Interleukin 5 is a differentiation factor for IgA B cells

摘要

AbstractInterleukin 5 (IL 5) stimulates murine B cells to IgA productionin vitro.The present study examined the B cell target of IL 5 activity, and asked whether IL 5 acts as an isotype switch factor, a growth factor, or a differentiation factor on B cells that produce the IgA isotype. Lipopolysaccharide‐activated surface IgM‐positive, surface IgA‐positive or surface IgA‐negative B cell populations from spleen or Peyer's patches were stimulated with IL 5, after which the expression of cell surface IgA, IgA secretion, and numbers of IgA‐secreting cells were determined. IL 5 increased the IgA response by acting on B cells that are already committed to IgA expression. Thus, with regard to the IgA response, IL 5 acts as a differentiation factor, rather than a growth or IgA isotype swit