Native Antigen Research Articles

A nanoparticle vaccine displaying the ookinete PSOP25 antigen elicits transmission-blocking antibody response against Plasmodium berghei

BackgroundSafe and effective vaccines are crucial for the control and eventual elimination of malaria. Novel approaches to optimize and improve vaccine efficacy are urgently required. Nanoparticle-based delivery platforms are considered potent and powerful tools for vaccine development.MethodsIn this study, we developed a transmission-blocking vaccine against malaria by conjugating the ookinete surface antigen PSOP25 to the Acinetobacter phage coat protein AP205, forming virus-like particles (VLPs) using the SpyTag/SpyCatcher adaptor system. The combination of AP205-2*SpyTag with PSOP25-SpyCatcher resulted in the formation of AP205-PSOP25 complexes (VLP-PSOP25). The antibody titers and avidity of serum from each immunization group were assessed by ELISA. Western blot and IFA were performed to confirm the specific reactivity of the elicit antisera to the native PSOP25 in Plasmodium berghei ookinetes. Both in vitro and in vivo assays were conducted to evaluate the transmission-blocking activity of VLP-PSOP25 vaccine.ResultsImmunization of mice with VLP-PSOP25 could induced higher levels of high-affinity antibodies than the recombinant PSOP25 (rPSOP25) alone or mixtures of untagged AP205 and rPSOP25 but was comparable to rPSOP25 formulated with alum. Additionally, the VLP-PSOP25 vaccine enhanced Th1-type immune response with remarkably increased levels of IgG2a subclass. The antiserum generated by VLP-PSOP25 specifically recognizes the native PSOP25 antigen in P. berghei ookinetes. Importantly, antisera generated by inoculation with the VLP-PSOP25 could inhibit ookinete development in vitro and reduce the prevalence of infected mosquitoes or oocyst intensity in direct mosquito feeding assays.ConclusionsAntisera elicited by immunization with the VLP-PSOP25 vaccine confer moderate transmission-reducing activity and transmission-blocking activity. Our results support the utilization of the AP205-SpyTag/SpyCatcher platform for next-generation TBVs development.Graphical abstract

Evaluation of Hydatid Cyst Antigen for Serological Diagnosis.

Hydatidosis, a chronic zoonotic disease, has a distribution worldwide and is caused by the larval stage of the Echinococcus helminth. The Dot-ELISA test can diagnose hydatidosis quickly and accurately. Additionally, unlike other hydatid disease tests now used, this quick and affordable enzyme immunoassay is very serum-conservative and antigen-conservative, needing just nanogram levels of parasite antigen. In the present cross-sectional study, crude and B antigens of hydatid cyst fluid were obtained to diagnose human hydatidosis using CIEP (Counter Immunoelectrophoresis), ELISA (Enzyme-linked Immuno Sorbent assay), and Dot- ELISA (Dot Enzyme linked Immuno Sorbent Assay) methods. Infected liver with a hydatid cyst was collected from Tehran's slaughterhouses to prepare cyst fluid in different stages. After extracting and purifying the Cyst fluid, it is centrifuged at 4ºc, then prepared to concentrate. The study also included sera from hydatidosis (n=60), samples of helminth parasites (n=55), fascioliasis (n=35), toxocariasis (n=20) and negative control (n=35) were tested by CIEP (Counter Immunoelectrophoresis), ELISA (Enzyme-linked Immune Sorbent assay), and Dot- ELISA (Dot Enzyme linked Immuno Sorbent Assay) methods. All statistical analyses were performed using Statistical Package for the Social Sciences (SPSS) for Windows release 25.0 (SPSS Inc., Chicago, IL, USA). Crude antigen of hydatid cyst showed a specificity of 76.7%, a sensitivity of 93.3% using the ELISA method, and B antigen showed a specificity of 96.7% and sensitivity of 88.3% using the same method. The crude antigen of the hydatid cyst exhibited a specificity of 68.9% and a sensitivity of 86.7% using CIEP. The B antigen showed a specificity of 87.8% and sensitivity of 83.3% using the same method.The crude antigen of hydatid cyst having serum dilution at 1:800 exhibited a specificity of 83.3% and sensitivity of 100% using the Dot-ELISA method and B antigen having serum dilution at 1:800 serum showed a specificity of 100% and sensitivity of 98.3% using the same method. The results of this finding showed that B antigen has the maximum specificity to diagnose hydatid test using the Dot- ELISA method. Hydatid cysts present with varied symptomatology. History of exposure to infected animals may not be present. A high degree of clinical suspicion combined with meticulous history and clinical examination supported by laboratory investigations are required for its diagnosis. The Dot-ELISA system with native antigen B is a viable approach for the immunodiagnosis of human hydatidosis that is preferred to infection.

