Inside the thymus, Mls antigen is exclusively presented by B lymphocytes.
The ability to stimulate an Mls-1 mixed lymphocyte reaction (MLR) is predominantly expressed by low density B lymphocytes in the spleen and peritoneal cavity of normal adult mice, and is absent in splenic B cells 1 month after lethal irradiation and reconstitution from autologous bone marrow. Coreconstitution of these mice with normal syngeneic peritoneal cells restores the stimulatory potential of splenic B cells, but sorted CD5+ or CD5- IgM+ lymphocytes from peritoneum are equally good stimulators, suggesting that functional Mls-1 expression may require long life spans and selection. Bone-marrow-reconstituted DBA/2 mice that fail to express Mls-1 antigens in the periphery nevertheless maintain T-cell receptor V beta 6 and 8.1 deletions among the newly formed T cells. These findings led us to directly investigate the Mls stimulatory ability of purified antigen-presenting cell populations inside the thymus. We report here that thymic B lymphocytes seem to represent the only intrathymic cell population able to stimulate Mls-1 MLR.
Faro
J
J
Unité d'Immunobiologie, Institut Pasteur, Paris.
Marcos
M A
MA
Andreu
J L
JL
Martinez-A
C
C
Coutinho
A
A
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology / Q000528:radiation effects; D018956:CD5 Antigens; D005434:Flow Cytometry; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D016747:Minor Lymphocyte Stimulatory Antigens; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
D000943:Antigens, Differentiation; D000954:Antigens, Surface; D018956:CD5 Antigens; D008562:Membrane Glycoproteins; D016747:Minor Lymphocyte Stimulatory Antigens; D011948:Receptors, Antigen, T-Cell