We report a de novo -assembled draft genome sequence of the Indian Staphylococcus aureus type 88 (ST88) strain LVP-7, isolated from an ocular infection. The harbors Panton-Valentine leukocidin phage, V staphylococcal cassette chromosome mec element, delta-hemolysin-converting Newman phage ΦNM3, and pathogenicity island SaPI3, encoding superantigen enterotoxin B.

Superantigen bound to major histocompatibility complex (MHC) products have been shown to stimulate T cells in a V beta-specific manner. Mouse T cells bearing V beta 8.1 usually respond to the self superantigen, Mls-1a, whereas T cells bearing V beta 8.2a do not. Previously, using site-directed mutational analysis, we identified the residues of natural variants of T cell receptor (TCR) V beta 8....

Formation of the costimulatory axis between the B7-2 and CD28 coreceptors is critical for T-cell activation. Superantigens, Gram-positive bacterial virulence factors, cause toxic shock and sepsis by hyperinducing inflammatory cytokines. We report a novel role for costimulatory receptors CD28 and B7-2 as obligatory receptors for superantigens, rendering them therapeutic targets. We show that by ...

Recent studies have shown that only a subset of major histocompatibility complex (MHC) class II molecules are able to present bacterial superantigens to T cells, leading to the suggestion that class-II associated peptides may influence superantigen presentation. Here, we have assessed the potential role of peptides on superantigen presentation by (a) analyzing the ability of superantigens to bl...

Dendritic cells are a small subset of human blood mononuclear cells that are potent stimulators of several T cell functions. Here we show they are 10-50-fold more potent than monocytes or B cells in inducing T cell responses to a panel of superantigens. Furthermore, dendritic cells can present femtomolar concentrations of superantigen to T cells even at numbers where other antigen-presenting ce...

C3H/HeJ mice transmit a mouse mammary tumor virus from mother to pup in milk. The retrovirus infects mice shortly after birth and, when expressed in recipient mice, produces a V beta 14-specific superantigen. The consequences of such expression on V beta 14-bearing T cells are examined in this paper. Most cells bearing V beta 14 and either CD4 or CD8 are eliminated in the thymus. Some V beta 14...

Experimentally induced murine graft-vs.-host disease may be characterized by hypergammaglobulinemia, autoantibody formation, and immune complex-mediated organ system damage that mimics SLE. These autoimmune phenomena are mediated by abnormal Th-B cell cooperation, across MHC disparities, in which donor-derived allospecific Th cells recognize and interact with MHC class II antigens on the surfac...

Although superantigens and their molecular interactions with MHC class II molecules have been well characterized recently, little is known concerning the physiological function of different types of APC in inducing superantigen-mediated T cell activation. To evaluate the potential of nonhematopoetic cells to present superantigens to T cells, we have tested astrocytes as a typical "nonprofession...

AIM To construct the superantigen SEA (D227A) expression vector modulated by cis-acting element of AFP and express it specifically on AFP(+) hepatocellular carcinoma (HCC) cells. METHODS The enhancer and promoter of AFP gene, SEA (D227A) cDNA and linker-CD80tm were amplified by PCR. The gene segments mentioned above were cloned into the multiple cloning sites of retrovirus vector pLXSN to con...

Mouse mammary tumor virus (MMTV[SW]) encodes a superantigen expressed by infected B cells. It evokes an antibody response specific for viral envelope protein, indicating selective activation of antigen-specific B cells. The response to MMTV(SW) in draining lymph nodes was compared with the response to haptenated chicken gamma globulin (NP-CGG) using flow cytometry and immunohistology. T cell pr...