The Human Cytomegalovirus Latency-Associated Gene Product Latency Unique Natural Antigen Regulates Latent Gene Expression.

Human cytomegalovirus (HCMV) infection can lead to either lytic or latent infection, which is dependent on the regulation of the viral major immediate early promoter (MIEP). Suppression of the MIEP is a pre-requisite for latency and is driven by repressive epigenetic modifications at the MIEP during latent infection. However, other viral genes are expressed during latency and this is correlated with activatory epigenetic modifications at latent gene promoters. Yet the molecular basis of the differential regulation of latent and lytic gene expression by epigenetics is unclear. LUNA, a latent viral transcript, has been suggested to be important for HCMV latency and has also been shown to be important for efficient reactivation likely through its known deSUMOylase activity. Intriguingly, we and others have also observed that LUNA enhances latency-associated expression of the viral UL138 gene. Here, we show that in the absence of LUNA, the expression of multiple latency-associated transcripts is reduced during latent infection, which is correlated with a lack of activatory marks at their promoters. Interestingly, we also show that LUNA interacts with the hematopoietic transcription factor GATA-2, which has previously been shown to bind to a number of latency-associated gene promoters, and that this interaction is dependent on the deSUMOylase domain of LUNA. Finally, we show that the deSUMOylase activity of LUNA is required for the establishment and/or maintenance of an open chromatin configuration around latency-associated gene promoters. As such, LUNA plays a key role in efficient latency-associated viral gene expression and carriage of viral genome during latent carriage.

O-110 - Coexpression of natural killer cell antigens by T-cell large granular lymphocytes in hydroa vacciniforme lymphoproliferative disorder and the involvement of Vδ1+ epithelial-type γδT cells

O-110 - Coexpression of natural killer cell antigens by T-cell large granular lymphocytes in hydroa vacciniforme lymphoproliferative disorder and the involvement of Vδ1+ epithelial-type γδT cells

Serological diagnosis of fasciolosis (Fasciola hepatica) in humans, cattle, and sheep: a meta-analysis.

Fasciola hepatica can cause problems in both animals and humans. Fasciolosis can be diagnosed through the indirect ELISA immunodiagnostic test. Serological diagnosis of Fasciola is based on recombinant antigens secreted by this worm. We used PubMed and Google Scholar databases to review the published literature on 'antigens with immunogenic potential' used in serological tests to identify antibodies against F. hepatica in humans, cattle, and sheep. Studies that investigated diagnostic tests with common reference standards were included in the sensitivity and/or specificity bivariate meta-analysis. In the quality and susceptibility to bias analysis of the 33 included studies, 26 fulfilled at least six (75%) of the eight QUADAS criteria and were considered good-quality papers. We found that most of the studies used native excretory-secretory antigens and recombinant cathepsin in ELISA tests for serological diagnosis of fascioliasis in humans, cattle, and sheep. The meta-analysis revealed that all antigens demonstrated good accuracy. The best results in terms of sensitivity [0.931-2.5% confidence interval (CI) and 0.985-97.5% CI] and specificity (0.959-2.5% CI and 0.997-97.5% CI) were found in human FhES. FhrCL-1, FhES, and FhrSAP-2 antigens gave the best results for the serum diagnosis of human and animal fasciolosis.

Immunological profile of mice immunized with a polyvalent virosome-based influenza vaccine

