Group Antigens Research Articles

IL-18R supported CAR T cells targeting oncofetal tenascin C for the immunotherapy of pediatric sarcoma and brain tumors

BackgroundOncofetal splice variants of extracellular matrix (ECM) proteins present a unique group of target antigens for the immunotherapy of pediatric cancers. However, limited data is available if these splice variants...

IMMU-07. THE IMMUNE LANDSCAPE OF PEDIATRIC BRAIN TUMORS: A TRANSCRIPTOMIC ANALYSIS

Abstract Despite standard-of-care therapy, pediatric brain tumors are now the leading cause of cancer-related death in children, highlighting an urgent need for the development of new treatments. Immunotherapy is actively being evaluated as a therapeutic approach to pediatric brain tumors, however, more research is needed to reveal additional antigenic targets that exist in these malignancies. In this study, our team performed a transcriptomic analysis of pediatric brain tumor RNA sequencing data within the Children’s Brain Tumor Network (CBTN) to identify intra and extracellular antigens that are highly expressed across major tumor types. Interestingly, our team observed that most tumors had high gene expression of a group of antigens that were unique to that specific tumor type. Specifically, our analysis revealed that diffuse midline gliomas (DMGs) highly expressed the extracellular antigens CA9, CTCFL, and ST8SIA1, whereas atypical rhabdoid tumors (ATRTs) highly expressed MUC1 and TEK. Other tumors that displayed high gene expression for a variety of antigenic targets included H3-wildtype high-grade gliomas (HGGs), and ependymomas (EPNs). Strikingly, we observed minimal difference in antigen expression in primary tumors when compared to patient-matched recurrences. Beyond antigen expression, we evaluated the expression of antigen processing machinery (APM) which includes major histocompatibility complexes (MHCs). Our findings revealed that DMGs had the lowest level of APM expression, however, these tumors uniquely expressed high levels of the immune checkpoints ADORA2A, CD276, and KLRC1. Contrarily, ATRTs showed a high expression of immune checkpoints CD274 (PD-L1), PVR, and CD80. Other tumors included in our analysis had unique expression patterns of antigen, as well as APM and immune checkpoints. Our findings illustrate that pediatric brain tumors have distinct expression patterns of antigens, APM, and immune checkpoints that are specific to tumor type, emphasizing diverse, rather than general, immunotherapeutic approaches must be considered for childhood brain tumors.

Differences in phenotype between long-lived memory B cells against Plasmodium falciparum merozoite antigens and variant surface antigens.

Plasmodium falciparum infections elicit strong humoral immune responses to two main groups of antigens expressed by blood-stage parasites: merozoite antigens that are involved in the erythrocyte invasion process and variant surface antigens that mediate endothelial sequestration of infected erythrocytes. Long-lived B cells against both antigen classes can be detected in the circulation for years after exposure, but have not been directly compared. Here, we studied the phenotype of long-lived memory and atypical B cells to merozoite antigens (MSP1 and AMA1) and variant surface antigens (the CIDRα1 domain of PfEMP1) in ten Ugandan adults before and after local reduction of P. falciparum transmission. After a median of 1.7 years without P. falciparum infections, the percentage of antigen-specific activated B cells declined, but long-lived antigen-specific B cells were still detectable in all individuals. The majority of MSP1/AMA1-specific B cells were CD95+CD11c+ memory B cells, which are primed for rapid differentiation into antibody-secreting cells, and FcRL5-T-bet- atypical B cells. On the other hand, most CIDRα1-specific B cells were CD95-CD11c- memory B cells. CIDRα1-specific B cells were also enriched among a subset of atypical B cells that seem poised for antigen presentation. These results point to differences in how these antigens are recognized or processed by the immune system and how P. falciparum-specific B cells will respond upon re-infection.

EpiArt: a graphical HLA eplet amino acid repertoire translation reveals the need for an epitope driven revision of allele group nomenclature.

