High levels of CD44 expression distinguish virgin from antigen-primed B cells.
The in vitro polyclonal stimulation of B cells through their surface immunoglobulin (Ig) induces substantial increases in CD44 protein levels within 24 hours, whereas other stimuli (e.g., lipopolysaccharide, phorbol 12,13 dibutyrate, and interleukin 4) fail to significantly upregulate CD44. The marked increase in CD44 protein expression on anti-Ig-treated B lymphocytes correlates with an increase in CD44-specific mRNA. Cell sorting experiments with B cells isolated from trinitrophenyl-keyhole limpet hemocyanin-immunized mice demonstrate that both short-term antigen-specific, IgG-secreting cells and long-term antigen-primed B cells are exclusively CD44high. We speculate that the rapid and sustained increase in CD44 expression mediated by surface Ig stimulation may alter the homing properties of antigen-primed B cells.
Camp
R L
RL
Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, New York 10021.
Kraus
T A
TA
Birkeland
M L
ML
Puré
E
E
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D016201:Receptors, Lymphocyte Homing / Q000096:biosynthesis* / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology; D015854:Up-Regulation
D008070:Lipopolysaccharides; D011947:Receptors, Antigen, B-Cell; D016201:Receptors, Lymphocyte Homing; D015847:Interleukin-4; D015240:Phorbol 12,13-Dibutyrate