A KINETIC COMPARATIVE-STUDY ON LYMPHOCYTE-RESPONSES TO SUPERANTIGEN AND PHYTOHEMAGGLUTININ - RECIPROCAL PRESENTATION OF SUPERANTIGEN ON THESURFACE OF ACTIVATED LYMPHOCYTES
S. Ijichi et al., A KINETIC COMPARATIVE-STUDY ON LYMPHOCYTE-RESPONSES TO SUPERANTIGEN AND PHYTOHEMAGGLUTININ - RECIPROCAL PRESENTATION OF SUPERANTIGEN ON THESURFACE OF ACTIVATED LYMPHOCYTES, Cellular immunology, 173(2), 1996, pp. 312-316
The kinetics of thymidine incorporation into fractionated T lymphocyte
s responding to bacterial super-antigens were compared to those of cel
ls activated by phytohemagglutinin (PMA), Evident differences between
the kinetics of cell proliferation induced by PHA-P and staphylococcal
enterotoxin B (SEE) emerged after Day 4 of culture, PHA-P-induced pro
liferative responses of peripheral blood mononuclear cells (PBMCs) and
fractionated cells were apparent on Day 4 because of the presence of
accessory cells in the initial cell suspensions. This gradually dimini
shed in correlation with the decline of accessory cells in the culture
s. The SEE-induced cell growth (PBMCs and CD4(+) cells), however, cont
inued until Day 9 of the culture, This finding suggests the reciprocal
usage of MMC class II molecules to present SEE by activated T lymphoc
ytes for superantigen-induced T cell activation and suggests that supe
rantigen-related immune activation may depend in part on the potential
of activated T lymphocytes to mediate reciprocal cell-to-cell interac
tions in the presence of superantigens. The decline observed in the CD
8(+) cell response to SEE and toxic shock syndrome toxin-l after Day 4
was revived by exogenous recombinant interleukin-2 (rIL-2) supplement
ation, suggesting that the consequent autocrine or paracrine secretion
of IL-2 from the responding cells is essential for subsequent cell pr
oliferation, SEE-induced cell proliferation was significantly suppress
ed by anti-CD11a (lymphocyte function-associated antigen-1; LFA-I, alp
ha-Chain) monoclonal antibody, and the inhibitory effect was most obvi
ous in 6-day cultured CD8(+) lymphocytes. The results suggest that the
lymphocyte response associated with the ceIl-to- cell copresentation
of superantigens involves LFA-1 molecules as an accessory factor, part
icularly ill CD8(+) lymphocytes. (C) Academic Press, Inc.