BackgroundInfluenza A virus (IAV) causes respiratory disease in pigs and is a major concern for public health. Vaccination of pigs is the most successful measure to mitigate the impact of the disease in the herds. Influenza-based virosome is an effective immunomodulating carrier that replicates the natural antigen presentation pathway and has tolerability profile due to their purity and biocompatibility.MethodsThis study aimed to develop a polyvalent virosome influenza vaccine containing the hemagglutinin and neuraminidase proteins derived from the swine IAVs (swIAVs) H1N1, H1N2 and H3N2 subtypes, and to investigate its effectiveness in mice as a potential vaccine for swine. Mice were immunized with two vaccine doses (1 and 15 days), intramuscularly and intranasally. At 21 days and eight months later after the second vaccine dose, mice were euthanized. The humoral and cellular immune responses in mice vaccinated intranasally or intramuscularly with a polyvalent influenza virosomal vaccine were investigated.ResultsOnly intramuscular vaccination induced high hemagglutination inhibition (HI) titers. Seroconversion and seroprotection (> 4-fold rise in HI antibody titers, reaching a titer of ≥ 1:40) were achieved in 80% of mice (intramuscularly vaccinated group) at 21 days after booster immunization. Virus-neutralizing antibody titers against IAV were detected at 8 months after vaccination, indicating long-lasting immunity. Overall, mice immunized with the virosome displayed greater ability for B, effector-T and memory-T cells from the spleen to respond to H1N1, H1N2 and H3N2 antigens.ConclusionsAll findings showed an efficient immune response against IAVs in mice vaccinated with a polyvalent virosome-based influenza vaccine.

Optimization of an alum-anchored clinical HIV vaccine candidate

In the ongoing effort to develop a vaccine against HIV, vaccine approaches that promote strong germinal center (GC) responses may be critical to enable the selection and affinity maturation of rare B cell clones capable of evolving to produce broadly neutralizing antibodies. We previously demonstrated an approach for enhancing GC responses and overall humoral immunity elicited by alum-adjuvanted protein immunization via the use of phosphoserine (pSer) peptide-tagged immunogens that stably anchor to alum particles via ligand exchange with the alum particle surface. Here, using a clinically relevant stabilized HIV Env trimer termed MD39, we systematically evaluated the impact of several parameters relevant to pSer tag composition and trimer immunogen design to optimize this approach, including phosphate valency, amino acid sequence of the trimer C-terminus used for pSer tag conjugation, and structure of the pSer tag. We also tested the impact of co-administering a potent saponin/monophosphoryl lipid A (MPLA) nanoparticle co-adjuvant with alum-bound trimers. We identified MD39 trimer sequences bearing an optimized positively-charged C-terminal amino acid sequence, which, when conjugated to a pSer tag with four phosphates and a polypeptide spacer, bound very tightly to alum particles while retaining a native Env-like antigenicity profile. This optimized pSer-trimer design elicited robust antigen-specific GC B cell and serum IgG responses in mice. Through this optimization, we present a favorable MD39-pSer immunogen construct for clinical translation.

Immunodiagnostic Detection of Angiostrongylus cantonensis Exposure on Hawaii Island Using Isogeographic 31-kDa Antigen.

Angiostrongylus cantonensis is the leading cause of neuroangiostrongyliasis worldwide, and east Hawaii Island is a hotspot for the disease in the United States. A combination of glycoproteins with molecular weight of 31 kDa has been used as antigen to evaluate antibody response in human serum samples in Thailand with high specificity and sensitivity. In a previous pilot study, the Thailand-isolated 31-kDa proteins showed efficacy in dot-blot tests using serum samples from 435 human volunteers on Hawaii Island. However, we hypothesized that native antigen isolated from Hawaii A. cantonensis may exhibit higher specificity than the Thailand-isolated 31-kDa antigen due to potential minor variation in epitopes between isolates. In this study, 31-kDa glycoproteins were isolated by sodium dodecyl-sulfate polyacrylamide gel electrophoresis from adult A. cantonensis nematodes collected from rats captured on east Hawaii Island. The resultant proteins were purified by electroelution, pooled, bioanalyzed, and quantified. A subset of 148 samples from human participants of the original cohort of 435 was consented for this study, including 12 of the original 15 clinically diagnosed participants. Results of ELISA using the Hawaii-isolated 31-kDa antigen were compared with results of the same serum samples previously tested with both crude Hawaii antigen ELISA and Thailand 31-kDa antigen dot blot. This study shows a seroprevalence in the general population of East Hawaii Island of 25.0%, similar to previous findings of 23.8% seroprevalence in this cohort using crude antigen from Hawaii A. cantonensis and 26.5% using Thailand 31-kDa antigen.

