The CD8 cell surface glycoprotein is expressed on subsets of T cells, natural killer cells, and dendritic cells at various stages of differentiation. It functions as both an adhesion and a signaling molecule on cytotoxic and regulatory T cells. CD8 is expressed as either an alpha/alpha (a/a) homodimer or as an alpha/beta (a/b) heterodimer. These two forms of CD8 are differentially expressed on certain cell types and are functionally distinct. One of the CD8 ligands is the major histocompatibility class I molecules to which the T cell receptor also binds. The goals of the proposal are to determine the structural basis for CD8-MHC class I interaction in molecular detail and to determine if there are differences in this interaction between the two forms of CD8 that may account for their functional differences. Another goal is to determine the structural basis for the interaction between CD8 on regulatory T cells with a 180 kD ligand expressed on intestinal epithelial cells. Differences in interaction between MHC class I and CD8 on cytotoxic cells vs. the 180 kD protein and CD8 on regulatory T cells may be partially responsible for alternative pathways of T-cell activation and thus functional differences between these two cell types. A new class of antigen cell surface molecules which present antigens to T cells is the CD1 family of proteins. These proteins appear to be ligands for CD8. It is planned to determine the structural basis for these interactions as well. A combination of approaches will be used for these studies. Cell-cell adhesion assays between cells transfected with either CD8 or ligands will be performed to demonstrate direct interactions. Mutagenesis studies will be used to identify critical residues for protein-protein interactions and complementary mutational analysis for determining topology of the interactions. Affinities and association and dissociation rate constants will be determined using surface plasmon resonance detection with a BIAcore. The work proposed will extend understanding of the basic mechanism of immune recognition, a crucial part of host defense against cancer and infection. Clinically, the structure/function studies carried out in this proposal will potentially allow for the design of therapeutic proteins bearing CD8 Ig-like domains that may be used to modulate specific CD8-ligand interactions and the T-cell activation events which are triggered by these interactions with CD8.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
3R01CA048115-10S1
Application #
6143782
Study Section
Allergy and Immunology Study Section (ALY)
Project Start
1988-07-01
Project End
2002-08-31
Budget Start
1999-09-01
Budget End
2000-08-31
Support Year
10
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Yale University
Department
Pathology
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Thakral, Deepshi; Dobbins, Jessica; Devine, Lesley et al. (2008) Differential expression of the human CD8beta splice variants and regulation of the M-2 isoform by ubiquitination. J Immunol 180:7431-42
Liu, Wenzhong; Mani, Sheida; Davis, Nicole R et al. (2008) Mutation in EGFP domain of LDL receptor-related protein 6 impairs cellular LDL clearance. Circ Res 103:1280-8
Devine, Lesley; Thakral, Deepshi; Nag, Shanta et al. (2006) Mapping the binding site on CD8 beta for MHC class I reveals mutants with enhanced binding. J Immunol 177:3930-8
Attinger, Antoine; Devine, Lesley; Wang-Zhu, Yiran et al. (2005) Molecular basis for the high affinity interaction between the thymic leukemia antigen and the CD8alphaalpha molecule. J Immunol 174:3501-7
Kieffer, Lynda J; Greally, John M; Landres, Inna et al. (2002) Identification of a candidate regulatory region in the human CD8 gene complex by colocalization of DNase I hypersensitive sites and matrix attachment regions which bind SATB1 and GATA-3. J Immunol 168:3915-22
Devine, Lesley; Rogozinski, Linda; Naidenko, Olga V et al. (2002) The complementarity-determining region-like loops of CD8 alpha interact differently with beta 2-microglobulin of the class I molecules H-2Kb and thymic leukemia antigen, while similarly with their alpha 3 domains. J Immunol 168:3881-6
Campbell, N A; Park, M S; Toy, L S et al. (2002) A non-class I MHC intestinal epithelial surface glycoprotein, gp180, binds to CD8. Clin Immunol 102:267-74
Daniels, M A; Devine, L; Miller, J D et al. (2001) CD8 binding to MHC class I molecules is influenced by T cell maturation and glycosylation. Immunity 15:1051-61
Kim, S K; DeMars, R (2001) Epitope clusters in the major outer membrane protein of Chlamydia trachomatis. Curr Opin Immunol 13:429-36
Kim, S K; Devine, L; Angevine, M et al. (2000) Direct detection and magnetic isolation of Chlamydia trachomatis major outer membrane protein-specific CD8+ CTLs with HLA class I tetramers. J Immunol 165:7285-92

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