Monoclonal antibodies that block adhesion of B cell progenitors to bone marrow stroma in vitro prevent B cell differentiation in vivo.
B cell differentiation requires adhesion of B cell progenitors to bone marrow (BM) or fetal liver stroma. We show that B lymphoid cells can adhere to the BM stroma cell line CS 1.3, in vitro. Two monoclonal antibodies, SAB-1 and SAB-2, inhibited the adhesion of a B220+ progenitor B cell line but did not interfere with the binding of cytoplasmic mu chain-positive pre-B cells or mature B cells to the BM stromal cell line. Injection of both SAB-1 and SAB-2 antibodies into pregnant mice reduced by 90% the number of B220+n B lineage cells in the livers of their embryos. Livers from such embryos also were virtually devoid of cells able to give rise to B cell colonies in soft agar cultures (CFU-preB). Either antibody separately had no effect. Flow cytometry analysis show that SAB-1 is present on CS 1.3 stroma cells and on a pre-B cell line while SAB-2 is present on pro-B and pre-B cell lines, but not on CS 1.3 stromal cells. SAB-1 and SAB-2 react with different molecules and neither antibody seems to recognize CD44, and adhesion molecule that may also participate in B cell differentiation. Proteinase K and trypsin can digest both SAB-1 and SAB-2 antigens from viable cells suggesting that both are cell surface proteins. We propose that antibodies SAB-1 and SAB-2 probably recognize novel cell-cell adhesion molecules, and that these molecules are involved in the interactions between B cell progenitors and stroma cells.
Imhof
B A
BA
Basel Institute for Immunology, Switzerland.
Schlienger
C
C
Handloser
K
K
Hesse
B
B
Slanicka
M
M
Gisler
R
R
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D000954:Antigens, Surface / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000166:cytology*; D002448:Cell Adhesion / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D003114:Colony-Forming Units Assay; D019286:Endopeptidase K; D005333:Fetus / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000473:pathology; D051379:Mice; D009439:Neuraminidase / Q000494:pharmacology; D010920:Placenta / Q000276:immunology; D016201:Receptors, Lymphocyte Homing / Q000276:immunology; D012697:Serine Endopeptidases / Q000494:pharmacology; D014018:Tissue Distribution; D014357:Trypsin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D015815:Cell Adhesion Molecules; D016169:Lymphocyte Function-Associated Antigen-1; D016201:Receptors, Lymphocyte Homing; D009439:Neuraminidase; D006821:Hyaluronoglucosaminidase; D012697:Serine Endopeptidases; D014357:Trypsin; D019286:Endopeptidase K