The immune response after transplantation depends on recipient/donor HLA allele mismatches. To enhance our understanding of the relations of HLA alleles in terms of amino-acid polymorphisms and shared epitopes, we assessed pairwise sequence difference between HLA-alleles. We translated amino-acid sequences of confirmed eplets into an atlas of HLA class I and II antigens, followed by visualization of the pairwise allele distances by means of antigen-specific disparity graphs in differential amino-acid space. We obtained an overview of relationships of all alleles of an antigen, corresponding similarity/dissimilarity structures, outliers, alleles with similarity to different antigen groups. Additionally, we calculated prevalence of the amino-acids for each polymorphic sequence position and visualized them in amino-acid motif plots of all alleles belonging to an antigen. Our visualizations show strongly varying intra-group heterogeneity of HLA class I and II alleles, as well as shared inter-group and inter-locus eplets and epitopes, indicating a benefit of epitope-based transplant matching: Single allele recipient/donor mismatches potentially refer to identical eplets, or to a set of multiple mismatched eplets. This data reveals inconsistencies in the HLA group nomenclature and consequently adds a new level of quality to allocation, motivating the definition of tolerable or taboo mismatches.

Genotyping for Weak and Partial D Rh Status to Optimize Usage of Limited Blood Supplies

Abstract Introduction The Rh antigen group, expressed on erythrocytes and encoded by highly polymorphic RHD and RHCE genes on chromosome 1 (1p36-p34), is notable in transfusion medicine due to its high polymorphism, strong immunogenicity and ability to cause hemolytic transfusion reactions in patients and hemolytic disease of the fetus and newborn (HDFN). The D antigen specifically contains multiple epitopes with variations that include decreased expression (weak D) or loss of certain epitopes (partial D) which expose patients to risk of alloimmunization depending on the subtype of the Rh(D) antigen. Hence, serologic weak D testing followed by molecular testing is not performed except for donors testing negative for Rh(D) antigen and newborns typing negative for Rh(D) and born to Rh(D) negative mothers. Given the current shortages of blood supplies, understanding patients’ genotypes in the context of weak or partial D-typing and risk of alloimmunization can be essential in the management of increasingly limited supplies of red blood cell (RBC) units. Objective To further characterize patients that initially type negative for Rh(D) but positive for weak D with molecular testing to investigate risk of alloimmunization, retype the Rh(D) and avoid unnecessary use of Rh(D) negative RBC units during critical shortages of RBC units. Methods We collected the results of ABO/Rh(D) typing for patients with negative Rh(D) testing but positive weak D test over a period of four weeks in December 2023 and had D-variant molecular testing performed by a reference laboratory. Initial serologic ABO/Rh(D) was performed in tube followed by weak D testing by indirect Coombs test in tube. Results The total number of patients who initially tested negative for Rh(D) but positive (weak to +4) for weak-D was three patients. Two patients showed a probable genotype of RHD*01W.1 (RHD* weak type 1, 809T>G (V270G)) homozygous which indicated the presence of weak D+ type 1. Patients with weak D+ type 1 can receive Rh(D) positive red cell units, and they are not at risk of alloimmunization and developing anti-D. The third patient showed a probable genotype RHD*DVI type 2 homozygous (lack of Rh(D) exons 4 through 6) and indicated the presence of partial D antigen. Patients with partial D antigen should receive RH(D) negative red cell units as they are at risk of alloimmunization and developing anti-D. Conclusions Although the vast majority of Transfusion Medicine services do not perform the serologic weak D test with reflex to molecular testing, characterizing patients who test negative with initial serologic Rh(D) testing with serologic and molecular D-tests may aid in retyping the Rh(D) of patients during critical shortages, particularly for patients with ABO blood group O.

Immunogenicity of Brucella Trivalent Immunogen-Containing Polyethyleneimine Nanostructure Targeted with LPS in a Mouse Model.

Brucella is a facultative intracellular gram-negative coccobacillus. It is nonsporulating and reproduced in macrophage phagosomes. The use of nanostructures as drug and vaccine carriers has recently received attention due to their ability to control the release profile and protect the drug molecules. This study presents a suitable nano-polyethyleneimine formulation to be used as an immunoadjuvant and LPS along with trivalent candidate antigens of TF, BP26, and omp31 to selectively stimulate the immune response. After designing and evaluating the immunogenic structure by databases and bioinformatics software, recombinant protein cloning and gene expression were performed in Escherichia coli BL21 bacteria. This protein was extracted from the cultured cells, purified by Ni-NTA column. After placing the antigen inside the polyethyleneimine nanostructure, various properties of the nanoparticles, including their size, zeta potential, and retention rate for injection and inhalation of mice, diffusion efficacy, and antigen binding evaluation were evaluated. Mice were treated with different groups of antigens and nanoparticles on days 0, 10, 24, and 38. Two weeks after the last injection, the level of cytokines were investigated in spleen cells, including IFN-γ, IL-4, and IL-12. The serum concentration of IgG2a and IgG1 antibodies were also assessed. The response was consistent with significant production of IgG1, IgG2a, IFN-γ21, IL-12, and IL-4 compared to the controls (P < 0.05). Compared to the positive and negative control groups, recombinant protein and nanoparticles showed a good response in subsequent injections with live bacterial strains. The present study also revealed the potential of the developed recombinant protein as a candidate in the design and manufacture of subunit vaccines against Brucella species. This protein stimulates cellular and humoral immune responses compared to the positive control groups. These findings can be useful in the prevention and control of brucellosis and pave the way for further research by researchers around the world.

