A TOXIC-SHOCK-SYNDROME-TOXIN-1 PEPTIDE THAT SHOWS HOMOLOGY TO AMINO-ACIDS-180-193 OF MYCOBACTERIAL HEAT-SHOCK PROTEIN-65 IS PRESENTED AS CONVENTIONAL ANTIGEN
N. Ramesh et al., A TOXIC-SHOCK-SYNDROME-TOXIN-1 PEPTIDE THAT SHOWS HOMOLOGY TO AMINO-ACIDS-180-193 OF MYCOBACTERIAL HEAT-SHOCK PROTEIN-65 IS PRESENTED AS CONVENTIONAL ANTIGEN, Immunological investigations, 23(6-7), 1994, pp. 381-391
Peripheral blood mononuclear cells (PBMC) from the majority of adults
(12 out of 18 subjects tested) showed an in vitro proliferative respon
se to a 20 amino acid long peptide (peptide 1, a.a 18-37) derived from
TSST-1. In contrast, thymocytes and PBMC from cord blood did not prol
iferate to this peptide. TSST-1 peptide 1 did not induce IL-1 beta mRN
A in monocytes indicating that it does not behave as a superantigen. P
roliferation of PBMC to peptide 1 could be blocked by anti-HLA-DR, but
not by anti-HLA DP or DQ monoclonal antibodies suggesting that HLA-DR
molecules are the restriction elements for the recognition of this pe
ptide by T cells. Studies with subjects of known HLA-DR types showed t
hat all types tested are capable of responding to this peptide. Peptid
e 1 shows homology to a.a 180-193 of mycobacterial hsp 65 and was show
n to stimulate the proliferation of T cell lines and T cell clone spec
ific for the purified protein derivative (PPD) of Mycobacterium tuberc
ulosis. This cross reactivity may confer on TSST-1 the potential to tr
igger self reactivity and may also contribute to the natural immunity
against TSST-1.