The TCR/CD3 complex is a multimeric complex composed of molecules which are responsible for antigen binding signal transduction. Recent evidence suggest that on T cells interacting with antigen presenting cells, the CD8 or CD4 molecules become associated with this complex. The CD8 and CD4 molecules are associated with a protein tyrosine kinase, p56lck, thus on activated T cells CD8 or CD4 may mediate signalling through the TCR/CD3 complex. A number of systems have been developed to investigate the role of CD8, or other molecules, in T cell recognition and activation. Many of these systems have relied upon treatment with antibodies to CD8 to mimic the effect of binding physiologic ligand. We feel that a more ideal system to investigate the role of CD8 is a physiological situation in which the only variable is CD8 engagement. Through our recent studies which identified the region on MHC class I molecules which interacts with CD8, we have established a system to examine the contribution of CD8 to T cell activation upon interaction with physiologic ligand on antigen presenting cells. A comparative analysis of the response of the same T cell clone to interaction with APC's expressing either the wild type or mutant molecule will allow us to define the contribution of Cd8 mediated signal transduction to T cell activation. We will analyze T cell activation in this system by using measurable parameters indicative of the activation of the PtdInsP2 hydrolysis pathway; protein tyrosine kinase activity; and receptor redistribution, and correlate these events with induction of effector function in the T cell. Furthermore, the derivation of transgenic mouse lines which express either the wild type or mutant class I molecule will enable us to examine the role of CD8 in thymic selection events. We feel that these studies constitute a powerful approach to define the role of CD8 mediated signal transduction in activation of T cells at different stages of differentiation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI028115-07
Application #
2064261
Study Section
Immunobiology Study Section (IMB)
Project Start
1988-09-01
Project End
1996-07-31
Budget Start
1994-08-01
Budget End
1995-07-31
Support Year
7
Fiscal Year
1994
Total Cost
Indirect Cost
Name
National Jewish Health
Department
Type
DUNS #
City
Denver
State
CO
Country
United States
Zip Code
80206
Smith, P A; Potter, T A (1998) Alloreactive T cells that do not require TCR and CD8 coengagement are present in naive mice and contribute to graft rejection. J Immunol 160:5382-9
Smith, P A; Brunmark, A; Jackson, M R et al. (1997) Peptide-independent recognition by alloreactive cytotoxic T lymphocytes (CTL). J Exp Med 185:1023-33
Cook, J L; Potter, T A; Bellgrau, D et al. (1996) E1A oncogene expression in target cells induces cytolytic susceptibility at a post-recognition stage in the interaction with killer lymphocytes. Oncogene 13:833-42
Sawyer, R T; Drevets, D A; Campbell, P A et al. (1996) Internalin A can mediate phagocytosis of Listeria monocytogenes by mouse macrophage cell lines. J Leukoc Biol 60:603-10
Zwickey, H L; Potter, T A (1996) Peptide epitopes from noncytosolic Listeria monocytogenes can be presented by major histocompatibility complex class I molecules. Infect Immun 64:1870-2
Knall, C; Smith, P A; Potter, T A (1995) CD8-dependent CTL require co-engagement of CD8 and the TCR for phosphatidylinositol hydrolysis, but CD8-independent CTL do not and can kill in the absence of phosphatidylinositol hydrolysis. Int Immunol 7:995-1004
Drevets, D A; Sawyer, R T; Potter, T A et al. (1995) Listeria monocytogenes infects human endothelial cells by two distinct mechanisms. Infect Immun 63:4268-76
Knall, C; Ingold, A; Potter, T A (1994) Analysis of coreceptor versus accessory molecule function of CD8 as a correlate of exogenous peptide concentration. Mol Immunol 31:875-83
Connolly, J M; Hansen, T H; Ingold, A L et al. (1990) Recognition by CD8 on cytotoxic T lymphocytes is ablated by several substitutions in the class I alpha 3 domain: CD8 and the T-cell receptor recognize the same class I molecule. Proc Natl Acad Sci U S A 87:2137-41