CD44-stimulated dendrite formation ('spreading') in activated B cells.
A rat monoclonal antibody (mAb) (NIM-R8), insolubilized by binding to plastic plates, induced a rapid and extensive formation of dendrite processes ('spreading') in B lymphocytes activated by anti-IgM and interleukin-4 (IL-4) or anti-CD38 and IL-4. In contrast, resting B cells were unable to spread similarly on the NIM-R8-coated plates. The NIM-R8 antibody recognized a 90,000 MW surface glycoprotein (gp90) present on both B and T lymphocytes. The expression of this molecule was greatly increased after polyclonal (lipopolysaccharide, anti-IgM plus IL-4 or concanavalin A) activation. The NIM-R8 mAb with or without IL-2 or IL-4 was unable to induce proliferation of splenic lymphocytes. Following the demonstration that the NIM-R8 mAb recognizes the murine equivalent of human CD44, the induction of spreading of activated B lymphocytes was studied using a panel of mAb recognizing different epitopes of murine CD44. All of these different mAb induced similar spreading of activated B cells. The ligand-inducible spreading of activated B lymphocytes may be an important mechanism for providing an increased cell-surface area for cell-cell or cell-matrix interactions, and thus may be an important factor controlling the response of activated lymphocytes.
Santos-Argumedo
L
L
Department of Cell Biology, Centro de Investigación y Estudios Avanzados del IPN, Surrey, México DF, Mexico.
Kincade
P W
PW
Partida-Sánchez
S
S
Parkhouse
R M
RM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D048429:Cell Size / Q000276:immunology; D003712:Dendrites / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D018960:Hyaluronan Receptors / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D018960:Hyaluronan Receptors; D008562:Membrane Glycoproteins