprotein 350/220 (gp350), which mediates attachment to B cells through complement receptor 2 (CR2/CD21). The selected protein, EBV glycoprotein 350/220 was chosen based on its role in pathogenicity. In the post-therapeutic approach, three-dimensional structure prediction, validation, and verification processes were conducted, followed by molecular docking studies to identify potential drug-binding sites and suitable therapeutic inhibitors for the target protein. The protein's ability to stimulate humoral and cell-mediated immunity was assessed, leading to the identification of a peptide segment ATNLFLLEL from positions 342 to 356 as the predominant T cell epitope. This epitope demonstrated compatibility with various HLA profiles, enhanced by its interaction with eight HLA-A and HLA-B alleles. Population coverage analysis revealed broad responsiveness across geographies, suggesting its potential as a widely applicable vaccine component. Its non-allergic classification further supports its potential efficacy for diverse individuals. Docking studies with HLA-B*3501 confirmed its significant affinity for MHC-I molecules, establishing it as a promising vaccination candidate. Additionally, a region from amino acid positions 253 to 310 was identified as containing potential B-cell epitopes, with the sequence "LGAGELALTMRSKKLP" showing promise due to its antigenic potential. This computational approach to epitope-based peptide vaccine design and target site prediction against EBV represents a pioneering advancement in EBV virus research, emphasizing the need for validation through <i>in vitro</i> and <i>in vivo</i> trials.

Differential effects of heating modes on the immunogenic potential of soy-derived peptides released after in vitro infant digestion

During production of soy-based infant formula, soy protein undergoes heating processes. This study investigated the differential impact of heating modes on the immunogenic potential of peptides in soy protein digests. Wet or dry heating was applied, followed by in vitro gastrointestinal infant digestion. The released peptides were analyzed by LC-MS/MS. Bioinformatics tools were utilized to predict and identify potential linear B-cell and T-cell epitopes, as well as to explore cross-reactivity with other legumes. Subsequently, the peptide intensities of the same potential epitope across different experimental conditions were compared. As a result, we confirmed the previously observed enhancing effect of wet heating on infant digestion and inhibitory effect of dry heating. A total of 8,546 peptides were detected in the digests, and 6,684 peptides were with a score over 80. Among them, 29 potential T-cell epitopes and 27 potential B-cell epitopes were predicted. Cross-reactivity between soy and other legumes, including peanut, pea, chickpea, lentil, kidney bean, and lupine, was also detected. Overall, heating and digestion time could modulate the potential to trigger peptide-induced immune responses.

Designing of a novel and potent HPV66 L1 major capsid protein-epitope based therapeutic vaccine against Human Papillomavirus (HPV): A bioinformatics approach

Aim: Oncogenic human papillomaviruses (HPV) cause various types of cancer, including cervical cancer. The main protein of HPV is capsid, targeted in many vaccine attempts. However, these vaccines do not cover enough high-risk HPV serotypes. Therefore, a low-cost potential HPV vaccine to protect against all serovars of the α-papillomaviruses family would be promising in the future. Our study aimed to develop a therapeutic epitope vaccine for HPV using bioinformatics methods. Methodology: Bioinformatics approach was followed to analyze and identify potential T-cell and B-cell dominant epitopes of HPV-66 L1 major capsid protein. Additionally, various aspects of this protein were examined, including its physico-chemical properties, and secondary and tertiary structures. These analyses helped us to design an effective HPV infection therapeutic vaccine. Results: The findings revealed that the L1 major capsid protein was unstable and hydrophilic. The secondary structure of this protein composed 39% α- helices, 17.97% β sheets and 31.80% loops. Our study demonstrated 19 dominant epitopes of HPV-66 L1 major capsid protein including 5 B-cell epitopes and 14 T-cell epitopes (10 HTL epitopes, and 4 CTL epitopes) for a novel vaccine candidate. Interpretation: This study provides a comprehensive biological information about the HPV-66 L1 major capsid protein, which will serve as a theoretical foundation for developing a multi-epitope vaccine against HPV infection. Key words: B-cell epitope, Cervical Cancer, Human papillomavirus, HPV66 L1 major capsid protein, T-cell epitope

B-Cell Activation Biomarkers in Salivary Glands Are Related to Lymphomagenesis in Primary Sjögren's Disease: A Pilot Monocentric Exploratory Study.

Primary Sjögren's disease is primarily driven by B-cell activation and is associated with a high risk of developing non-Hodgkin's lymphoma (NHL). Over the last few decades, microRNA-155 (miR-155) has arisen as a key regulator of B-cells. Nevertheless, its role in primary Sjögren's disease remains elusive. Thus, the purpose of this study was (i) to explore miR-155, B-cell activating factor (BAFF)-receptor (BAFF-R), and Interleukin 6 receptor (IL-6R) expression in the labial salivary glands (LSG) of patients with primary Sjögren's disease, aiming to identify potential B-cell activation biomarkers related to NHL development. Twenty-four patients with primary Sjögren's disease, and with available tissue blocks from a LSG biopsy performed at diagnosis, were enrolled. Among them, five patients developed B-cell NHL during follow-up (7.3 ± 3.1 years). A comparison group of 20 individuals with sicca disease was included. Clinical and laboratory parameters were recorded and the LSG biopsies were evaluated to assess local inflammation in terms of miR-155/BAFF-R and IL-6R expression. Stratifying the primary Sjögren's disease cohort according to lymphomagenesis, miR-155 was upregulated in primary Sjögren's disease patients who experienced NHL, more so than those who did not experience NHL. Moreover, miR-155 expression correlated with the focus score (FS), as well as BAFF-R and IL-6R expression, which were increased in primary Sjögren's disease patients and in turn related to neoplastic evolution. In conclusion, epigenetic modulation may play a crucial role in the aberrant activation of B-cells in primary Sjögren's disease, profoundly impacting the risk of NHL development.

