@article {542751,
	title = {Rejection of mouse cardiac allografts by costimulation in trans.},
	journal = {J Immunol},
	volume = {167},
	number = {3},
	year = {2001},
	month = {2001 Aug 1},
	pages = {1174-8},
	abstract = {The activation of T cells by B7 costimulation in trans has been demonstrated in vitro, but the in vivo relevance is unknown. To study costimulation in trans of CD4(+) T cells in vivo, we performed cardiac transplants from B7-1/B7-2-deficient mice to recipients that do not express MHC class II molecules on peripheral APCs, but do have functional CD4(+) T cells (II(-)/4(+) mice). This model restricts the B7-dependent activation of CD4(+) T cells to costimulation in trans and excludes any contribution from indirect Ag presentation. We find that II(-)/4(+) recipients reject B7-deficient grafts as rapidly as wild-type grafts, suggesting that costimulation in trans can mediate rejection as potently as costimulation in cis. Treatment of II(-)/4(+) recipients of B7-deficient grafts with depleting Abs to CD4 or CD8 demonstrates that indirect Ag presentation to CD8(+) cells does not significantly contribute to rejection. This is the first demonstration that costimulation in trans can mediate an immune response in vivo and has important therapeutic implications.},
	keywords = {Animals, Antigen-Presenting Cells, Antigens, CD, Antigens, CD4, Antigens, CD80, Antigens, CD86, CD4-Positive T-Lymphocytes, CD8-Positive T-Lymphocytes, Cells, Cultured, Graft Rejection, Heart Transplantation, Histocompatibility Antigens Class II, Lymphocyte Activation, Lymphocyte Culture Test, Mixed, Male, Membrane Glycoproteins, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Knockout, Transplantation, Homologous},
	issn = {0022-1767},
	author = {Mandelbrot, D A and Kishimoto, K and Auchincloss, H and Sharpe, A. H. and Sayegh, M H}
}