Functional of tongue sole (Cynoglossus semilaevis) gamma-interferon-inducible lysosomal thiol reductase with implications in innate immune reponse depend on CXXC active site

The enzyme gamma-interferon-inducible lysosomal thiol reductase (GILT) plays an important role in promoting the processing and presentation of major histocompatibility complex (MHC) class II-restricted antigens. It is also involved in MHC I-restricted antigens catalyzing disulfide bond reduction in fishes’ adaptive immunity. The open reading frame of tongue sole (Cynoglossus semilaevis) GILT (tsGILT) gene is 771 bp long, encoding 257 amino acids, with a calculated molecular weight of 28.465 kDa and isoelectric point (pI) of 5.35. After induction with lipopolysaccharide, the expression of tsGILT mRNA was upregulated in spleen and kidney and recombinant tsGILT protein transferred to late endosomes and lysosomes in HeLa cells. The refolded tsGILT was capable of catalyzing the reduction of the interchain disulfide bonds against an IgG substrate depend on the active site CXXC motif at residues 75–78. The process of immune response to bacteria challenge needs GILT to catalyze the reduction of disulfide bond and unfolding native protein antigens, promoting their hydrolysis by proteases. Whether a single mutation or a double mutation of active site CXXC at residues75–78, the 3D structure of tsGILT protein has undergone major changes and lost its activity of catalyzing the reduction of the interchain disulfide bonds.

Identification of Eimeria tenella sporozoite immunodominant mimotopes by random phage-display peptide libraries-a proof of concept study.

Coccidiosis, caused by parasites of numerous Eimeria species, has long been recognized as an economically significant disease in the chicken industry worldwide. The rise of anti-coccidian resistance has driven a search for other parasite management techniques. Recombinant antigen vaccination presents a highly feasible alternative. Properly identifying antigens that might trigger a potent immune response is one of the major obstacles to creating a viable genetically modified vaccine. This study evaluated a reverse immunology approach for the identification of B-cell epitopes. Antisera from rabbits and hens inoculated with whole-sporozoites of E. tenella were used to identify Western blot antigens. The rabbit IgG fraction from the anti-sporozoite serum exhibited the highest reactogenicity; consequently, it was purified and utilized to screen two random Phage-display peptide libraries (12 mer and c7c mer). After three panning rounds, 20 clones from each library were randomly selected, their nucleotide sequences acquired, and their reactivity to anti-sporozoite E. tenella serum assessed. The selected peptide clones inferred amino acid sequences matched numerous E. tenella proteins. The extracellular domain of the epidermal growth factor-like (EGF-like) repeats, and the thrombospondin type-I (TSP-1) repeats of E. tenella micronemal protein 4 (EtMIC4) matched with the c7c mer selected clones CNTGSPYEC (2/20) and CMSTGLSSC (1/20) respectively. The clone CSISSLTHC that matched with a conserved hypothetical protein of E. tenella was widely selected (3/20). Selected clones from the 12-mer phage display library AGHTTQFNSKTT (7/20), GPNSAFWAGSER (2/20) and HFAYWWNGVRGP (8/20) showed similarities with a cullin homolog, elongation factor-2 and beta-dynein chain a putative E. tenella protein, respectively. Four immunodominant clones were previously selected and used to immunize rabbits. By ELISA and Western blot, all rabbit anti-clone serums detected E. tenella native antigens. Thus, selected phagotopes contained recombinant E. tenella antigen peptides. Using antibodies against E. tenella sporozoites, this study demonstrated the feasibility of screening Phage-display random peptide libraries for true immunotopes. In addition, this study looked at an approach for finding novel candidates that could be used as an E. tenella recombinant epitope-based vaccine.

Application and evaluation of native antigen B from Echinococcus granulosus sensu stricto and E. canadensis alone or mixture for serodiagnosis of human G1-G3 and G6/G7 genotypes cystic echinococcosis sera, using ELISA and Western blotting.

