CD4-dependent and -independent association of protein tyrosine kinases to the T cell receptor/CD3 complex of CD4+ mouse T lymphocytes.
Eur J Immunol
; 26(6): 1228-34, 1996 Jun.
Article
em En
| MEDLINE
| ID: mdl-8647197
ABSTRACT
Tyrosine phosphorylation of different substrates is the earliest intracellular signal detected after T cell receptor (TcR) ligation. Several tyrosine kinases have been detected associated to the CD3-TcR complex in stimulated or unstimulated cells, including p56lck, p59fyn and ZAP-70. We have observed, in one mouse T helper CD4 T cell line, that most TcR- or CD3-associated tyrosine kinase activity comes from CD4p56lck (Diez-Orejas, R., Ballester, S., Feito, M. J., Ronda, M., Ojeda, G., Criado, G., Portolés, P. and Rojo, J. M., EMBO J. 1994. 13 90). To analyze whether this is a major way of tyrosine kinase association to the TcR in normal CD4+ T cells, we examined the nature and mode of association of tyrosine kinases to the TcR complex in normal spleen CD4+ T lymphocytes. Our results show that, in normal CD4+ T lymphocytes, as in CD4+ T cell lines, there is a stable and readily detectable association between CD4p56lck and the TcR/CD3 complex, as determined by in vitro kinase activity in immunoprecipitates from cell lysates. However, TcR/CD3 complexes from nature CD4+ lymphocytes have detectable amounts of p56lck associated in a CD4-independent manner, as shown by immunodepletion of the lysates with anti-CD4 antibodies. In addition, TcR/CD3 also bind p59fyn regardless of the presence of CD4. Conversely, we have observed that CD4 co-precipitates small quantities of p56fyn in a TcR/CD3-independent manner. Overall, our data suggest the existence of different possible molecular complexes between TcR/CD3, CD4 and their attending kinases, as well as some quantitative and qualitative differences between CD4+ T cells and CD4+ T cell lines in kinase association to the TcR/CD3 complex.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Tirosina Quinases
/
Linfócitos T CD4-Positivos
/
Antígenos CD4
/
Complexo CD3
Tipo de estudo:
Qualitative_research
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Eur J Immunol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Espanha