A broad-spectrum vaccine candidate against H5 viruses bearing different sub-clade 2.3.4.4 HA genes

The global spread of H5 clade 2.3.4.4 highly pathogenic avian influenza (HPAI) viruses threatens poultry and public health. The continuous circulation of these viruses has led to their considerable genetic and antigenic evolution, resulting in the formation of eight subclades (2.3.4.4a–h). Here, we examined the antigenic sites that determine the antigenic differences between two H5 vaccine strains, H5-Re8 (clade 2.3.4.4g) and H5-Re11 (clade 2.3.4.4h). Epitope mapping data revealed that all eight identified antigenic sites were located within two classical antigenic regions, with five sites in region A (positions 115, 120, 124, 126, and 140) and three in region B (positions 151, 156, and 185). Through antigenic cartography analysis of mutants with varying numbers of substitutions, we confirmed that a combination of mutations in these eight sites reverses the antigenicity of H5-Re11 to that of H5-Re8, and vice versa. More importantly, our analyses identified H5-Re11_Q115L/R120S/A156T (H5-Re11 + 3) as a promising candidate for a broad-spectrum vaccine, positioned centrally in the antigenic map, and offering potential universal protection against all variants within the clade 2.3.4.4. H5-Re11 + 3 serum has better cross-reactivity than sera generated with other 2.3.4.4 vaccines, and H5-Re11 + 3 vaccine provided 100% protection of chickens against antigenically drifted H5 viruses from various 2.3.4.4 antigenic groups. Our findings suggest that antigenic regions A and B are immunodominant in H5 viruses, and that antigenic cartography-guided vaccine design is a promising strategy for selecting a broad-spectrum vaccine.

The prevalence of erythrocyte alloimmunization in clinical practice: A hospital-based study

Abstract BACKGROUND: One of the complications of blood transfusion is the development of red cell alloimmunization. Little published literature on the prevalence and actual significance of red cell alloantibodies among nonregularly transfused patients and the general population. OBJECTIVES: This study aimed to estimate red cell alloantibodies’ prevalence, specificity, and clinical significance in obstetric and medical practice in Iraq. MATERIALS AND METHODS: A cross-sectional hospital-based study involving internal medicine patients and ladies in obstetric wards of Baghdad Teaching Hospital in Baghdad/Iraq, from January 2022 to May 2022. Demographic data were collected along with detailed medical, obstetric, and transfusion history. Alloantibody screening was performed, and samples with positive results were subjected to antibody titration and identification. RESULTS: A total of 200 patients were enrolled. Indirect antiglobulin test was positive in 15% of patients in internal medicine wards and 23% of ladies in obstetric wards, with most of the identified alloantibodies being clinically significant, against Kidd and Duffy antigen groups. Blood transfusion of more than four units to patients at internal medical wards showed a significant association as a risk for developing red cell alloantibodies (P = 0.025). For ladies in obstetric wards, there was a significant association between pregnancy loss at the time of screening and alloimmunization (P = 0.0164). CONCLUSION: High prevalence of red cell alloantibodies in comparison to what is published worldwide. Transfusion of more than four units of blood and pregnancy loss at the time of screening were statistically significant risks for alloimmunization of the medical and obstetric populations, respectively.

TCR clustering by contrastive learning on antigen specificity.

Effective clustering of T-cell receptor (TCR) sequences could be used to predict their antigen-specificities. TCRs with highly dissimilar sequences can bind to the same antigen, thus making their clustering into a common antigen group a central challenge. Here, we develop TouCAN, a method that relies on contrastive learning and pretrained protein language models to perform TCR sequence clustering and antigen-specificity predictions. Following training, TouCAN demonstrates the ability to cluster highly dissimilar TCRs into common antigen groups. Additionally, TouCAN demonstrates TCR clustering performance and antigen-specificity predictions comparable to other leading methods in the field.

