Reactivity of mouse T-cell hybridomas expressing human V beta gene segments with staphylococcal and streptococcal superantigens

A panel of 15 mouse T-cell hybridomas, each expressing a different human V beta gene segment (hV beta) in an otherwise mouse T-cell receptor (i.e., mouse cr chain and CD3 complex), was constructed by transfection of hV beta/mouse C beta chimeric T-cell receptor (TCR)-beta genes into a mouse T-cell hybridoma recipient lacking the endogenous TCR-beta chain. Several qualities that are conferred by the hV beta chain of the TCR are retained in the chimeric human-mouse TCR complex: a large panel of hV beta-specific antibodies specifically stained the hV beta expressed by the mouse T-cell hybridomas. Moreover, hV beta-transfected mouse cells could readily produce interleukin 2 when stimulated by superantigens presented by antigen-presenting cells. These characteristics made it possible to refine the reactivity of 17 superantigen preparations with the available transfected V beta s. Each superantigen gave a characteristic pattern of reactivity on the transfectants. Positive reactivities with some of these transfectants, which differ only by the expressed hV beta, demonstrate unambiguously the superantigenic character of a protein or fraction and its potential to react with the corresponding V beta s. Therefore, these hV beta-transfected cells constituted a valuable tool for determining ''specificity fingerprints'' of known or putative superantigens, First, commonly used, commercially available superantigens such as staphylococcal enterotoxin B and toxic shock syndrome toxin-1 (TSST-1) showed additional V beta reactivities, compared with those of their recombinant counterparts, This stresses the importance of using defined preparations of superantigens for the definition of V beta specificities. Second, the stimulatory pattern of a strain of Streptococcus pyogenes demonstrated that this strain, unlike others, produces a potent V beta 8-specific superantigen that is as yet undefined at the molecular level.