Differences in sensitivity to melphalan between con A-activated and nonactivated human T-cell subsets

Effect of a garlic derivative (alliin) on peripheral blood cell immune responses

The in vitro effect of the garlic derivative alliin, on the mitogen induced peripheral blood mononuclear cell (PBMC) proliferation and cytokine production was examined. In addition, its effect on the engulfing capacity of phagocyting cells was evaluated. The results showed an increase in pokeweed mitogen (PWM) induced cell proliferation, IL-1beta and TNF-alpha production, as well as in the engulfing capacity of both percentage of phagocyting cells and number of latex particles phagocytized by each individual cell. The Con-A induced cell proliferation and IL-6 production decreased following incubation with alliin, whereas PHA-induced cell proliferation, IL-2 and superoxide anion generation remained unchanged. It is concluded that alliin in vitro exerts an immunomodulatory effect on certain functions of the peripheral blood cells.

Therapeutic effectiveness against MOPC-315 plasmacytoma of low or high doses of the synthetic thymic hormone THF-gamma 2 in combination with an "immunomodulating" or a "non-immunomodulating" drug

We reported previously that treatment of mice bearing MOPC-315 plasmacytoma with the drugs L-PAM (phenylalanine mustard) or 5-FU (5-fluorouracil), in combination with low doses of THF-gamma 2, was more effective in increasing their survival time than treatment with the drug alone. We show here that in the combined treatment using a single injection of 5-FU followed by multiple (8-15) injections of THF-gamma 2, the megadoses were more effective than the low doses in increasing the survival time of MOPC-315 tumor-bearing mice. On the other hand, in combination with L-PAM, both low and high doses of THF-gamma 2 were equally effective. The need for high doses of THF-gamma 2, when used in combination with 5-FU, could be due to the fact that 5-FU acts as a "non-immunomodulating" drug and has to be used at a high, immunosuppressive dose.

B lymphocyte function in multiple myeloma: analysis of T cell- and monocyte-dependent antibody production

T-cell and B-cell functions were studied in 35 patients with untreated multiple myeloma (MM) and in 16 patients with MM treated with prednisolone, melphalan and vincristine. The numbers of CD4+ T cells were normal in untreated MM patients, but markedly decreased in treated patients, whereas CD8+ cell numbers were normal in untreated and treated patients. Mitogen-induced as well as antigen-induced lymphocyte proliferative responses were reduced, but not further affected by treatment. The antigen-induced proliferative responses by lymphocytes of treated, but not of untreated patients, correlated positively to the proportions of CD4+ cells among MNC. Taken together, the findings suggest selective loss of CD4+ subpopulations during cytotoxic treatment. Pokeweed mitogen (PWM)-induced Ig production was generally low, but significantly reduced Ig production was only seen in experiments employing MM B cells and monocytes co-cultured with irradiated T-enriched cells. Irradiated MM T cells displayed normal helper function when co-cultured with normal B cells stimulated with PWM. MM B cells and monocytes cultured with irradiated normal T cells produced little Ig; however, MM monocytes were not suppressive. In 2 of 3 patients with either IgG-kappa or IgA-kappa myeloma, the numbers of PWM-stimulated B cells that produced kappa chains were somewhat higher than those found among normal MNC. The impaired ability of antibody production by B cells from untreated MM patients seems to relate to intrinsic B cell defect(s) rather than to abnormal regulation by T cells or monocytes. However, disturbances in the functions of CD4+ cells may be observed in treated MM.