Soluble peptide-MHC monomers cause activation of CD8+ T cells through transfer of the peptide to T cell MHC molecules.
T cell receptor (TCR)-mediated activation of CD4(+) T cells is known to require multivalent engagement of the TCR by, for example, oligomeric peptide-MHC complexes. In contrast, for CD8(+) T cells, there is evidence for TCR-mediated activation by univalent engagement of the TCR. We have here compared oligomeric and monomeric L(d) and K(b) peptide-MHC complexes and free peptide as stimulators of CD8(+) T cells expressing the 2C TCR. We found that the monomers are indeed effective in activating naive and effector CD8(+) T cells, but through an unexpected mechanism that involves transfer of peptide from soluble monomers to T cell endogenous MHC (K(b)) molecules. The result is that T cells, acting as antigen-presenting cells, are able to activate other naive T cells.
Ge
Qing
Q
Department of Biology, Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Stone
Jennifer D
JD
Thompson
M Todd
MT
Cochran
Jennifer R
JR
Rushe
Mia
M
Eisen
Herman N
HN
Chen
Jianzhu
J
Stern
Lawrence J
LJ
D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018448:Models, Immunological; D010455:Peptides / Q000737:chemistry* / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism
D015395:Histocompatibility Antigens Class I; D010455:Peptides; D011948:Receptors, Antigen, T-Cell