Cystic echinococcosis (CE) is one of the most important helminthic diseases in the world with different genotypes distribution. The application of specific genotype antigens together with sera from patients with specific cyst genotypes have not been reported, so far. The present study aimed to apply and evaluate native AgB from Echinococcus granulosus sensu stricto (Eg) and Echinococcus canadensis (Ec) alone or mixture for serodiagnosis of human G1-G3 and G6/G7 genotypes cystic echinococcosis sera, using ELISA and Western blotting. A total of 47 human sera along with 47 human CE cysts were collected. CE genotypes were determined. Native AgB were prepared from E. granulosus s.s and E. canadensis genotypes. ELISA and Western blot were performed on human specific G1-G3 and G6/G7 genotypes sera. Species specific native AgB were used alone or mixed. The sensitivity of ELISA using alone and mixed 1Eg-1Ec, 1Eg-2Ec, and 2Eg-1Ec of native AgB from E. granulosus s.s and E. canadensis genotypes for human G1-G3 sera were 92.10, 89.47, 97.37, 100, and 100%, respectively; while using AgBs, alone and mixed for human G6/G7 sera were 100%. The sensitivity of Western blotting using native AgB of E. granulosus s.s and E. canadensis genotypes alone and mixed 2Eg-1Ec were 78.95% and 100% for human G1-G3 and G6/G7 genotypes sera, respectively. The mixture of AgB from Echinoccus granulosus sensu stricto and Echinococcus canadensis genotypes increased ELISA sensitivity for the diagnosis of human CE. Preparation and application of native AgB from specific and prevalent genotypes of CE in endemic regions is recommended.

Harnessing Autophagy to Overcome Antigen-Specific T-Cell Dysfunction: Implication for People Living with HIV-1.

Like other chronic viral infections, HIV-1 persistence inhibits the development of antigen-specific memory T-cells, resulting in the exhaustion of the immune response and chronic inflammation. Autophagy is a major lysosome-dependent mechanism of intracellular large-target degradation such as lipid and protein aggregates, damaged organelles, and intracellular pathogens. Although it is known that autophagy may target HIV-1 for elimination, knowledge of its function as a metabolic contributor in such viral infection is only in its infancy. Recent data show that elite controllers (EC), who are HIV-1-infected subjects with natural and long-term antigen (Ag)-specific T-cell protection against the virus, are characterized by distinct metabolic autophagy-dependent features in their T-cells compared to other people living with HIV-1 (PLWH). Despite durable viral control with antiretroviral therapy (ART), HIV-1-specific immune dysfunction does not normalize in non-controller PLWH. Therefore, the hypothesis of inducing autophagy to strengthen their Ag-specific T-cell immunity against HIV-1 starts to be an enticing concept. The aim of this review is to critically analyze promises and potential limitations of pharmacological and dietary interventions to activate autophagy in an attempt to rescue Ag-specific T-cell protection among PLWH.

Charging CAR by electrostatic power.

Chimeric antigen receptor (CAR)-T cell therapy has emerged as a promising approach for cancer treatment. CAR is a synthetic immune receptor that recognizes tumor antigen and activates T cells through multiple signaling pathways. However, the current CAR design is not as robust as T cell receptor (TCR), a natural antigen receptor with high sensitivity and efficiency. TCR signaling relies on specific molecular interactions, and thus electrostatic force, the major force of molecular interactions, play critical roles. Understanding how electrostatic charge regulates TCR/CAR signaling events will facilitate the development of next-generation T cell therapies. This review summarizes recent findings on the roles of electrostatic interactions in both natural and synthetic immune receptor signaling, specifically that in CAR clustering and effector molecule recruitments, and highlights potential strategies for engineering CAR-T cell therapy by leveraging charge-based interactions.

Generation of a monoclonal antibody against duck circovirus capsid protein and its potential application for native viral antigen detection.

Duck circovirus (DuCV) infection is currently recognized as an important immunosuppressive disease in commercial duck flocks in China. Specific antibodies against DuCV viral proteins are required to improve diagnostic assays and understand the pathogenesis of DuCV infection. To generate DuCV-specific monoclonal antibodies (mAbs), a recombinant DuCV capsid protein without the first 36 N-terminal amino acids was produced in Escherichia coli. Using the recombinant protein as an immunogen, a mAb was developed that reacted specifically with the DuCV capsid protein, expressed in E. coli and baculovirus systems. Using homology modeling and recombinant truncated capsid proteins, the antibody-binding epitope was mapped within the region of 144IDKDGQIV151, which is exposed to solvent in the virion capsid model structure. To assess the applicability of the mAb to probe the native virus antigen, the murine macrophage cell line RAW267.4 was tested for DuCV replicative permissiveness. Immunofluorescence and Western blot analysis revealed that the mAb recognized the virus in infected cells and the viral antigen in tissue samples collected from clinically infected ducks. This mAb, combined with the in vitro culturing method, would have widespread applications in diagnosing and investigating DuCV pathogenesis.

Disseminated Extranodal NK/T-Cell lymphoma, Presenting as an Orbital Mass.