Streptococcus suis subsp. hashimotonensis subsp. nov.: Lancefield group A antigen–positive organisms isolated from human clinical specimens and wild boar oral cavity samples

Three Streptococcus suis-like strains positive for Lancefield antigen group A were isolated from human boar bite wounds and the oral cavities of boars in Hashimoto City, Wakayama Prefecture, Japan, and their taxonomic positions were investigated. Application of the VITEK2 system identified all three isolates as S. suis with > 94 % probability. The isolates were assigned to S. suis based on the results of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis (Biotyper score of 2.382) but were differentiated according to the characteristic signal peaks (4709 m/z and 9420 m/z) that were not present for S. suis. Sequence analysis of the 16S rRNA and sodA genes determined that the isolates were similar to S. suis; however, these genes appeared on a phylogenetic sub-branch. Phylogenetic analysis of the whole chromosomal DNA showed that the isolate formed a cluster with S. suis but with clear divergence. The average nucleotide index using BLAST between the clinical isolate (PAGU 2482) and a closely related reference strain of S. suis was 94.75 %, which was not clearly conclusive; however, digital DNA-DNA hybridization showed a value of 61.2 %. Biochemical reactions, including those with acid phosphatase, α-chymotrypsin, and tagatose (acidification), distinguished our isolates from S. suis. Thus, based on phylogenetic, genomic, and phenotypic characteristics and MALDI-TOF-MS signal patterns, we propose that the isolate with Lancefield group A positive characteristics be designated as a novel subspecies, Streptococcus suis subsp. hashimotonensis subsp. nov., with the type strain PAGU 2482T (GTC 18290T = CCUG 77434T).

Identification of broad-spectrum B-cell and T-cell epitopes of H9 subtype avian influenza virus HA protein using polypeptide scanning1

The H9N2 subtype avian influenza virus (AIV) hemagglutinin (HA) protein is a major immunogen in which HA1 is a genetic variant and HA2 is relatively conserved. Identifying broad-spectrum antigen epitopes targeting HA1 is crucial for vaccine design and detection. Based on the phylogenetic and serological analyses, we identified 2 antigenic groups and 3 representative viruses: A/chicken/Jiangsu/JY040218C/2019, A/pigeon/Jiangsu/JY020616/2019, and A/chicken/Jiangsu/WX090312/2018. An overlapping peptide library was synthesized using HA1 amino acid sequences of the viruses as templates. Through peptide scanning of the sera against different strains of H9N2 subtype AIV, we identified peptides from 4 regions (H9-2/3, H9-20/21, H9-26, and H9-29/30/31) that demonstrated broad-spectrum reactivity. Immunological assay results demonstrated that H9-21 (219RIFKPLIGPRPLVNGLMGRI239), H9-26 (269SGESHGRILKTDLKMGSCTV289), and H9-30 (309YAFGNCPKYI GVKSLKLAVG329) effectively induced antibody generation and conferred partial protective efficacy against the parent virus JY040218C. The results of lymphocyte proliferation and ELISpot assays indicated that peptides H9-15 (159MRWLTQKNNAYPTQDAQYTN179), H9-22 (229PLVNGLMGRINYYWSVLKP G249), and H9-23 (239NYYWSVLKPGQTLRIKSDGN259) could effectively stimulate the expression of interferon-gamma in peripheral blood lymphocytes of chickens immunized against different strains of H9N2 AIV. Collectively, 5 novel cell epitopes H9-15, H9-22, H9-23, H9-26, and H9-30, including the best B cell epitope H9-26 and the best T cells epitope H9-22, were identified that could be targeted for vaccine design or detection approaches against H9N2 AIVs.

Increased levels of IL-4 in the Spleen of BALB/c Mice after 65.5 kDa Pili Protein Klebsiella pneumoniae Immunization

