HLA class II molecules on monocytes regulate T cell proliferation through physical interaction in the CD3 activation pathway.

Journal Article (Journal Article)

HLA class II molecules are involved in the OKT3-induced T cell activation, since monoclonal antibodies (mAb) to monomorphic determinants of class II antigens are able to inhibit T cell proliferation. This effect involves several of the events leading to T cell activation and proliferation, i.e. interleukin (IL) 1, IL 6 and IL2 secretion and IL2 receptor expression. The main target of the inhibition is represented by monocytes, and the interference of anti-class II mAb in the direct interaction of monocytes with T cells is likely to play a relevant role in the inhibition mechanism. To test this hypothesis, we investigated in the present study the effect of anti-class II mAb on the proliferation of T cells stimulated with mAb OKT3 in the presence of paraformaldehyde-treated monocytes. We show that the inhibition of proliferation is specific and dose dependent, and seems to involve particular class II epitopes. Addition of fixed monocytes to inhibited T cell cultures restores proliferation to a moderate extent, only if monocytes are added within the first 12 h of culture, suggesting that class II antigens or spatially related molecules deliver signals concurrently with the mitogenic stimulus. The blocking capability of anti-class II mAb was not restricted to the CD4+ or the CD8+ T cell subsets, suggesting that, under inhibitory conditions, these mAb affect other structures on the T cell surface, relevant to the monocyte-T cell interaction.

Full Text

Duke Authors

Cited Authors

  • Ruggiero, G; Racioppi, L; Manzo, C; Pirozzi, G; D'Oro, U; Ferrone, S; Zappacosta, S; Fontana, S

Published Date

  • January 1, 1991

Published In

Volume / Issue

  • 21 / 1

Start / End Page

  • 29 - 33

PubMed ID

  • 1825060

International Standard Serial Number (ISSN)

  • 0014-2980

Digital Object Identifier (DOI)

  • 10.1002/eji.1830210106


  • eng

Conference Location

  • Germany