An embryonic source of Ly1 but not conventional B cells.
Ly1+ B cells differ from conventional B cells with respect to their anatomical localization, cell surface marker expression, and antibody repertoire suggesting that they may constitute a functionally distinct subset of B cells. To determine whether Ly1+ B cells also have a developmentally distinct site of origin we grafted various fetal primordia into adult severe combined immunodeficient (scid) mice and analyzed their potential to give rise to T and B cells. We demonstrated that fetal omentum, but not spleen or thymus grafts, reconstituted exclusively Ly1 B cells (including the Ly1 sister population) as well as a population of IgM and IgA producing plasma cells in the spleen and gut, respectively. Although thymus grafts regularly reconstituted T cells, thymus plus fetal omentum cografts gave rise to a population of Ly1+ B cells as well as T cells which were also derived from omentum. However, in neither omentum nor omentum plus thymus cografts were conventional B cells detected. These results provide the first evidence that Ly1 B cells but not conventional B cells are generated from the fetal omentum.
Department of Microbiology, University of Alabama, Birmingham 35294.
N
N
Solvason
A
A
Lehuen
J F
JF
Kearney
D000818:Animals; D000950:Antigens, Ly; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000097:blood; D007153:Immunologic Deficiency Syndromes / Q000276:immunology / Q000473:pathology / Q000601:surgery; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009852:Omentum / Q000033:anatomy & histology; D010950:Plasma Cells / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
D000950:Antigens, Ly; D007132:Immunoglobulin Isotypes