PubMed · 4797660
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
M A Chaves. 1973. [Transfer factor].. https://pubmed.ncbi.nlm.nih.gov/4797660/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Polyreactive antibodies are naturally occurring antibodies, primarily of the IgM isotype, that are capable of reacting with a wide variety of different self and non-self antigens. Previously, we reported that a B cell capable of making polyreactive antibody has Ig receptors on its surface that can bind different antigens. The present investigation was initiated to characterize these polyreactive antigen-binding B cells further. A panel of fluorescein isothiocyanate-labeled antigens (insulin, IgG Fc fragment or beta-galactosidase) served as probes to select polyreactive antigen-binding B cells by cell sorting. Our experiment revealed that these polyreactive antigen-binding B cells were mainly of the IgD isotype. They expressed high levels of CD40 and major histocompatibility complex class II molecules, but little or no B7-1, B7-2, or Fas. In contrast to the binding of antigens to monoreactive receptors (usually high affinity), the binding of antigens to polyreactive receptors (usually moderate or low affinity) did not up-regulate the expression of B7-1 or B7-2. Antigens that bound to polyreactive receptors, however, were internalized and degraded, although not as efficiently as antigens that bound to monoreactive receptors. Despite the ability of these B7- cells to process antigens, they were not able to activate T cells in a mixed leukocyte reaction. It is concluded that polyreactive antigen-binding B cells have properties that are consistent with the ability to induce immunological tolerance.
Based on immunoassay principles, methods have been developed for the analysis of secreted products at the cellular level. This approach offers substantial methodological advantages compared to traditional immunoassays. In a number of applications cell-based methods have proved able to overcome many of the problems inherent to immunoassays of biological fluids. This review focuses on applications of ELISPOT in natural infections and vaccinations of human individuals. The studies reviewed here have contributed to our understanding of the B-cell responses in infections and the independence of mucosal and systemic immune responses. Whilst diagnostic applications are rare, enzyme immunospot assays have been extensively used in testing the immunogenicity of vaccines. In particular, B-cell responses to mucosal vaccines are better covered with this cellular assay.
We have established anti-colon antibodies producing B cell clones from the patient with ulcerative colitis, and analyzed the immunoglobulin heavy chain variable region (VH) gene segments of these clones using RT-PCR with VH family specific primers. VH3 family was used by all ten clones from ulcerative colitis that produced anti-colon antibodies, while various VH gene families were used by eight clones from normal controls. By nucleotide sequence analysis, two LPL clones were thought to be derived from a germ line gene segment, VH26. However, other three PBL clones were derived from 22-2B, 9-1 and 1.9-III, respectively. These results suggest the heterogeneity of the colonic antigens that autoantibodies in ulcerative colitis recognize.