In vivo cross-priming of MHC class I-restricted antigens requires the TAP transporter

Alex Y.C. Huang, Allen T. Bruce, Drew M. Pardoll, Hyam I. Levitsky

Research output: Contribution to journalArticle


Recent in vitro evidence suggests two alternative mechanisms by which bone marrow-derived APCs may process exogenous antigens for presentation to CTL in vivo, a phenomenon termed cross-priming. Although in vitro studies have suggested that both TAP-dependent and TAP-independent pathways exist, we have now demonstrated an absolute requirement for a functional TAP for cross-priming to occur in vivo. Bone marrow chimeras reconstituted with marrow from TAP-defective donors develop functional CD8+ CTL, but have APCs with disrupted TAP function. In such chimeras, in vivo priming of naive CTL was observed when antigen was targeted to the ER in a TAP-independent fashion, but cross-priming could not be demonstrated. These results support the TAP-dependent mechanism of cross-priming.

Original languageEnglish (US)
Pages (from-to)349-355
Number of pages7
Issue number4
StatePublished - Apr 1996


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Infectious Diseases

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