Interleukin 5 and interleukin 4 produced by Peyer's patch T cells selectively enhance immunoglobulin A expression.
Considerable evidence suggests that the high frequency of B cells committed to the IgA isotype in Peyer's patches is regulated by T lymphocytes. To understand more accurately the mechanism of this immunoregulation, an autoreactive T cell line from Peyer's patches was generated by culturing L3T4+ Peyer's patches T cells with syngeneic B cell blasts. The resulting T cell line, designated PT-1, and a clone derived from this line, PT-1.14, stimulated immunoglobulin secretion in spleen B cells with a preferential enhancement of IgA and IgG1 isotypes. Supernatant derived from concanavalin A-stimulated PT-1 or PT-1.14 cells could also enhance IgA secretion if spleen B cells were preactivated with lipopolysaccharide. Peyer's patches T cell supernatant did not contain IgA-specific binding factors. PT-1 supernatant scored positive in lymphokine assays for interleukin (IL)-2, IL-4 (B cell stimulatory factor 1), IL-5 (B cell growth factor II), and interferon-gamma, whereas PT-1.14 supernatant was positive for IL-4 and IL-5 and negative for IL-2 and interferon-gamma. Only IL-5 enhanced IgA secretion in lipopolysaccharide-activated B cells and this response was increased two- to three-fold by IL-4. These results suggest that the type 2 T helper subset which produces both IL-5 and IL-4 plays a primary role in regulating IgA expression.
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis; D015847:Interleukin-4; D015848:Interleukin-5; D007378:Interleukins / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D010581:Peyer's Patches / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D015848:Interleukin-5; D007378:Interleukins; D008070:Lipopolysaccharides; D015847:Interleukin-4