Restricted tissue distribution of Mlsa determinants. Stimulation of Mlsa-reactive T cells by B cells but not by dendritic cells or macrophages.
Evidence was sought on the tissue distribution of Mlsa determinants, a class of cell-associated non-H-2 alloantigens that is highly immunogenic for unprimed T cells. Whereas normal CD4+ T cells and an Mlsa-reactive T hybridoma gave strong responses to Mlsa-positive stimulator populations containing Ig+ B cells, anti-Mlsa responses to B-depleted stimulators were almost undetectable. The B-depleted stimulators tested included Thy-1- spleen cells from mu-suppressed mice (mice treated with anti-mu antibody from birth) and J11d- preparations of spleen dendritic cells (DC) and peritoneal macrophages (M phi) from normal mice. Each of these populations was strongly immunogenic for allo-H-2-reactive T cells. The failure to detect Mlsa determinants on Ig- APC, i.e., M phi and DC, suggests that Mlsa determinants are not typical H-2-associated peptides. The data are more compatible with a model in which Mlsa determinants represent (or form part of) an integral cell membrane molecule expressed largely, and perhaps exclusively, on B cells. T cells might recognize these molecules only in native form, "processed" Mlsa determinants being nonimmunogenic. Consistent with this possibility, no evidence was found that Mlsa-negative B cells could absorb Mlsa determinants from Mlsa-positive B cells in a chimeric environment.
Webb
S R
SR
Research Institute of Scripps Clinic, La Jolla, California 92037.
Okamoto
A
A
Ron
Y
Y
Sprent
J
J
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D000954:Antigens, Surface / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D006825:Hybridomas; D066298:In Vitro Techniques; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D016747:Minor Lymphocyte Stimulatory Antigens; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014018:Tissue Distribution
D000954:Antigens, Surface; D016747:Minor Lymphocyte Stimulatory Antigens