Superantigens are microbial proteins that strongly stimulate T cells. We described previously that the Epstein-Barr virus (EBV) transactivates a superantigen encoded by the human endogenous retrovirus, HERV-K18. We now report that the transactivation is dependent upon the EBV latent cycle proteins. Moreover, LMP-2A is sufficient for induction of HERV-K18 superantigen activity.

Superantigens are defined by their ability to stimulate T cells based predominantly on their V beta expression and ability to delete T cells in the thymus when expressed endogenously. We show here that the expression of one endogenous superantigen, Etc-1, is controlled by the expression of the open reading frame region of the 3' long terminal repeat of the mouse mammary tumor proviral gene, Mtv...

Staphylococcal enterotoxins are bacterial products that display superantigen activity in vitro as well as in vivo. For instance, staphylococcal enterotoxin B (SEB) polyclonally activates T cells that bear the Vbeta8 gene segment of the TCR. SEB-activated T cells undergo a burst of proliferation that is followed by apoptosis. Using an in vivo adaptation of a fluorescent cell division monitoring ...

The production of superantigenic exotoxins by Gram positive bacteria underlies the pathology of toxic shock syndrome. Future treatment strategies for superantigen-mediated diseases are likely to be directed at blocking the three-way interaction between superantigen, T cell receptor and major histocompatibility class II molecule, which inititates an excessive and disordered inflammatory response...

Abstract T cell activation in the lymph node (LN) is critical to initiating adaptive immune responses vaccination, tumors, and infection. We previously demonstrated that cells from human tissue sites (blood, LNs, bone marrow, lung) undergo conserved state transitions during activation. However, these studies were performed suspension culture dissociated tissue, depleting spatial signaling contr...

Bacterial superantigens are potent T cell activators. In humans they cause toxic shock and scarlet fever, and they are implicated in Kawasaki's disease, autoimmunity, atopy, and sepsis. Their function remains unknown, but it may be to impair host immune responses increasing bacterial carriage and transmission. Regulatory (CD25(+)FOXP3(+)) T cells (Tregs) play a role in controlling inflammatory ...

T-cell-mediated antitumor effects play an important role clinically in allogeneic graft-versus-leukemia (GvL) reactivity, whereas T-cell-mediated antihost effects are associated with a risk of developing graft-versus-host (GvH) disease. GvL and GvH were compared in an animal tumor model system after the systemic transfer of allogeneic antitumor immune T lymphocytes from B10.D2 [H-2d; minor lymp...