TCR-MHC class II interaction is required for peripheral expansion of CD4 cells in a T cell-deficient host.
It is well established that T cell-deficient nude and SCID mice can be reconstituted by i.v. injection of small numbers of purified peripheral CD4+ T cells; however, the requirements for expansion of the transferred T cells in such systems are not clear. We show here that blood and lymphoid organs of MHC class II-deficient mice (which selectively lack mature CD4+ T cells) cannot be reconstituted by transfer of purified splenic CD4+ T cells, whereas TCRalpha-deficient mice (which lack both CD4+ and CD8+ mature T cells) are readily reconstituted. The failure of CD4+ T cell reconstitution in MHC class II-deficient mice was not due to the presence of CD8+ T cells, since similar results were obtained in TCRalpha-MHC class II double-deficient mice. Consistent with most previous studies CD4+ T cells in reconstituted TCRalpha-deficient mice had a diverse TCR Vbeta repertoire and were predominantly of an activated/memory (CD44high) phenotype. Collectively our data demonstrate that the expansion of peripheral CD4+ T cells in a T cell-deficient host is dependent upon interactions of the TCR with MHC class II.
Beutner
U
U
Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland.
MacDonald
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HR
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D000949:Histocompatibility Antigens Class II / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008819:Mice, Nude; D016513:Mice, SCID; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000502:physiology*
D000949:Histocompatibility Antigens Class II; D016693:Receptors, Antigen, T-Cell, alpha-beta