Cellular interactions between antigen (Ag)-specific T cells and antigen-presenting cells (APCs) can trigger either productive immune responses or aborted immune responses. These diverse biologic outcomes are determined by the complex integration of signals that are delivered upon the ligation of multiple receptors on the membrane of T cells with their counter receptors on the membrane of APCs. Uncovering the complex integrated cellular and molecular mechanisms, that determine the fate of the interacting cells, is the long term objective of these studies. Using novel 3-D digital imaging of T-APC conjugates it was recently shown that signaling and adhesion proteins are recruited to the cell contacts and form spatially segregated Supra-Molecular Activation Clusters (SMACs). This application is highly focused on the structure and function of the c-SMAC, which is the site of TCR engagement and activation. The central premise of this proposal is that TCR associated activation events are spatially and temporally orchestrated in the newly discovered c-SMAC. To test this hypothesis we will combine the use of T cell transgenic mice and multi-dimensional imaging and will define the 4-dimensional molecular translocations and association of four key activation receptors in the c-SMAC: TCR, CD45, CD4 and CD28 during T-APC interactions. These studies will be followed by derivative experiments to determine the mechanisms of association of each of these receptors with the c-SMAC and their physiological significance.
The specific aims are:
Aim 1. To determine the precise temporal and 3-dimensional molecular composition of c-SMACs in cell conjugates formed between T cells from TCR trangenic mice and B-APCs.
Aim 2. To study the mechanisms that cause the transient colocalization of CD45 with Ag-bound TCR and Lck in early c-SMACs and to assess the functional significance of these translocations.
Aim 3. To study the mechanisms that cause the transient early association of CD4 with the engaged TCR and Class II in c-SMACs, using TCR and CD4 tailless transgenic mice.
Aim 4. To study the mechanisms responsible for the association of CD28 with the engaged TCR in the cSMAC and the role of c-SMAC-associated CD28 in T cell activation. These novel studies would provide the first 4-dimensional view of T-APC interactions and, in combination with genetic and functional studies, are very likely to generate significant better understanding of the integrated events that properly regulate immune responses. This new knowledge may be useful in future designs of better immune surveillance protocols, immunosupression drugs and new vaccines.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
3R37AI023764-19S1
Application #
7122279
Study Section
Immunobiology Study Section (IMB)
Program Officer
Nabavi, Nasrin N
Project Start
1986-09-01
Project End
2005-09-19
Budget Start
2005-04-01
Budget End
2005-09-19
Support Year
19
Fiscal Year
2005
Total Cost
$182,779
Indirect Cost
Name
Johns Hopkins University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Schaefer, Brian C; Kappler, John W; Kupfer, Abraham et al. (2004) Complex and dynamic redistribution of NF-kappaB signaling intermediates in response to T cell receptor stimulation. Proc Natl Acad Sci U S A 101:1004-9
Miranda, Luis R; Schaefer, Brian C; Kupfer, Abraham et al. (2002) Cell surface expression of the HIV-1 envelope glycoproteins is directed from intracellular CTLA-4-containing regulated secretory granules. Proc Natl Acad Sci U S A 99:8031-6
Sperling, A I; Sedy, J R; Manjunath, N et al. (1998) TCR signaling induces selective exclusion of CD43 from the T cell-antigen-presenting cell contact site. J Immunol 161:6459-62
Nagasawa, M; Melamed, I; Kupfer, A et al. (1997) Rapid nuclear translocation and increased activity of cyclin-dependent kinase 6 after T cell activation. J Immunol 158:5146-54
Sinensky, M; Fantle, K; Trujillo, M et al. (1994) The processing pathway of prelamin A. J Cell Sci 107 ( Pt 1):61-7
Kupfer, H; Monks, C R; Kupfer, A (1994) Small splenic B cells that bind to antigen-specific T helper (Th) cells and face the site of cytokine production in the Th cells selectively proliferate: immunofluorescence microscopic studies of Th-B antigen-presenting cell interactions. J Exp Med 179:1507-15
Kupfer, A; Mosmann, T R; Kupfer, H (1991) Polarized expression of cytokines in cell conjugates of helper T cells and splenic B cells. Proc Natl Acad Sci U S A 88:775-9
Podack, E R; Kupfer, A (1991) T-cell effector functions: mechanisms for delivery of cytotoxicity and help. Annu Rev Cell Biol 7:479-504
Kupfer, A; Burn, P; Singer, S J (1990) The PMA-induced specific association of LFA-1 and talin in intact cloned T helper cells. J Mol Cell Immunol 4:317-25
Kupfer, A; Singer, S J (1989) The specific interaction of helper T cells and antigen-presenting B cells. IV. Membrane and cytoskeletal reorganizations in the bound T cell as a function of antigen dose. J Exp Med 170:1697-713

Showing the most recent 10 out of 15 publications