Antigen-independent adhesion of CD45RA (naive) and CD45RO (memory) CD4 T cells to B cells.
We found that naive (CD45RA+) CD4 T cells have a lower capacity of adhesion to Epstein-Barr virus (EBV) immortalized B cells than memory (CD45RO+) CD4 T cells, as judged by conjugate formation. This would appear to be due to differences in the expression of adhesion molecules [lymphocyte function-associated antigen (LFA)-1, CD2]. However, kinetic studies showed that the degree of adhesion of naive T cells to B cells was stable over 60 min while that of memory T cells, like that of unseparated CD4 T cells, was characterized by a rapid formation and rapid dissociation of conjugates. This could be explained by a difference in the sensitivity of naive and memory CD4 T cells to down-regulation of antigen-independent adhesion by CD4-MHC class II interaction. Indeed, memory T cells also adhered stably to MHC class II(-) B cells. The adhesion of memory T cells, but not naive T cells, to MHC class II(+) B cells was sensitive to inhibition by OKT4a an anti-CD4 antibody, human immunodeficiency (HIV) gp160 (env) protein and a 12-mer peptide encompassing the 35-46 sequence of the HLA, DR beta 1 domain and previously shown to inhibit activation of HLA class II-restricted CD4 T cell responses. Since MHC class II expression did not influence the degree of conjugate formation by naive or memory CD4 T cells with B cells, CD4-MHC class II interaction does not appear to be involved in binding itself, but may down-regulate the adhesion of memory but not naive CD4 T cells.(ABSTRACT TRUNCATED AT 250 WORDS)
INSERM U 132, Hôpital Necker-Enfants Malades, Paris, France.
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Lecomte
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Fischer
D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000276:immunology*; D001402:B-Lymphocytes / Q000502:physiology*; D015704:CD4 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002448:Cell Adhesion / Q000276:immunology; D005434:Flow Cytometry; D015686:Gene Products, env / Q000494:pharmacology; D019302:HIV Envelope Protein gp160; D006684:HLA-DR Antigens / Q000276:immunology; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D017493:Leukocyte Common Antigens; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000494:pharmacology
D015703:Antigens, CD; D015704:CD4 Antigens; D015686:Gene Products, env; D019302:HIV Envelope Protein gp160; D006684:HLA-DR Antigens; D006649:Histocompatibility Antigens; D011498:Protein Precursors; D017493:Leukocyte Common Antigens