Pneumonia is an infection of the lung parenchyma caused by Klebsiella pneumoniae, resulting in a high mortality rate of millions each year. To reduce these deaths, one potential solution is to create a vaccine that utilizes virulence factors of this microorganism, such as pili. During the early phase of infection, these antigens have a crucial role and can stimulate the production of memory b cells. These cells are activated by IL-4 (interleukin-4) in lymphoid organs, such as the spleen. Pathogen exposure such as virulence factors can stimulate the secretion of IL-4 in the spleen organ. This study aims to investigate the role of Klebsiella pneumoniae pili in this process. The research conducted from May to December 2023 at the Microbiology Laboratory, Faculty of Medicine, University of Jember was purely experimental, using Balb/c mice with IL-4 levels in the spleen organ as variables. The study used 15 mice, divided into control (K1), adjuvant (K2), and antigen (K3) groups. The research data were analyzed using non-parametric tests, specifically the Kruskal-Wallis and Post Hoc tests. The Kruskal-Wallis test revealed significant differences (p=0.003). In the Post Hoc test, a significant difference was found between the control and antigen groups (p=0.002). The results conclusively demonstrate that induction of Klebsiella pneumoniae pili protein 65.5 kDa significantly increases IL-4 levels in the spleen. Future studies should consider adding serum specimens to provide additional information.

Differences in phenotype between long-lived memory B cells against Plasmodium falciparum merozoite antigens and variant surface antigens.

Plasmodium falciparum infections elicit strong humoral immune responses to two main groups of antigens expressed by blood-stage parasites: merozoite antigens that are involved in the erythrocyte invasion process and variant surface antigens that mediate endothelial sequestration of infected erythrocytes. Long-lived B cells against both antigen classes can be detected in the circulation for years after exposure, but have not been directly compared. Here, we studied the phenotype of long-lived memory and atypical B cells to merozoite antigens (MSP1 and AMA1) and variant surface antigens (the CIDRα1 domain of PfEMP1) in Ugandan adults before and after local reduction of P. falciparum transmission. After a median of 1.7 years without P. falciparum infections, the percentage of antigen-specific activated B cells declined, but long-lived antigen-specific B cells were still detectable in all individuals. The majority of MSP1/AMA1-specific B cells were CD95+CD11c+ memory B cells, which are primed for rapid differentiation into antibody-secreting cells, and FcRL5-T-bet- atypical B cells. On the other hand, most CIDRα1-specific B cells were CD95-CD11c- memory B cells. CIDRα1-specific B cells were also enriched among a subset of atypical B cells that seem poised for antigen presentation. These results point to differences in how these antigens are recognized or processed by the immune system and how P. falciparum-specific B cells will respond upon re-infection.

A rapid strategy to develop personalized cancer nanovaccines for different immunogenic tumors.

e14670 Background: Therapeutic cancer vaccines aim to train the immune system and elicit antitumor immune responses, which are expected to fill the unmet medical need of immune checkpoint inhibitors. Despite tremendous efforts over the past decades, it remains challenging to prepare personalized cancer vaccines using a facile and rapid approach due to tumor diversity. CpG-ODN is a promising immunoadjuvant in cancer immunotherapy, and many clinical trials have been performed or are ongoing. However, commonly used phosphorothioate-modified CpG ODN easily induces protein aggregation and its long-term side effects are concerned. Here, we designed hollow large-pore mesoporous organosilica with sulfide bond to simultaneously load unmodified CpG-ODN with guanine-quadruplex (G4) structures and different tumor antigens to prepare personalized cancer vaccines in a simple, fast, and effective way. Methods: High-immunogenicE.G7-OVA lymphoma or low-immunogenic Lewis lung carcinoma (LLC) cells were subcutaneously inoculated into the left flanks to establish tumor-bearing mice. On days 4, 7, and 10 post tumor inoculation, cancer vaccines prepared using model antigen (OVA) or autologous tumor antigen (LLC tumor cell lysate) were subcutaneously injected into the right flanks of mice, respectively. Saline group, free tumor antigen group, free tumor antigen + CpG-ODN group, tumor antigen + organosilica group were used as controls. The size of tumors was monitored. Results: Cancer vaccines against E.G7-OVA showed high loading efficiencies of &gt;95% for both CpG-ODN and OVA, triggered antitumor immune response with high percentages of CD4+, CD8+, tetramer+CD8+ T cells in splenocytes, and effectively inhibited the growth of established tumor, compared with free OVA, free OVA + CpG-ODN, free OVA + organosilica groups. Cancer vaccines against LLC exhibited high loading efficiencies of &gt;95% and &gt;80% for CpG-ODN and LLC tumor cell lysate, activated antitumor immune response with high percentages of CD4+ and CD8+ T cells in splenocytes and CD8+ T, NK and M1 cells in tumor sites, and effectively inhibited the growth of established tumor, compared with control groups. Conclusions: Codelivery of CpG-ODN and different tumor antigens using hollow large-pore mesoporous organosilica elicits antitumor immunity against both high-immunogenic and low-immunogenic tumors.

