A modification of the polymerase chain reaction has been used to establish the fact that a collection of Staphylococcus aureus toxins are "superantigens," each of which interacts with the T-cell a4i receptor of human T cells by means of a specific set of V,8 elements.The antigen receptor [T-cell receptor (TCR)] on most peripheral T cells is a heterodimer made up of a and P chains. Five germ-line-encoded variable elements (Va, Ja, Vp, Dp, and JP) as well as non-germ-line-encoded amino acids contribute to the receptor combining site (1-4). The ligands for aB TCRs are combinations of antigen-derived peptides, bound to major histocompatibility complex proteins (MHC) (5)(6)(7)(8). Usually the specificity of TCRs for antigen plus MHC is determined by all of the variable elements of both a and p chains (1-4). Exceptions to this rule have, however, recently been documented by us and others (9-18). In the examples studied so far, the exceptions involve an antigen/MHC combination that can stimulate T cells bearing a particular VP, almost regardless of the composition of the rest of the receptor on these cells. We have suggested the term "superantigen" to describe receptor ligands of this type. These superantigens and the VP elements that engage them have been well documented in mice with the help of an increasing number of VP-specific antibodies and DNA probes.Some superantigens are endogenously synthesized-for example, a mouse B-cell-derived self-superantigen bound to IE reacts with nearly all T cells bearing Vl17a and mice that express IE delete nearly all V,817a' T cells (9, 10). Exogenous superantigens have also been described. We and others have recently shown that some bacterial proteins are also able to stimulate T cells in a Vp-specific fashion (15-19). For example, Staphylococcus aureus enterotoxin B (SEB) stimulates mouse T cells bearing Vp83, and has no effect on most other cells. Since the S. aureus toxins are important contributors to morbidity and mortality in man (20), we wished to extend our studies on bacterial superantigens to human T cells. In an initial study, we used monoclonal antibodies (mAbs) to four human VP elements to show that T cells expressing these VP elements were differentially stimulated by a panel of S. aureus toxins (18). However, since there are at least 20 V, families in human (2, 21), we were limited by the lack of a complete set of anti-VP mAbs. We have, therefore, modified the methodology of the polymerase chain reaction (PCR) (22,23) MATERIALS AND METHODSPreparation of RNA and cDNA Synthesis. Total RNA was prepared from anti-CD3-stimulated peripheral T cells as described (18,24). Two micrograms of total RNA was used for the synthesis of first strand cDNA using reverse transcriptase (Amersham) and random hexanucleotides. The reaction was stopped by heating for 5 min at 950C before PCR.Amplification of cDNA by PCR and Quantitation of Amplified Products. One-twentieth of each cDNA sample was coamplified using a Vp-specific primer with a C,3 primer and two Ca primers (Table 1...

The staphylococcal toxins are responsible for a number of diseases in man and other animals. Many of them have also long been known to be powerful T cell stimulants. They do not, however, stimulate all T cells. On the contrary, each toxin reacts with human T cells bearing particular V beta sequences as part of their receptors for major histocompatibility complex protein-associated antigen. The specificity of these toxins for V beta s puts them in the recently described class of superantigens and may account for the differential sensitivity of different individuals to the toxic effects of these proteins.

We describe a 90-kDa lymphocyte surface glycoprotein, recognized by the monoclonal antibody Hermes-1, that is involved in endothelial cell recognition and lymphocyte trafficking in man. This molecule is selectively expressed on normal or transformed lymphoid cells that are able to recognize and bind to high endothelial venules (HEV, specialized vessels that mediate lymphocyte exit from the blood into lymphoid organs); appears to be linked to HEV recognition function since, in fluorescence-activated cell sorting of variants of a cloned cell line, HEV binding ability co-selects with the Hermes-1 antigen; bears the predominant cell surface epitopes recognized by heterologous anti-human lymphocyte antibodies able to interfere with lymphocyte binding to HEV; and is structurally similar to a previously described mouse lymphocyte surface receptor for HEV. These findings demonstrate that the molecule defined by Hermes-1 either functions as a specific lymphocyte surface receptor for HEV, or is both precisely coregulated and physically and/or functionally associated with such receptors. The expression of this putative receptor for HEV on normal human lymphocyte populations parallels, and thus presumably helps determine, their migratory status in vivo. Hermes-1 should be a powerful tool for analyzing the role of endothelial cell recognition in the traffic of normal and neoplastic human lymphocytes.

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The current study examines the possibility that the TCR repertoire of L3T4-, Lyt-2- cells in lpr/lpr mice is enriched for self-reactive specificities. T cells utilizing V beta 17a and V beta 8.1 gene products have been shown to be clonally eliminated in nonautoimmune mice expressing I-Ek and Mlsa/H-2k, respectively, because of their potential self reactivity. We quantitated these V beta specificities in lymph nodes and spleens of lpr/lpr mice. The results indicate that lpr-dependent L3T4-/Lyt-2- T cells, similar to normal peripheral T cells, have undergone a repertoire modification such that potential self-reactive V beta specificities have been eliminated. Evidence for tolerance in this population provides insight into the development of these aberrant cells, and may also have important implications for normal T cell development in the thymus.

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Mouse thymocytes, which are approximately 90% immature cortical cells, are low in surface sialic acid when compared with more mature cortisone-resistant, presumably medullary, thymocytes and peripheral T lymphocytes. Thus, medullary thymocytes bind and are agglutinated by the N-acetylneuraminic acid-specific lectin, lobster agglutinin 1 (LAgl), whereas cortical thymocytes are not agglutinated by this lectin. It is demonstrated herein that mouse cortical thymocytes, purified using LAgl, do not respond to the mitogenic effects of concanavalin A (Con A). The lack of response to this lectin is not due to depletion of macrophages, since addition of macrophages does not restore the response. Populations of LAgl-negative thymocytes can be made to respond weakly to Con A by the addition of interleukin 2, but this response appears to be due to the presence of a few contaminating LAg1-binding thymocytes since it is abolished by treatment of the cells with rabbit anti-LAgl serum plus complement. Therefore highly purified cortical thymocytes not only cannot respond to Con A, but also they cannot be induced to respond by the addition of the T cell growth factor, interleukin 2. Thymocytes isolated by a single criterion, that is by virtue of their low amount of surface sialic acid, appear to be a truly immature population of thymocytes.

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