Thy-1-specific helper T cells can provide intramolecular help, but can provide intermolecular help only if the phosphatidylinositol anchor of Thy-1 is replaced by a membrane insert

Peripheral T-cell lymphomas. Immunoregulatory cytokine (interleukin-2, interleukin-4, and interferon-gamma) abnormalities and autologous mixed lymphocyte reaction

BACKGROUND

Cytokines are the most important secretions of the immune system and have a wide range of immunoregulatory functions in various immune disorders and T-cell malignancy. The authors have determined that characteristic enhanced autologous mixed lymphocyte reaction (AMLR) of the lymph node-derived malignant T-cells from peripheral T-cell lymphomas is a function of the T-cell derived cytokines interleukin (IL)-2, IL-4, and interferon-gamma (IFN-tau).

METHODS

Autologous mixed lymphocyte reaction assay was performed by the standard proliferative response (3H-thymidine incorporation), by culturing autologous lymph node-derived or blood-purified T-cells with autologous blood-purified mitomycin-c treated non-T-cells. The production of IL-2, IL-4, and IFN-tau in the AMLR cultures was determined by bioassay or enzyme immunoassays.

RESULTS

Enhanced IL-2 and IFN-tau but deficient IL-4 production is the most characteristic and unique feature of the augmented AMLR in peripheral T-cell lymphomas.

CONCLUSION

The immunoregulatory aberrations in lymph node-derived malignant T-cells that produce highly elevated IL-2 and IFN-tau but decreased IL-4 during augmented AMLR may play an important role in immune dysfunction in this neoplasm (peripheral T-cell lymphomas).

Memory in helper T cells of minor histocompatibility antigens, revealedin vivo by alloimmunizations in combination with Thy-1 antigen

A cooperative antibody response in which T helper (Th) cells recognize minor histocompatibility antigens (mha) and B cells recognize Thy-1 antigen, is used to explore memory in the T cell compartment. In contrast to B cell memory, Th memory reaches a plateau rapidly, although Th memory of Thy-1 itself (or an associated antigen) behaves exceptionally in this respect. The plateau then extends over several weeks at least. Single mha, among them H-Y, generate detectable memory. Incompatible H-2 antigens, including class I antigens on their own, inhibit this response through what appears to be a mechanism of intracellular antigenic competition. Antigen presentation in this system is by host cells, as judged by lack of donor-specific restriction. Memory resides in both the CD45RA+ and CD45RA- compartments, although the majority of memory Th cells have the latter phenotype.

The "adjuvant effect" of the polymorphic B-G antigens of the chicken major histocompatibility complex analyzed using purified molecules incorporated in liposomes

The polymorphic B-G region of the chicken major histocompatibility complex has previously been shown to mediate an "adjuvant effect" on the humoral response to other erythrocyte alloantigens. We demonstrate here that B-G molecules purified with monoclonal antibodies exert this adjuvant effect on the production of alloantibodies to chicken class I (B-F) molecules, when the two are in the same liposome. The adjuvant effect may in part be mediated by antibodies, since the antibody response to B-G molecules occurs much faster than the response to B-F molecules, and conditions in which antibodies to B-G are present increase the speed of the response to B-F molecules. We also found that the presence of B-G molecules in separate liposomes results in a lack of response to B-F molecules. In the light of this and other data, we consider the possible roles for the polymorphic B-G molecules, particularly for the generation of B cell diversity, in the immune systems of birds and other animals.

Dominant reduced responsiveness controlled by H-2(Kb)Ab. A new pattern evoked by Thy-1 antigen and F liver antigen

In the most frequently used panel of H-2 recombinant strains, B10.A, B10.A(4R), B10.A(5R), and B10, inhibition of the immune response has hitherto mapped to H-2E. Inhibition of the responses to Thy-1 antigen and to F liver protein, as described here, maps in a novel pattern to H-2KbAb, and presumably to H-2Ab. Enhancement of the adoptively transferred anti-Thy-1 response by treatment with CD8-specific antibody suggests, very provisionally, that T cells with suppressive activity mediate the inhibition. The evolution of this new pattern, and of dominant reduced responsiveness in general, is discussed and its relevance to immunological diseases assessed. An enzyme-linked immunosorbent assay (ELISA) for F-specific antibodies is introduced.