The antigenic landscape of human influenza N2 neuraminidases from 2009 until 2017.

Human H3N2 influenza viruses are subject to rapid antigenic evolution which translates into frequent updates of the composition of seasonal influenza vaccines. Despite these updates, the effectiveness of influenza vaccines against H3N2-associated disease is suboptimal. Seasonal influenza vaccines primarily induce hemagglutinin-specific antibody responses. However, antibodies directed against influenza neuraminidase (NA) also contribute to protection. Here, we analysed the antigenic diversity of a panel of N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. The antigenic breadth of these NAs was determined based on the NA inhibition (NAI) of a broad panel of ferret and mouse immune sera that were raised by infection and recombinant N2 NA immunisation. This assessment allowed us to distinguish at least four antigenic groups in the N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. Computational analysis further revealed that the amino acid residues in N2 NA that have a major impact on susceptibility to NAI by immune sera are in proximity of the catalytic site. Finally, a machine learning method was developed that allowed to accurately predict the impact of mutations that are present in our N2 NA panel on NAI. These findings have important implications for the renewed interest to develop improved influenza vaccines based on the inclusion of a protective NA antigen formulation.

The antigenic landscape of human influenza N2 neuraminidases from 2009 until 2017

Human H3N2 influenza viruses are subject to rapid antigenic evolution which translates into frequent updates of the composition of seasonal influenza vaccines. Despite these updates, the effectiveness of influenza vaccines against H3N2-associated disease is suboptimal. Seasonal influenza vaccines primarily induce hemagglutinin-specific antibody responses. However, antibodies directed against influenza neuraminidase (NA) also contribute to protection. Here, we analysed the antigenic diversity of a panel of N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. The antigenic breadth of these NAs was determined based on the NA inhibition (NAI) of a broad panel of ferret and mouse immune sera that were raised by infection and recombinant N2 NA immunisation. This assessment allowed us to distinguish at least four antigenic groups in the N2 NAs derived from human H3N2 viruses that circulated between 2009 and 2017. Computational analysis further revealed that the amino acid residues in N2 NA that have a major impact on susceptibility to NAI by immune sera are in proximity of the catalytic site. Finally, a machine learning method was developed that allowed to accurately predict the impact of mutations that are present in our N2 NA panel on NAI. These findings have important implications for the renewed interest to develop improved influenza vaccines based on the inclusion of a protective NA antigen formulation.

Red Blood Cell Alloimmunization in Pregnancy: A Review of the Pathophysiology, Prevalence, and Risk Factors.

This review paper provides an overview of the risk factors and laboratory testing for red blood cell (RBC) alloimmunization in pregnancy. RBC alloimmunization is a significant medical issue that can cause haemolytic disease of the fetus and newborn (HDFN), leading to neonatal morbidity and mortality. Current HDFN prophylaxis targets only Rhesus D (RhD) alloimmunization, with no effective measures to prevent alloimmunization to other RBC antigen groups. Several factors can increase the risk of developing RBC alloimmunization during pregnancy, including fetomaternal haemorrhage, RBC and maternal genetic status, and previous transfusions. Identifying these risk factors is essential to execute the appropriate management strategies to minimize the risk of HDFN. The review also discusses the laboratory methods and overview of pregnancy management. The paper highlights the importance of identifying and managing the risk factors for RBC alloimmunization in pregnancy to minimize the risk of HDFN and improve neonatal outcomes.

Impact of Asian and Black Donor and Recipient Ethnicity on the Outcomes After Deceased Donor Kidney Transplantation in the United Kingdom.

Patients of Asian and black ethnicity face disadvantage on the renal transplant waiting list in the UK, because of lack of human leucocyte antigen and blood group matched donors from an overwhelmingly white deceased donor pool. This study evaluates outcomes of renal allografts from Asian and black donors. The UK Transplant Registry was analysed for adult deceased donor kidney only transplants performed between 2001 and 2015. Asian and black ethnicity patients constituted 12.4% and 6.7% of all deceased donor recipients but only 1.6% and 1.2% of all deceased donors, respectively. Unadjusted survival analysis demonstrated significantly inferior long-term allograft outcomes associated with Asian and black donors, compared to white donors. On Cox-regression analysis, Asian donor and black recipient ethnicities were associated with poorer outcomes than white counterparts, and on ethnicity matching, compared with the white donor-white recipient baseline group and adjusting for other donor and recipient factors, 5-year graft outcomes were significantly poorer for black donor-black recipient, Asian donor-white recipient, and white donor-black recipient combinations in decreasing order of worse unadjusted 5-year graft survival. Increased deceased donation among ethnic minorities could benefit the recipient pool by increasing available organs. However, it may require a refined approach to enhance outcomes.

