HLA class II molecules transduce accessory signals affecting the CD3 but not the interleukin-2 activation pathway in T blasts.


Journal Article

MHC class II molecules play a central role in the control of the immune response, but their biologic function and mechanism of action on the surface of activated human T lymphocytes are not entirely understood. In our study, the functional role of HLA class II molecules in T-blast proliferation was investigated by analyzing in parallel the IL-2- and CD3-driven activation pathways. The results indicate that the cross-linking of class II and CD3 molecules significantly increased the CD3-mediated T-blast proliferation, while no effect was observed on the IL-2-driven cell activation. This phenomenon was not confined to either CD4+ or CD8+ subsets nor was specifically affected by CD45 triggering. Biochemical studies showed that signaling via MHC class II molecules in T blasts led to PKC membrane translocation and IP accumulation. The simultaneous triggering of CD3 and HLA class II molecules led to a synergistic effect on IP accumulation but did not increase the CD3-mediated PKC membrane translocation. Our data suggest that HLA class II molecules are involved in T-cell-T-cell interactions and can mediate accessory signals, affecting the T-lymphocyte activation state.

Full Text

Duke Authors

Cited Authors

  • Di Rosa, F; D'Oro, U; Ruggiero, G; Racioppi, L; Acquaviva, A; Ferrone, S; Fontana, S; Zappacosta, S

Published Date

  • December 1993

Published In

Volume / Issue

  • 38 / 4

Start / End Page

  • 251 - 260

PubMed ID

  • 8138420

Pubmed Central ID

  • 8138420

International Standard Serial Number (ISSN)

  • 0198-8859

Digital Object Identifier (DOI)

  • 10.1016/0198-8859(93)90552-c


  • eng

Conference Location

  • United States