|
|
||||||||



Departments of
* Immunology and
Neuropharmacology, The Scripps Research Institute, La Jolla, CA 92037; and
Department of Microbiology and Immunology, University of Melbourne, Faculty of Medicine, Melbourne, Australia
Subtle differences oppose CD4+ to CD8+ T cell physiologies that lead to different arrays of effector functions. Interestingly, this dichotomy has also unexpected practical consequences such as the inefficacy of many MHC class II tetramers in detecting specific CD4+ T cells. As a mean to study the CD4+ anti-OVA response in H-2d and H-2b genetic backgrounds, we developed I-Ad- and I-Ab-OVA recombinant MHC monomers and tetramers. We were able to show that in this particular system, despite normal biological activity, MHC class II tetramers failed to stain specific T cells. This failure was shown to be associated with a lack of cooperation between binding sites within the tetramer as measured by surface plasmon resonance. This limited cooperativeness translated into a low "functional avidity" and very transient binding of the tetramers to T cells. To overcome this biophysical barrier, recombinant artificial APC that display MHC molecules in a lipid bilayer were developed. The plasticity and size of the MHC-bearing fluorescent liposomes allowed binding to Ag-specific T cells and the detection of low numbers of anti-OVA T cells following immunization. The same liposomes were able, at 37°C, to induce the full reorganization of the T cell signaling molecules and the formation of an immunological synapse. Artificial APC will allow T cell detection and the dissection of the molecular events of T cell activation and will help us understand the fundamental differences between CD4+ and CD8+ T cells.
This article has been cited by other articles:
![]() |
E. L. Masteller, M. R. Warner, Q. Tang, K. V. Tarbell, H. McDevitt, and J. A. Bluestone Expansion of Functional Endogenous Antigen-Specific CD4+CD25+ Regulatory T Cells from Nonobese Diabetic Mice J. Immunol., September 1, 2005; 175(5): 3053 - 3059. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. J. Prakken, R. Samodal, T. D. Le, F. Giannoni, G. P. Yung, J. Scavulli, D. Amox, S. Roord, I. de Kleer, D. Bonnin, et al. Epitope-specific immunotherapy induces immune deviation of proinflammatory T cells in rheumatoid arthritis PNAS, March 23, 2004; 101(12): 4228 - 4233. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |