RT Journal Article SR Electronic T1 Expression and presentation of endogenous mouse mammary tumor virus superantigens by thymic and splenic dendritic cells and B cells. JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 2789 OP 2794 VO 157 IS 7 A1 Ardavín, C A1 Waanders, G A1 Ferrero, I A1 Anjuère, F A1 Acha-Orbea, H A1 MacDonald, H R YR 1996 UL http://www.jimmunol.org/content/157/7/2789.abstract AB Tolerance against superantigens (SAgs) encoded by endogenous mouse mammary tumor virus (Mtv) loci involves the intrathymic deletion of SAg-reactive T cells expressing a particular TCR V beta-chain, presumably upon presentation of the SAg by specialized APC. However, although the role of dendritic cells (DC) in the induction of tolerance against conventional Ags has been demonstrated, little is known about the role played by DC in tolerance induction against Mtv SAgs. Moreover, there is conflicting evidence concerning the capacity of DC to express and present Mtv SAgs. In this report we have analyzed the expression of Mtv SAgs in highly purified thymic and splenic DC and B cells by reverse transcriptase-PCR, using primers amplifying Mtv SAg-specific spliced mRNAs. DC express Mtv SAgs at levels comparable to B cells, but display a differential expression pattern of the various Mtv loci compared with B cells. Furthermore, our results show that DC are able to induce the deletion of SAg-reactive thymocytes in an in vitro assay, indicating that Mtv SAgs are functionally expressed on the DC surface. Collectively, our data are consistent with the hypothesis that DC play a role in the induction of intrathymic tolerance to Mtv SAgs.