Tamar L. Collins

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The lymphoid-specific tyrosine kinase p56lck (Lck) is critical for the development and activation of T lymphocytes, and Lck kinase activity has been implicated in both T-cell antigen receptor/CD3- and CD4-mediated signaling. CD4-dependent T-cell activation has been demonstrated to be dependent upon the association of CD4 with Lck. To examine the role of the(More)
Lymphocyte chemoattractant factor (LCF) is a polypeptide cytokine which induces both cell motility and activation of T lymphocytes. These LCF-induced events demonstrate an absolute requirement for the cell surface expression of CD4. Because many CD4-mediated T lymphocyte activation events have been demonstrated to require the association of the src-related(More)
CD4 is a cell surface glycoprotein expressed by a subset of T lymphocytes and functions to enhance T-cell activation. CD4 is noncovalently associated via the cytoplasmic domain with the protein-tyrosine kinase p56lck, a member of the src protein-tyrosine kinase family. Upon activation of protein kinase C by phorbol ester, CD4 is phosphorylated on(More)
By fluorescence resonance energy transfer, we have previously demonstrated that upon anti-CD3 mAb-mediated activation of a murine T cell hybridoma expressing human CD4, CD4 moves into close association with the TCR/CD3 complex. It was shown that this association between CD4 and the TCR/CD3 complex was dependent upon the presence of an intact CD4 cytoplasmic(More)
To test the hypothesis that resting and previously activated B lymphocytes differ in their proliferative and differentiative responses to various Th cell-derived stimuli, we have examined the interactions of purified small (resting) and large (activated) murine B cells with rabbit Ig-specific Th1 and Th2 clones in the presence of the Ag analogue, rabbit(More)
The past several years have seen significant progress in understanding the role of T lymphocyte coreceptors in adhesion and activation. New insights have been gained in several areas: the avidity regulation of beta 1 and beta 2 integrins and their role in signal transduction; the regulation of CD8 avidity; the role of Lck in CD4 coreceptor activity; and the(More)
The CD4 molecule plays an important role in the development of CD4+T lymphocytes and it also acts as a coreceptor to enhance responses mediated via the TCR. It is now established that CD4 functions both as an adhesion molecule favoring the T cell: APC interaction and as a signaling molecule. The coreceptor function mediated via CD4 depends on its(More)
Many protein tyrosine phosphorylation events that occur as a result of T cell receptor (TCR) stimulation are enhanced when CD4 is co-cross-linked with the TCR, and this increased phosphorylation is thought to be a mechanism by which T cell functions are augmented by CD4. Such enhanced tyrosine phosphorylation was originally attributed to the kinase activity(More)
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