Variable-region-identical mouse immunoglobulin G1 (IgG1), IgG2b, and IgG2a monoclonal antibodies to the capsular polysaccharide of Cryptococcus neoformans prolong the lives of mice infected with this fungus, while IgG3 is either not protective or enhances infection. CD4+ T cells are required for IgG1-mediated protection, and CD8+ T cells are required for IgG3-mediated enhancement. Gamma interfe...

Here, we report a genome-wide survey of immunoglobulin light chain (IGL) genes of torafugu (Takifugu rubripes) revealing multi-clusters spanning three separate chromosomes (v5 assembly) and 45 scaffolds (v4 assembly). Conventional sequence similarity searches and motif scanning approaches based on recombination signal sequence (RSS) motifs were used. We found that three IGL isotypes (L1, L2, an...

Studies using both human and murine lymphoid cells have established that the predominant immunoglobulin isotypes on the cell surface of B lymphocytes are IgM and IgD (1-6). Moreover, the majority of B cells express both isotypes simultaneously (2, 3, 79). A minority of B cells bear surface IgG (10, 11). Recently, several investigators have studied the immune function of primed (memory) B cells ...

This study shows markedly different isotype distributions of antibodies to asexual blood stages of Plasmodium falciparum and to merozoite surface protein 1 in clinically immune Senegalese adults depending on the study site. The relationships between immunoglobulin M (IgM) and IgG and between IgG3 and IgG1 antibodies differed in settings where transmission is perennial compared to settings where...

For nearly three decades, R loops have been closely linked with class switch recombination (CSR), the process that generates antibody isotypes and that occurs via a complex cascade initiated by transcription-coupled mutagenesis in switch recombination sequences. R loops form during transcription of switch recombination sequences in vitro and in vivo, and there is solid evidence that R loops are...

Viruses such as lactate dehydrogenase-elevating virus and adenovirus induce in vivo a polyclonal activation of murine B lymphocytes, followed by a marked increase in the production of immunoglobulin G2a (IgG2a). The role of T lymphocytes in this phenomenon was studied by injection of an anti-CD4 monoclonal antibody able to inhibit the T-helper function. This treatment profoundly depressed the p...

Pemphigoid, a group of autoimmune bullous diseases including pemphigoid (BP) and epidermolysis bullosa acquisita, is caused by autoantibodies against the basement membrane zone (BMZ). BP most common disease in elderly, suggesting that aging involved disruption immune tolerance to BMZ. However, details process are still not fully understood. To investigate effects on breakdown BMZ, we analyzed p...

This investigation describes the detection of a component in Escherichia coli capable of binding a large proportion of human antibody variable domains including otherwise highly monospecific antibodies induced by an in vivo antibody response. This interaction is of low affinity, but cross-linking of IgG molecules by, e.g. anti-immunoglobulin preparations, provides a sufficient degree of multiva...

LPS was used to induce switching of B cells to IgG3 and, in the presence of TGF-beta, to IgG2b and IgA. Switching to all three isotypes increased with division number according to a consistent relationship that was independent of time in culture. The mode of activation altered the relationship with division, as CD40 ligand increased switching to IgA and decreased switching to IgG2b and IgG3 whe...

Ig class switch recombination (CSR) requires expression of activation-induced deaminase (AID) and production of germline transcripts to target S regions for recombination. However, the mechanism of CSR remains unclear. Here we show that an extrachromosomal S plasmid assay is AID dependent and that a single consensus repeat is both necessary and sufficient for isotype-specific CSR. Transfected s...