title: Increased competition for antigen during priming negatively impacts the generation of memory CD4 T cells.
abstract: The factors involved in the differentiation of memory CD4 T cells from naïve precursors are poorly understood. We developed a system to examine the effect of increased competition for antigen by CD4 T cells on the generation of memory in response to infection with a recombinant vesicular stomatitis virus. Competition was initially regulated by increasing the precursor frequency of adoptively transferred naïve T cell antigen receptor transgenic CD4 T cells. Despite robust proliferation at high precursor frequencies, memory CD4 T cells did not develop, whereas decreasing the input number of naïve CD4 T cells promoted memory development after infection. The lack of memory development was linked to reduced blastogenesis and poor effector cell induction, but not to initial recruitment or proliferation of antigen-specific CD4 T cells. To prove that availability of antigen alone could regulate memory CD4 T cell development, we used treatment with an mAb specific for the epitope recognized by the transferred CD4 T cells. At high doses, this mAb effectively inhibited the antigen-specific CD4 T cell response. However, at a very low dose of mAb, primary CD4 T cell expansion was unaffected, although memory development was dramatically reduced. Moreover, the induction of effector function was concomitantly inhibited. Thus, competition for antigen during CD4 T cell priming is a major contributing factor to the development of the memory CD4 T cell pool.
authors.affiliation: Department of Immunology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-1319, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Blair
authors.forename: Leo
authors.initials: L
authors.lastname: Lefrançois
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D000941:Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002455:Cell Division; D005434:Flow Cytometry; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic