Although IgG2a is the most potent Ab isotype in the host response to viral and bacterial infections, the regulation of class switch recombination to IgG2a in vivo is not yet well understood. Recognition of pathogen-associated molecular patterns by dendritic cells expressing TLRs, like TLR7, recognizing ssRNA, or TLR9, recognizing DNA rich in nonmethylated CG motifs (CpG), favors induction of Th...

After infection with bacillus Calmette-Guérin, peritoneal macrophages (Mø) display enhanced expression of FcR for both monomeric and complexed IgG2a, but not IgG2b. Isotype specificity of FcR can be reversed on nonactivated Mø by immune lymphokines, and IgG2a immune complexes are more effective triggers of the respiratory burst in activated Mø. Selective enhancement of IgG2a FcR by Mø activatio...

We report here that immunization of human PBMC reconstituted SCID mice (hu-PBL-SCID mice) with in vitro cultured autologous dendritic cells (DC) pulsed with prostate specific antigen (PSA) complexed to a PSA-specific mouse IgG2a (PSA-IgG2a) consistently and reproducibly stimulates PSA-specific human IgG production. On day 0, female PBMC were used to reconstitute SCID mice and to generate DC in ...

There are >2 million new cases of leishmaniasis annually, and no effective vaccine has been developed to prevent infection. In murine infection, Leishmania mexicana, which lives intracellularly in host macrophages, has developed pathways to hijack host IgG to induce a suppressive IL-10 response through FcγRs, the cell-surface receptors for IgG. To guide vaccine development away from detrimental...

Using the fluorescence activated cell sorter to select rare IgG2a- and IgG2b-producing variants, we developed switch variant families of hybridomas from IgG1-producing hybridomas, ME1 and MA2.1. The IgG2a and IgG2b antibodies produced by such switch variants have the same binding activities for HLA as the IgG1 antibodies produced by the parent hybridomas. Using these antibodies, we directly com...

background: the ability of polyclonal antibodies to react with many epitopes of an antigen makes them valuable reagents in research and diagnosis. the aim of this study was purification of mouse igg2a and production of polyclonal antibody against purified mouse igg2a subclass. materials and methods: mouse igg2a was purified by proa affinity. verification method of the purified antibody was sds-...

A stable variant of a clone of the P388D1 macrophage line was isolated using four cycles of treatment with mouse IgG2a-rabbit anti-kappa complexes and rabbit complement. The variant had the same Ka and about the same number of sites per cell for IgG2a as the parent line. However, the variant had 10% as many binding sites for rabbit IgG in soluble antigen-antibody complexes, and the affinity of ...

BALB/c mice immunized with human cartilage proteoglycan (PG) develop arthritis accompanied by the production of autoantibodies to mouse cartilage PG. To determine whether the autoantibody isotype contributes to the onset and severity of arthritis, PG-specific serum IgG1 (Th2, IL-4-cytokine-supporting) and IgG2a (Th1, IFN-gamma-controlling) concentrations were monitored during immunization with ...

The factors that determine whether immune complexes (IC) are cleared safely from the circulation or are deposited in vulnerable tissues such as glomeruli are not well defined. To better understand how IC are handled, the present study examined the fate in vivo of three model IC preparations with different immunochemical characteristics. Radiolabeled IC were constructed with murine IgG1, IgG2a, ...

In mice, the IgG subclass induced after Ag encounter can reflect the nature of the Ag. Th2 Ags such as alum-precipitated proteins and helminths induce IgG1, whereas Th1 Ags, such as Salmonella Typhimurium, predominantly induce IgG2a. The contribution of different IgG isotypes to protection against bacteria such as S. Typhimurium is unclear, although as IgG2a is induced by natural infection, it ...