TY  - JOUR
PY  - 1994//
TI  - Control of differential CD4+ T lymphocyte behavior in vitro is dictated by the pattern of CD molecule involvement
JO  - Ciênc. cult. (Säo Paulo)
A1  - Reis, George A. dos
A1  - Palomo, Luis F.
A1  - Lopes, Marcela F.
A1  - Gomes, Nitza A.
A1  - Lima, Célio Freire de
A1  - Peçanha, Lígia T.
SP  - 358
EP  - 62
VL  - 46
IS  - 5/6
N2  - T lymphocyte responses in vitro are not all-or-none choices to environmental stimulation, but follow at least three distinct patterns: full activation and expansion, anergy induction, and receptor-mediated suicide by apoptosis. In vitro model systems were devised to investigate the differential control of T cell responses by surface CD activation molecules, CD4+ T cells from T. cruzi-infected mice are severely impaired in their proliferative response to TCR stimulation. TCR stimulation leads to CD4+ T cell suicide by apoptosis, but CD3 stimulation is less efficient in this effect. Triggering of normal CD4 T cells through CD4 coincident with TCR activation, does not affect proliferative responses, but induces marked morphological changes in the T cells, which become adherent, form extended cytoplasmic projections, and acquire motile behavior. This response requires IL4 production, and can be markedly upregulated by exogenous IL4. Autoreactive CD4 T cell functioning can help syngeneic B cells to produce a TH2 pattern of immunoglobulin isotypes following stimulation by a thymus independent antigen. These results indicate that distinct patterns of functional behavior in vitro can be induced, depending both on the past experience of the T cell and on the exact array of stimulatory CD antigens engaged in the process of activation. The relevance of these constraints in generating variable behavior for immunoregulation is discussed.<p /> <p>Language: en</p>
LA  - en
SN  - 0009-6725
UR  - http://dx.doi.org/
ID  - ref1
ER  -