An 84-year-old male patient presented with decreased vision of 20/300 in the right eye, with additional painless upper eyelid fullness, hypoglobus, severe limitation of ocular motility, and conjunctival chemosis of the right eye for several months duration (panel A). He was referred after failing to respond to a trial of oral corticosteroids for presumed orbital myositis. MRI revealed an enlarged enhancing lacrimal gland (arrow), extraocular muscles, and mucosal thickening of the ethmoid sinus (arrowhead) on the right side (panel B). Lacrimal gland biopsy demonstrated medium-sized atypical lymphocytes with irregular nuclear contours, scant-to-moderate amounts of cytoplasm, and brisk mitotic figures (arrow) (panel C, hematoxylin-eosin, ×630), which expressed cytotoxic and natural killer-cell markers CD56 (panel D, ×400), perforin, and T-cell intracellular antigen 1, and were CD4-positive and CD8-negative. Neoplastic cells were positive for Epstein–Barr virus-encoded RNA by in situ hybridization (panel E, ×400). Clinical, morphologic, and immunophenotypic findings were compatible with extranodal natural killer/T-cell lymphoma (natural killer/T-cell lymphoma, nasal type). Optical coherence tomography revealed diffuse choroidal thickening with an undulating anterior border (sea-sick choroid) (arrow), compatible with choroidal involvement by lymphoma (panel F). Positron emission tomography scan showed significantly increased activity in the regional and distal lymph nodes and in multiple bones, compatible with disseminated disease. The patient succumbed to disease shortly after diagnosis. This case highlights the importance of prompt and accurate diagnosis of natural killer/T-cell lymphoma, nasal type, which can present with orbital and ocular involvement simulating an inflammatory process.FIG

Transcriptome analysis of Chinese sucker (Myxocyprinus asiaticus) head kidney and discovery of key immune-related genes to cold stress after swimming fatigue

For Chinese sucker (Myxocyprinus asiaticus), passing through a dam with fast flow and cold water are always unavoidable, and this process can cause stress, disease or even death. In this study, comparative transcriptome analysis was conducted to investigate the potential immune mechanism in head kidney of M. asiaticus with swimming fatigue stress and cold stress after fatigue. In general, a total of 181,781 unigenes were generated, and 38,545 differentially expressed genes (DEGs) were identified. In these DEGs, 22,593, 7286 and 8666 DEGs were identified among groups of fatigue vs. cold, control vs. cold, and control vs. fatigue, respectively. Enrichment analysis revealed these DEGs were involved in coagulation cascades and complement, natural killer cell mediated cytotoxicity, antigen processing and presentation, Toll-like receptor signaling pathways, and chemokine signaling pathway. Notably, immune genes including heat shock protein 4a (HSP4a), HSP70 and HSP90α genes were significantly up-regulated in fishes with cold stress after fatigue. Differently, more immune genes in control vs. cold compared with that in control vs. fatigue were significantly down-regulated expression, such as claudin-15-like, Toll-like receptor 13, antimicrobial peptide (hepcidin), immunoglobulin, CXCR4 chemokine receptor, T-cell receptor, complement factor B/C2-A3, and interleukin 8. In this study, the number of DEGs in the head kidney was less than that our previous study in the spleen, which we speculated was more sensitive to changes in water temperature than the head kidney. In summary, lots of immune-related genes in the head kidney were down-regulated under cold stress after fatigue, suggesting that M. asiaticus might have experienced severe immunosuppression in the process of passing through the dam.

STUDYING THE DIAGNOSTIC VALUE OF RECOMBINANT CAMPYLO-BACTER JEJUNI ANTIGENS

This article describes the results of a study on the diagnostic value of Campylobacter jejuni recombinant antigens, Campylobacter Omp18 protein and major outer membrane protein (MOMP). In the present study, these proteins were used as antigens in enzyme im-munoassays to detect specific antibodies in the serum of cattle. Commercial native protein antigens were used to compare the effectiveness with similar studies. In total, 95 blood se rum samples from cattle from various farms in the northern region of the Republic of Ka-zakhstan were used. The greatest number of positive results was observed when using a commercial native antigen (52.6%); 47.4% of sera reacted positively with respect to the Omp18 antigen, and 38.9% with respect to the MOMP antigen. Statistical analysis revealed a high correlation between the native and Omp18 antigens and, to a lesser extent, with MOMP32. Because native antigens contain many different cell-wall proteins, they are less specific. Therefore, for serological diagnosis of cattle using enzyme immunoassays, it is ad-visable to use the C. jejuni outer membrane recombinant antigen MOMP32, as it has valua-ble diagnostic properties.