The effect of hydatid cyst protoscolex somatic antigens on full-thickness skin wound healing in mouse.

Wound healing has evolved in recent years, resulting in diverse therapeutic options. This study evaluated the effects of the somatic antigen of the hydatid cyst protoscolex on wound healing in mice with full-thickness skin wounds. Fifty-four adult mice, weighing 25±5g and approximately 60 days old, were divided into three groups (A, B, and C), each further divided into three subgroups. Subgroups A1, A2, and A3 were assigned negative controls. B1, B2, and B3 received hydatid cyst somatic antigen tests at 10µg/SC, whereas C1, C2, and C3 received somatic antigen tests at 20µg/SC. Under general anesthesia, a wound biopsy puncture of 9.8mm in diameter was performed on the mice's back and spine. In the experimental group, antigen and alum adjuvant were administered subcutaneously around the wound, while the control group received Phosphate-Buffered Saline (PBS). Using digital images, a geometric assessment was conducted on days 0, 1, 3, 6, 9, 12, 15, 18, and 21 post-wounding. The obtained images were analyzed by Image J software and after analyzing the data by SPSS software. A significant difference in terms of epithelization was observed in the antigen treatment group with a dose of 20µg on days 3 and 6 (P<0.05). Furthermore, the 20µg antigen group was significantly higher than the 10µg antigen group in terms of this factor on day 3 (P<0.05). Skin samples were taken from all wounds on days 3, 10 and 21 for microscopic evaluation. Regarding epithelization, on day 10, a significant difference was observed in the treatment group with a concentration of 10µg with the control group and the treatment group with a concentration of 20µg (P<0.05). Based on the results of the present study, it can be concluded that somatic antigens of protoscolex hydatid cyst are dose-dependent and antigens with a dose of 20µg by subcutaneous injection accelerate wound healing and epithelialization.

Mucosal Immunization with Spore-Based Vaccines against Mannheimia haemolytica Enhances Antigen-Specific Immunity.

Mannheimia haemolytica is a bovine respiratory pathogen commonly associated with bacterial bronchopneumonia. Current vaccine strategies have shown variable efficacy in feedlot cattle, and therefore novel vaccines are needed. Bacillus subtilis spores have been investigated as a mucosal vaccine platform, due to their ability to bind and present antigens to the mucosa and act as an adjuvant. The aim of this study was to develop two spore-based mucosal vaccines targeting M. haemolytica and evaluate their immunogenicity in mice. Two antigen constructs composed of cholera toxin B subunit, M. haemolytica leukotoxin, and either the M. haemolytica outer membrane protein PlpE (MhCP1) or GS60 (MhCP2) were synthesized, purified and then bound to spores as vaccines. In two separate mice trials, the spore-bound vaccines (Spore-MhCP1 and Spore-MhCP2) were administered to mice through intranasal and intragastric routes, while free antigens were administered intranasally and intramuscularly. Unbound spores were also evaluated intranasally. Antigen-specific serum IgG and mucosal IgA from bronchoalveolar lavage, feces, and saliva were measured after vaccination. Mice sera from all treatment groups were assessed for their bactericidal activity against M. haemolytica. In both mice experiments, intramuscular immunization induced the strongest serum IgG antibody response. However, the intranasal administration of Spore-MhCP1 and Spore-MhCP2 elicited the greatest secretory IgA-specific response against leukotoxin, PlpE, and GS60 in bronchoalveolar lavage, saliva, and feces (p < 0.05). Compared to the intranasal administration of free antigen, spore-bound antigen groups showed greater bactericidal activity against M. haemolytica (p < 0.05). Since intranasally delivered Spore-MhCP1 and Spore-MhCP2 elicited both systemic and mucosal immune responses in mice, these vaccines may have potential to mitigate lung infection in cattle by restricting M. haemolytica colonization and proliferation in the respiratory tract. The efficacy of these mucosal spore-based vaccines merits further assessment against M. haemolytica in cattle.