IL-1 and PGE2 productions by the regional lymph node cells from DNFB-sensitized mice.

Interleukin 1 (IL-1) and Prostaglandin E2 (PGE2) are mainly produced by macrophage/monocytes. In this experiment, we investigated the immunological role of macrophage/monocytes in the lymph nodes (LNs) by measuring IL-1 and PGE2 productions of regional LN cells from dinitrofluorobenzene (DNFB)-sensitized and -tolerant mice. LN cells from sensitized mice produced IL-1 in remarkable amounts after in vitro antigen stimulation. On the other hand, the LN cells from tolerant mice failed to produce IL-1 or PGE2. These data indicate that, by modifying cytokine production, macrophage/monocytes in the regional LNs play a key role in the pathomechanism of contact hypersensitivity.

[An immune adjuvant activity of mycolic acid-containing glycolipid, trehalose-2,3,6'-trimycolate, derived from Gordona aurantiaca].

A mycolic acid-containing glycolipid, trehalose-2,3,6'-trimycolate (GaGM), derived from Gordona aurantiaca, an acid-fast bacterium closely related taxonomically to Mycobacterium, was investigated for its immune adjuvant activity on cell-mediated responses in the mouse. I.V. injection of liposomes containing GaGM enhanced the generation of cytotoxic T-lymphocyte (CTL) against syngeneic and allogeneic tumor cells. In addition, the injection of GaGM augmented the natural killer (NK) activity and the antibody-dependent cellular cytotoxicity (ADCC). These results suggest that the injection of GaGM induces the production of interleukin-2 (IL-2), since such effector cells as CTL, NK and K cells have been shown to require IL-2 for their development.

In vivo generation of tumor-specific cytotoxic T-cells in the regional lymph node: effect of subcutaneous inoculation of mls-disparate spleen cells around implanted tumors in mice.

Generation of immunological resistance to a B-cell tumor was attempted by inoculating histoincompatible spleen cells around the sites of implanted tumor cells. Syngeneic hybridomas developed in the regional area of 96% of the control mice but in 4% of the mice that had received s.c. inoculation of H-2-matched, mls-disparate spleen cells. The regional lymph node cells of the mice in which tumors did not develop showed direct cytotoxicity against the hybridoma cells. This cytotoxicity was sensitive to treatment with the monoclonal anti-Thy-1.2 and complement and was specific for the tumor cells. After s.c. inoculation of mls-disparate spleen cells, cells of the regional lymph node were shown to produce interleukin 2. Primary cultures of the recipient lymph node cells and the donor spleen cells in the presence of T-cell growth factors showed that the tumor-specific cytotoxic T-lymphocytes were derived from the donor spleen cells. These results strongly suggest that on injection of mls antigen-disparate spleen cells, injected splenic T-cells specific for the tumor developed into functional cytotoxic T-lymphocytes with the help of interleukin 2 which was produced by the mixed lymphocyte reaction in vivo and thus prevented tumor growth. The possibility of clinical application of this procedure in the immunotherapy of neoplasms is discussed.

Successful generation of cytotoxic T lymphocytes specific for self immunoglobulin-determinants on B lymphocytes.

Cytotoxic T lymphocytes (CTL) specific for self immunoglobulin (Ig) determinants on B lymphocytes were successfully generated. These CTL were induced with stimulator B hybridoma cells bearing self Ig determinants in responders compatible with the stimulators in H-2 antigens but disparate in minor H antigens. Their specificities were directed toward the idiotype and probably the allotype structures of Ig receptors on stimulator B cells. However, no CTL specific for Ig structures other than the idiotype and the allotype were detected. These data indicate the presence of specific precursor CTL for self B cell clones and suggest the possible development and function of these CTL in certain situations.