|
|
||||||||
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138
The T cell coreceptors CD4 and CD8 enhance T cell responses to TCR signals by participating in complexes containing TCR, coreceptor, and MHC molecules. These ternary complexes are also hypothesized to play a seminal role during T cell development, although the precise timing, frequency, and consequences of TCR-coreceptor-MHC interactions during positive selection and lineage commitment remain unclear. To address these issues, we designed transgenic mice expressing mutant I-Ek molecules with reduced CD4-binding capability. These transgenic lines were crossed to three different lines of I-Ek-specific TCR transgenic mice, and the efficiency of production of CD4+ lineage cells in the doubly transgenic progeny was assessed. Surprisingly, replacing wild-type I-Ek molecules with these mutant molecules did not affect the production of CD4+CD8- thymocytes or CD4+ peripheral T cells expressing any of the three TCRs examined. These data, when considered together with other experiments addressing the role of coreceptor during development, suggest that not all MHC class II-specific thymocytes require optimal and simultaneous TCR-CD4-MHC interactions to mature. Alternatively, it is possible that these particular alterations of I-Ek do not disrupt the CD4-MHC interaction adequately, potentially indicating functional differences between I-A and I-E MHC class II molecules.
This article has been cited by other articles:
![]() |
P. R. Menges, S. A. Jenks, E. K. Bikoff, D. R. Friedmann, Z. A. G. Knowlden, and A. J. Sant An MHC Class II Restriction Bias in CD4 T Cell Responses toward I-A Is Altered to I-E in DM-Deficient Mice J. Immunol., February 1, 2008; 180(3): 1619 - 1633. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Tatari-Calderone, J. L. Brogdon, K. W. Tinsley, A. Ramezani, and D. Leitenberg CD4-Dependent Signaling Is Required for a Late Checkpoint during Th2 Development Associated with Resistance to Activation-Induced Cell Death J. Immunol., November 1, 2005; 175(9): 5629 - 5636. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-J. Kim, D. Guo, and D. B. Sant'Angelo Coevolution of TCR-MHC interactions: Conserved MHC tertiary structure is not sufficient for interactions with the TCR PNAS, May 17, 2005; 102(20): 7263 - 7267. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Kao and P. M. Allen An antagonist peptide mediates positive selection and CD4 lineage commitment of MHC class II-restricted T cells in the absence of CD4 J. Exp. Med., January 3, 2005; 201(1): 149 - 158. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |