Culture-associated enhancement of LECAM-1 expression by lymphocytes and partial inhibition of enhancement by IL-4.
Recent studies have shown that the human leukocyte endothelial cell adhesion molecule-1 (LECAM-1) functions as a homing receptor, mediating leukocyte binding to high endothelial venules in peripheral lymph nodes. Increasing evidence has demonstrated that cytokines, such as IL-4, can modulate the expression of surface proteins such as homing receptors on a variety of cells. We thus investigated the modulatory effects of cytokines on LECAM-1 expression by lymphocytes using single- and dual-color flow cytometry. We found that the density of LECAM-1 expression increased markedly during 3 days of culture and that this culture-associated enhancement (CAE) of LECAM-1 expression was significantly inhibited by IL-4. B cells and both major T cell subsets (CD4, CD8) exhibited CAE of LECAM-1 expression, but the inhibitory effect of IL-4 on this response occurred only in the T cell populations. The inhibitory effect of IL-4 on enhanced LECAM-1 expression was reversible, and characterized all 3 LECAM-1 epitopes assessed. Natural killer cells, in contrast, did not exhibit CAE of LECAM-1 expression, and IL-4 had no modulatory effect on LECAM-1 expression by these cells. Another adhesion molecule, CD44, showed enhanced expression during culture, but this enhancement was not inhibited by IL-4. The results show that LECAM-1 expression by T and B lymphocytes is significantly increased during culture and that the inhibitory effect of IL-4 on this increase is restricted to T cells. These findings suggest that IL-4, generated during an immune response, may play a role in regulating the migration and localization of T lymphocytes to lymphoid tissues.
American Red Cross Blood Services, Los Angeles, CA 90006.
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Jensen
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Prince
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D001402:B-Lymphocytes / Q000187:drug effects*; D017252:CD3 Complex; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D005434:Flow Cytometry; D006649:Histocompatibility Antigens; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects; D019041:L-Selectin; D017493:Leukocyte Common Antigens; D008562:Membrane Glycoproteins / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015815:Cell Adhesion Molecules; D016207:Cytokines; D006649:Histocompatibility Antigens; D008562:Membrane Glycoproteins; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; D019041:L-Selectin; D015847:Interleukin-4; D017493:Leukocyte Common Antigens