Evaluating the Genetic Diversity of the Plasmodium vivax siap2 Locus: A Promising Candidate for an Effective Malaria Vaccine?

Malaria is the deadliest parasitic disease in the world. Traditional control measures have become less effective; hence, there is a need to explore alternative strategies, such as antimalarial vaccines. However, designing an anti-Plasmodium vivax vaccine is considered a challenge due to the complex parasite biology and the antigens´ high genetic diversity. Recently, the sporozoite invasion-associated protein 2 (SIAP2) has been suggested as a potential antigen to be considered in vaccine design due to its significance during hepatocyte invasion. However, its use may be limited by the incomplete understanding of gene/protein diversity. Here, the genetic diversity of pvsiap2 using P. vivax DNA samples from Colombia was assessed. Through PCR amplification and sequencing, we compared the Colombian sequences with available worldwide sequences, revealing that pvsiap2 displays low genetic diversity. Molecular evolutionary analyses showed that pvsiap2 appears to be influenced by directional selection. Moreover, the haplotypes found differ by a few mutational steps and several of them were shared between different geographical areas. On the other hand, several conserved regions within PvSIAP2 were predicted as potential B-cell or T-cell epitopes. Considering these characteristics and its role in hepatocyte invasion, the PvSIAP2 protein emerges as a promising antigen to be considered in a multi-antigen-multi-stage (multivalent) fully effective vaccine against P. vivax malaria.

Search for New Potential T-Cell and B-Cell Epitopes in the Spike Protein of SARS-CoV-2

Search for New Potential T-Cell and B-Cell Epitopes in the Spike Protein of SARS-CoV-2

Human Single Domain Antibody-Based CAR-T Cells Targeting BAFF-R Demonstrate Promising Preclinical Activity in B Cell Malignancies

Background: B-cell activating factor-receptor (BAFF-R) is a potential B-cell specific target, highly expressed in B cell malignancies and regulates B cell proliferation and survival. Single-chain antibody-based CAR-T cells targeting BAFF-R (PMB101) has demonstrated antitumor effects against human B cell malignancies and can overcome CD19 antigen loss (Qin et al. Sci Transl Med. 2019;11(511)). However, CARs built on antigen-specific single chain antibody variable fragment (scFv) may have some immunological risks. Recently, single variable domain of heavy chain antibodies are becoming an alternative to scFv to construct CARs. To improve the function of BAFF-R CAR-T cells, we designed CARs with only a fully human heavy-chain variable domain. Methods: A fully human antibody phage display library (IMARS, IASO Biotherapeutics) was used to select anti-BAFF-R clones using optimal protein/cell alternate panning. The enzyme-linked immunosorbent assay (ELISA) and flow cytometry were applied to evaluate the specificity of clones. The screened clones were grafted into a second-generation CAR with CD8α hinge, 4-1BB costimulatory and CD3ζ intracellular signaling domains to generate CAR-T cells. PMB101 and CAR-T cells constructed with VAY736 were used as positive controls. Non-transduced T cells from the same donor were used as a negative control. Results: Four candidate clones including clone 1, 5, 77 and 80 were finally screened by in vitro functional evaluation, among which clone 5, 77 and 80 were variable domain heavy chain antibodies. The expression levels of the degranulation marker CD107a on CAR-T cells constructed with the four candidate clones were significantly upregulated after coculture with BAFF-R positive tumor cells, while BAFF-R negative tumor cells could not effectively activate CAR-T cells (data not shown). The four clones exhibited similar cytotoxicity in CAR-T cells compared with the PMB101 and VAY736 CAR-T cells using the luciferase-based cytotoxicity assay (data not shown). Xenografts were established in NPG mice following intravenous injection of 1 x 10 6 jeko-1 cells expressing the firefly luciferase gene on day - 5, and a single dose of 4 x 10 6 CAR T cells were infused IV on day 0. Compared to the other groups, no progressive tumor growth was discovered in mice treated with clone 5 CAR-T cells until day 49. Clone 5 CAR-T cells showed excellent in vivo antitumor activity to PMB101 and conferred long-term survival (data not shown). Conclusion: We developed a novel BAFF-R CAR-T cell product structured on single-domain antibody. This product demonstrated promising preclinical activity, and it may provide an alternative choice for patients with B cell malignancies.

Search for New Potential T-Cell and B-Cell Epitopes in the Spike Protein of SARS-CoV-2

The current epidemiological situation, including the existence of new SARS-CoV-2 virus with a high mutagenicity, requires fundamentally new deadlines for the development of vaccines, which may be achieved only applying modern computing technologies and simulation. Epitopes have been found in the spike protein of the SARS-CoV-2 virus using immunoinformatics methods, and their allergenicity and immunogenecity was predicted. It is shown that a vaccine against SARS-CoV-2 can be designed based on these epitopes.