Schistosoma mansoni eggs induce antigen-responsive CD44-hi T helper 2 cells and IL-4-secreting CD44-lo cells. Potential for T helper 2 subset differentiation is evident at the precursor level.
Schistosoma mansoni eggs are potent inducers of biased Th2-like immune responses. Using a model system where mice are immunized with isolated schistosome eggs, we demonstrate that CD44 expression, up-regulation of which has been linked to Th cell development, is increased on Th2 cells. We also investigate the functional properties of CD44-lo Th cells recovered from the overtly Th2 environment constituted by lymph nodes draining sites of egg deposition. Production of high levels of IL-4, IL-5, and IL-10 by Th cells responding to egg Ag is shown to be the property of a subpopulation expressing CD44-hi. This population of Th cells cosegregates with a blasting subpopulation expressing more IL-4R (but similar amounts of IL-2R) than Th cells from normal mice. These results indicate that mature Th2 cells responding to schistosome eggs are CD44-hi and suggest that they use IL-4 as a growth factor. In contrast, CD44-lo cells sorted from lymph node populations responding to eggs are able to produce small amounts of IL-4 and IL-2, but no IL-5 or IL-10. This is surprising, because low expression of CD44 is considered a characteristic of Th cell naivite and concomitant ability to produce only IL-2. Thus, in lymph nodes responding to schistosome eggs, potential for Th2 subset differentiation is evident within the CD44-lo precursor Th subpopulation.
Vella
A T
AT
Department of Microbiology, Immunology and Parasitology, Cornell University, Ithaca NY 14853.
Hulsebosch
M D
MD
Pearce
E J
EJ
D000818:Animals; D002454:Cell Differentiation; D016753:Interleukin-10 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis*; D015848:Interleukin-5 / Q000096:biosynthesis; D008212:Lymphocyte Depletion; D051379:Mice; D010063:Ovum / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000032:analysis; D019948:Receptors, Interleukin-4; D016201:Receptors, Lymphocyte Homing / Q000032:analysis*; D011975:Receptors, Mitogen / Q000032:analysis; D012550:Schistosoma mansoni / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D015854:Up-Regulation
D015848:Interleukin-5; D015375:Receptors, Interleukin-2; D019948:Receptors, Interleukin-4; D016201:Receptors, Lymphocyte Homing; D011975:Receptors, Mitogen; D016753:Interleukin-10; D015847:Interleukin-4