Generation and characterization of a monoclonal antibody that inhibits stromal cell-dependent B lymphopoiesis.
We generated a mAb, R4, against a stromal cell line, ST2, which is one of several stromal cell lines that can support in vitro B lymphopoiesis. Flow cytometry studies using R4 revealed that R4 reacted with several stromal, fibroblast, and some B cell lines, but not with freshly isolated bone marrow cells, splenocytes, thymocytes, or T cell lines. R4 could immunoprecipitate a M(r) = 24-kDa protein (p24) and a M(r) = 55-kDa protein (p55) from a stromal cell line and a B cell line, respectively. R4 inhibited the development of B cell progenitors from bone marrow cells in cultures supported by stromal cell lines, ST2, or op/op fibroblast line, but did not inhibit myelopoiesis supported by ST2. R4 also inhibited the growth of a stromal cell-dependent pre-B cell line, DW8, but not of two stromal cell-independent B cell lines, 70Z/3 and M12, despite the fact that R4 reacted all three of these lines. Because R4 inhibited B lymphopoiesis in the transwell culture where stromal cells are not allowed to contact pre-B cells, R4 Ag may not directly affect cellular contact. In vivo treatment of pregnant mice with R4 caused a reduction in the number of B cell progenitors in the bone marrows of some of the newborn offspring.
Nagasawa
T
T
Division of Immunology, Osaka University, Japan.
Kaisho
T
T
Kishimoto
T
T
Kikutani
H
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology*; D001854:Bone Marrow Cells; D002450:Cell Communication; D002460:Cell Line; D002478:Cells, Cultured; D006410:Hematopoiesis; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017207:Rats, Sprague-Dawley; D017154:Stromal Cells / Q000502:physiology
D000911:Antibodies, Monoclonal