B cells defined by immunoglobulin isotypes

Abstract

Summary The ability of B cells to generate antibodies and provide long-lived protective immunity is the cornerstone of vaccination and has contributed to the success of modern medicine. The nine different antibody subclasses produced by humans have effector functions that differ according to antigen type and route of exposure. Expression of the appropriate isotype is critical for effective humoral immunity, and it is becoming clear that subclass specificity is to some extent reflected at the cellular level. Understanding the mechanisms that govern the induction, expansion, and maintenance of B cells expressing different antibody subclasses informs the strategic manipulation of responses to benefit human health. This article provides an overview of the mechanisms by which the different human antibody subclasses regulate immunity, presents an update on how antibody subclass expression is regulated at the cellular level and highlights key areas for future research.

Immunomodulatory Aspects of Therapeutic Plasma Exchange in Neurological Disorders—A Pilot Study

“…Moreover, levels of IgG1-3 remained depleted throughout the whole study period and did not reach baseline values at follow-up2. Whether the more prominent recovery of IgM and IgA, which are both involved in early host defense [ 13 ], contributes to the low infection rates associated with TPE remains to be further explored. However, our data clearly show that despite the transient washout, pathogen-specific antibodies fully recover to baseline values within a few months from TPE.…”

“…The kinetics of circulating antibody levels are regulated by the distribution and production rate of immunoglobulins as well as by their half-lives [ 14 ]. Antibodies are synthesized and secreted by terminally differentiated B cells, mostly long-lived plasma cells settled in niches within the bone marrow and secondary lymphoid tissues [ 13 ]. As a result, plasma cells and their capacity to produce pathogenic autoantibodies likely remain unaffected by TPE, indicating a short-lasting duration of the clinical TPE benefits.…”

B-Cell Receptor Signaling and Beyond: The Role of Igα (CD79a)/Igβ (CD79b) in Normal and Malignant B Cells

“…Following antigen-induced SYK (spleen tyrosine kinase)-mediated phosphorylation, the ITT facilitates docking of adaptor protein Grb2 (growth factor receptor-bound protein 2). Grb2 in turn recruits BTK, which leads to the amplification of Ca 2+ mobilization and resulting amplification of BCR signaling [ 66 , 67 , 68 , 69 ]. However, the CD79a/CD79b heterodimer is critically important for a general BCR signal transduction [ 70 , 71 ].…”