Therapy targeting antigen-specific T cells by a peptide-based tolerizing vaccine against autoimmune arthritis

A longstanding goal has been to find an antigen-specific preventive therapy, i.e., a vaccine, for autoimmune diseases. It has been difficult to find safe ways to steer the targeting of natural regulatory antigen. Here, we show that the administration of exogenous mouse major histocompatibility complex class II protein bounding a unique galactosylated collagen type II (COL2) peptide (Aq-galCOL2) directly interacts with the antigen-specific TCR through a positively charged tag. This leads to expanding a VISTA-positive nonconventional regulatory T cells, resulting in a potent dominant suppressive effect and protection against arthritis in mice. The therapeutic effect is dominant and tissue specific as the suppression can be transferred with regulatory T cells, which downregulate various autoimmune arthritis models including antibody-induced arthritis. Thus, the tolerogenic approach described here may be a promising dominant antigen-specific therapy for rheumatoid arthritis, and in principle, for autoimmune diseases in general.

A Plant-Derived Maternal Vaccine against Porcine Epidemic Diarrhea Protects Piglets through Maternally Derived Immunity.

Newborn piglets are susceptible to a highly contagious enteritis caused by the porcine epidemic diarrhea virus (PEDV), associated with high levels of mortality worldwide. There is pressing need for a rapid, safe, and cost-effective vaccine to safeguard pigs from getting infected by PEDV. PEDV belongs to the coronavirus family and is characterized by high levels of mutability. The primary goal of a PEDV vaccine is to provide immunity to newborn piglets through vaccination of sows. Plant-based vaccines are becoming more popular because they have low manufacturing costs, are easily scalable, have high thermostability, and a long shelf life. This is in contrast to conventional vaccines which include inactivated, live, and/or recombinant types that can be expensive and have limited ability to respond to rapidly mutating viruses. The binding of the virus to host cell receptors is primarily facilitated by the N-terminal subunit of the viral spike protein (S1), which also contains several epitopes that are recognized by virus-neutralizing antibodies. As a result, we generated a recombinant S1 protein using a plant-based vaccine platform. We found that the recombinant protein was highly glycosylated, comparable to the native viral antigen. Vaccination of pregnant sows at four and two weeks before farrowing led to the development of humoral immunity specific to S1 in the suckling piglets. In addition, we noted significant viral neutralization titers in both vaccinated sows and piglets. When challenged with PEDV, piglets born from vaccinated sows displayed less severe clinical symptoms and significantly lower mortality rates compared to piglets born from non-vaccinated sows.

Coexpression of natural killer cell antigens by T-cell large granular lymphocytes in hydroa vacciniforme lymphoproliferative disorder and the involvement of Vδ1 + epithelial-type γδT cells

Hydroa vacciniforme lymphoproliferative disorder (HV-LPD) is a cutaneous variant of chronic active Epstein–Barr virus disease. We examined the coexpression of T- and natural killer (NK)-cell antigens in five patients with classic HV (cHV) and five with systemic HV (sHV). T-cell receptor (TCR) repertoire analysis was performed with high‑throughput sequencing. All five cHV patients had increased γδT cells (> 5%), whereas five sHV patients showed γδT- and αβT-cell dominance in two patients each, and a mixture of abnormal γδT and αβT cells in one. Circulating CD3 + T cells expressed CD16/CD56 at 7.8–42.3% and 1.1–9.7% in sHV and cHV, respectively. The percentage of CD16/CD56 + T cells was higher in the large granular lymphocyte or atypical T-cell fractions in sHV, but no TCR Vα24 invariant chain characteristic of NKT cells was detected. Considerable numbers of CD3 + cells expressing CD56 were observed in sHV skin infiltrates. Of the circulating γδT cells tested, TCR Vδ1 + cells characteristic of the epithelial type of γδT cells were dominant in two sHV cases. Thus, atypical αβT and γδT cells in HV-LPD can express NK-cell antigens, such as CD16 and CD56, and Vδ1 + epithelial-type γδT cells are a major cell type in some HV-LPD cases.