title: Memory phenotype of CD8+ T cells in MHC class Ia-deficient mice.
abstract: B6.K(b-)D(b-) mice are devoid of class Ia but express normal levels of class Ib molecules. They have low levels of CD8 T cells in both the thymus as well as peripheral T cell compartments. Although the percentage of splenic CD8 alpha alpha T cells is increased in these animals, approximately 90% of CD8 T cells are CD8 alpha beta. In contrast to B6 animals, most of the CD8 T cells from these mice have a memory phenotype (CD44(high)CD122(high) CD62L(low)) including both CD8 alpha beta and CD8 alpha alpha subsets. In the thymus of B6.K(b-)D(b-) animals, there is a decrease in the percentage of SP CD8 T cells, although most are CD44(low), similar to that seen in B6 mice. The spleens from day 1-old B6 and B6.K(b-)D(b-) mice have a relatively high proportion of CD44(high)CD62L(low) CD8 T cells. However, by day 28 most CD8 T cells in B6 mice have a naive phenotype while in B6.K(b-)D(b-) mice the memory phenotype remains. Unlike CD44(high) cells that are found in B6 animals, most CD44(high) cells from B6.K(b-)D(b-) mice do not secrete IFN-gamma rapidly upon activation. The paucity of CD8 T cells in B6.K(b-)D(b-) mice might be due in part to their inability to undergo homeostatic expansion. Consistent with this, we found that CD8 T cells from these animals expand poorly in X-irradiated syngeneic hosts compared with B6 CD8 T cells that respond to class Ia Ags. We examined homeostatic expansion of B6 CD8 T cells in single as well as double class Ia knockout mice and were able to estimate the fraction of cells reactive against class Ia vs class Ib molecules.
authors.affiliation: Center for Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Kurepa
authors.forename: Jie
authors.initials: J
authors.lastname: Su
authors.forename: James
authors.initials: J
authors.lastname: Forman
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D005802:Genes, MHC Class II / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis / Q000235:genetics*; D006706:Homeostasis / Q000235:genetics / Q000276:immunology; D018960:Hyaluronan Receptors / Q000096:biosynthesis; D007153:Immunologic Deficiency Syndromes / Q000235:genetics / Q000276:immunology / Q000473:pathology; D007156:Immunologic Memory / Q000235:genetics*; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000378:metabolism; D019041:L-Selectin / Q000096:biosynthesis; D018655:Lymphocyte Count; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D064532:Histocompatibility Antigen H-2D; D000949:Histocompatibility Antigens Class II; D018960:Hyaluronan Receptors; D019041:L-Selectin; D007371:Interferon-gamma