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1994-08-09
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Document 0192
DOCN M9480192
TI Differential CD4-dependent regulation of naive and memory CD4+ T cell
adhesion is not related to differences in expression and function of CD4
and p56lck.
DT 9410
AU Lecomte O; Hivroz C; Mazerolles F; Fischer A; INSERM U132, Hopital
Necker-Enfants Malades, Paris, France.
SO Int Immunol. 1994 Apr;6(4):551-9. Unique Identifier : AIDSLINE
MED/94289336
AB We have previously reported that antigen-independent adhesion of CD45RO+
memory CD4+ T cells to B cells is negatively regulated by CD4-MHC class
II interaction, whereas that of CD45RA+ naive CD4+ T cells is not. We
have now found that both cross-linking of CD4 ligands [anti-CD4 mAbs,
HIV gp160 (env) protein and a 12mer peptide encompassing the 35-46
sequence of the HLA-DR beta 1 domain] on CD4+ naive T cells and
activation-induced conversion of naive CD4+ T cells to memory T cells
leads to CD4-dependent down-regulation of adhesion. To further elucidate
CD4-dependent differential regulation of naive and memory T cell
adhesion to B cells, we investigated the expression and function of CD4
and p56lck, a tyrosine kinase associated with the cytoplasmic domain of
CD4. p56lck tyrosine kinase activity was equally enhanced by anti-CD4
mAbs and gp160 (120) in the two subsets. Furthermore, cell-surface CD4
down-modulation by phorbol myristate acetate or anti-CD4 mAbs was
similar in the two subsets, which express the same amounts of both
cell-surface CD4 and CD4-associated p56lck. Finally, the pattern of
tyrosine phosphorylation of cellular proteins induced by gp120 (160) was
similar in the two subsets. Taken together, these results indicate that
the different sensitivity of naive and memory CD4+ T cells to
CD4-dependent regulation of adhesion is not accounted for by differences
in the tyrosine kinase activity of p56lck; it probably, therefore,
involves a step downstream of p56lck or another pathway differentially
used in naive and memory CD4+ T cells.
DE Amino Acid Sequence Antigens, CD4/BIOSYNTHESIS/*PHYSIOLOGY
B-Lymphocytes/PHYSIOLOGY Cell Adhesion/*IMMUNOLOGY Cross-Linking
Reagents Human Immunoblotting Lymphocyte Transformation Molecular
Sequence Data Precipitin Tests Protein-Tyrosine
Kinase/BIOSYNTHESIS/*PHYSIOLOGY Support, Non-U.S. Gov't T4
Lymphocytes/*PHYSIOLOGY JOURNAL ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).