Complement component C1q is an immunological rheostat that regulates Fc:Fc $$\gamma$$ R interactions
In this report, we use recombinant human Fc multimers as stable IC mimics to show that C1q engagement of ICs directly and transiently inhibits their interactions with Fc\(\gamma\)RIII (CD16) on human natural killer (NK) cells. This inhibition occurs by C1q engagement alone as well as in concert with other serum factors. Furthermore, the inhibition of Fc\(\gamma\)RIII engagement mediated by avid binding of C1q to ICs is directly associated with IC size and dependent on the concentrations of both C1q and Fc multimers present. Functionally, C1q-mediated Fc blockade limits the ability of NK cells to induce the upregulation of ...
Source: Immunogenetics - June 15, 2023 Category: Genetics & Stem Cells Source Type: research
Immunological assessment of a patient with Omenn syndrome resulting from compound heterozygous mutations in the RAG1 gene
In this study, we presented a case study of a 41-day-old female infant who exhibited symptoms of generalized erythroderma, lymphadenopathy, hepatosplenomegaly, and recurrent infections including suppurative meningitis and septicemia. The patient showed a T+B−NK+ immunophenotype. We observed an impaired thymic output, as indicated by reduced levels of naive T cells and sjTRECs, coupled with a restricted TCR repertoire. Additionally, T-cell CFSE proliferation was impaired, indicating a suboptimal T-cell response. Notably, our data further revealed that T cells were in an activated state. Genetic analysis revealed a previou...
Source: Immunogenetics - June 3, 2023 Category: Genetics & Stem Cells Source Type: research
Immunogenetics special issue 2023: Immunogenetics of infectious disease
(Source: Immunogenetics)
Source: Immunogenetics - May 24, 2023 Category: Genetics & Stem Cells Source Type: research
Evaluation of miRNA-16 –2-3P, miRNA-618 levels and their diagnostic and prognostic value in the regulation of immune response during SARS Cov-2 infection
AbstractFollowing the announcement of the pandemic of COVID-19 in December 2019, several studies focused on how to early predict the severity of the disease in symptomatic and asymptomatic patients. Many cytokines including interleukin-6, interleukin-8, and tumor necrotic factors have been concluded as strong indicators for COVID-19 infection. Additionally, miRNAs have been associated with dysregulation in the immune system. The aim of this study are the following: (1) to estimate the level of miRNA-16 –2-3P, miRNA-618, IL-8, IL-1β as predictors for SARS-CoV-2 complications in PCR negative and positive patients; (2) to ...
Source: Immunogenetics - May 24, 2023 Category: Genetics & Stem Cells Source Type: research
Immunogenetics special issue 2023: Immunogenetics of infectious disease
(Source: Immunogenetics)
Source: Immunogenetics - May 23, 2023 Category: Genetics & Stem Cells Source Type: research
Germline-enforced enrichment for charged amino acids in TCR beta chain (TCR β) complementarity determining region 3 (CDR-B3) alters T cell development, repertoire content, and antigen recognition
AbstractT cell receptor beta chain (TCR β) diversity (Dβ) gene segments are highly conserved across evolution, with trout Dβ1 sequence identical to human and mouse Dβ1. A key conserved feature is enrichment for glycine in all three Dβ reading frames (RFs). Previously, we found that replacement of mouse Dβ1 with a typical immunoglobu lin DH sequence, which unlike D β is enriched for tyrosine, leads to an increase in the use of tyrosine in TCRβ complementarity determining region 3 (CDR-B3) after thymic selection, altering T cell numbers, CDR-B3 diversity, and T cell function. To test whether the incorporation of char...
Source: Immunogenetics - April 29, 2023 Category: Genetics & Stem Cells Source Type: research
Evolution of immunogenetic components encoding ultralong CDR H3
We examined genomes of twelve species of Bovidae to determine when ultralong-encoding IGHV and IGHD gene segments evolved. We located the 8-bp duplication encoding the unique TTVHQ motif in ultralong IGHV segments in six Bovid species (cattle, zebu, wild yak, domestic yak, American bison, and domestic gayal), but we did not find evidence of the duplication in species beyond theBos andBison genera. Additionally, we analyzed mRNA from bison spleen and identified a rich repertoire of expressed ultralong CDR H3 antibody mRNA, suggesting that bison use ultralong IGHV transcripts in their host defense. We found ultralong-encodin...
Source: Immunogenetics - April 21, 2023 Category: Genetics & Stem Cells Source Type: research
Impact of high human genetic diversity in Africa on immunogenicity and efficacy of RTS,S/AS01 vaccine
AbstractIn modern medicine, vaccination is one of the most effective public health strategies to prevent infectious diseases. Indisputably, vaccines have saved millions of lives by reducing the burden of many serious infections such as polio, tuberculosis, measles, pneumonia, and tetanus. Despite the recent recommendation by the World Health Organization (WHO) to roll out RTS,S/AS01, this malaria vaccine still faces major challenges of variability in its efficacy partly due to high genetic variation in humans and malaria parasites. Immune responses to malaria vary between individuals and populations. Human genetic variatio...
Source: Immunogenetics - April 21, 2023 Category: Genetics & Stem Cells Source Type: research
Evolution of immunogenetic components encoding ultralong CDR H3
We examined genomes of twelve species of Bovidae to determine when ultralong-encoding IGHV and IGHD gene segments evolved. We located the 8-bp duplication encoding the unique TTVHQ motif in ultralong IGHV segments in six Bovid species (cattle, zebu, wild yak, domestic yak, American bison, and domestic gayal), but we did not find evidence of the duplication in species beyond theBos andBison genera. Additionally, we analyzed mRNA from bison spleen and identified a rich repertoire of expressed ultralong CDR H3 antibody mRNA, suggesting that bison use ultralong IGHV transcripts in their host defense. We found ultralong-encodin...
Source: Immunogenetics - April 21, 2023 Category: Genetics & Stem Cells Source Type: research
Impact of high human genetic diversity in Africa on immunogenicity and efficacy of RTS,S/AS01 vaccine
AbstractIn modern medicine, vaccination is one of the most effective public health strategies to prevent infectious diseases. Indisputably, vaccines have saved millions of lives by reducing the burden of many serious infections such as polio, tuberculosis, measles, pneumonia, and tetanus. Despite the recent recommendation by the World Health Organization (WHO) to roll out RTS,S/AS01, this malaria vaccine still faces major challenges of variability in its efficacy partly due to high genetic variation in humans and malaria parasites. Immune responses to malaria vary between individuals and populations. Human genetic variatio...
Source: Immunogenetics - April 21, 2023 Category: Genetics & Stem Cells Source Type: research
Characterization and genetic diversity of MHC class II DRB genes in the Arabian camel (Camelus dromedarius)
This study investigated the MHC DRB genes in the Arabian camel (Camelus dromedarius). The results revealed the presence of — at least — two transcribed DRB-like genes in chromosome 20, designatedMhcCadr-DRB1 andMhcCadr-DRB2. These genes are 155 Kb apart, have similar gene structure, and are transcribed in opposite directions. Compared toDRB1, theDRB2 locus contains a deletion of 12 nucleotides in the second exon (270 bp), exhibits lower transcript abundance, and is expressed as two splice variants differing by exon 2 skipping. This gene seems to be of minor functional relevance in the dromedary camel. Conversely, t...
Source: Immunogenetics - April 4, 2023 Category: Genetics & Stem Cells Source Type: research
