Interaction of macrophages and lymphocytes for lymphokine production and cellular proliferation

Desensitization. V: Suppression of MIF production by lymphokine-activated macrophages

The systemic injection of high doses of antigen into a previously immunized animal results in a state of transient anergy with respect to cell-mediated immune reactions. This phenomenon is known as desensitization. We have previously shown that desensitization is a multistage process. The initial 24-hr period is characterized by excessive lymphokine production with a failure to express delayed hypersensitivity reactions due to abolition of local chemotactic gradients. Subsequent stages of desensitization involve failure of lymphokine production in vivo. The results presented here demonstrate that lymphocytes obtained from immunized and desensitized animals later than 24 hr after desensitization are markedly suppressed in their ability to produce MIF. In addition, it was found that lymphokine-activated macrophages can suppress in vitro MIF production by lymphocytes from immune, nondesensitized animals. In vitro and in vivo activation of macrophages were equally effective. Thus, it is likely that at least one mechanism for the inhibition of lymphokine production in the post-24-hr period of desensitization, involves activation of a population of suppressor macrophages by lymphokines produced during the initial 24-hr period.

Mononuclear-cell subsets in human idiopathic crescentic glomerulonephritis (ICGN): analysis in tissue sections with monoclonal antibodies

Mononuclear inflammatory cells (MIC) were analyzed in renal biopsies from 16 patients with ICGN (7 with glomerular immune complex deposits, 3 with anti-GBM disease, and 6 without immune deposits) by the avidin-biotin-immunoperoxidase technique utilizing monoclonal antibodies to cell surface antigens: T11 (total T), T4 (inducer/helper T), T8 (suppressor/cytotoxic T), B1 (B cells), M1 (monocytes/granulocytes), and Leu 7 [natural killer (NK) cells]. Total MIC were significantly increased in both glomeruli and interstitial tissues of the patients. Interstitial MIC consisted mainly of lymphocytes (80%) and monocytes (19%), with small numbers of B and NK cells present. In contrast, MIC in renal glomeruli of patients with ICGN were composed of monocytes (65%) rather than T lymphocytes (34%). A majority of T lymphocytes found in renal tissues of patients and controls had the helper/inducer phenotype. Tissue T4/T8 ratios were not significantly different in the glomeruli and interstitium. Monocytes and T lymphocytes accumulating in renal tissues of patients with ICGN may mediate glomerular injury in all forms of human ICGN.

Effects of indomethacin on lymphocyte proliferation, suppressor cell function, and leukocyte migration inhibitory factor (lmif) production

The in vitro effect of indomethacin (IND) on PHA- and Con-A-induced immune responses was studied. The results showed that the enhancement of both PHA and Con A responses by IND does not significantly depend on the concentrations of mitogens or IND. A significant negative correlation was found between the initial PHA response and augmentation index, whereas there was a positive correlation between the initial Con A response and the enhancement of the Con A responses. Indomethacin significantly increased the Con-A-induced suppressor cell activity and PHA-induced leukocyte migration inhibitory factor production (LMIF), whereas the effects on the PHA-induced suppressor cell activity and Con-A-induced LMIF production were not significant. The findings indicate the indomethacin has a dual effect on PHA- and Con-A-induced immune responses probably reflecting intrinsic differences among T cells, for example, distinct lymphokines produced by different T-cell subpopulations.