Effect of female sex hormones on blastic transformation of lymphocytes in systemic lupus erythematosus and in healthy women

The susceptibility of women to autoimmune diseases is well-documented, of which systemic lupus erythematosus (SLE) is especially important. The use of oral contraceptives often activate SLE from a quiescent condition. The inductive effect of estrogen has been shown in animal studies indicating that female hormones can trigger autoimmune reaction. The effect of ethinyl estradiol, an estrogen (E), and d-norgestrel, a progesterone (P), on the mitogenic response of peripheral lymphocytes, and particularly on phytohemagglutinin (PHA)- and concanavalin-A (Con-A)-induced blastic transformation of lymphocytes (LBT) was studied in vitro. 25 patients with SLE and 27 healthy controls participated in the study. SLE was inactive in 16 patients, 7 took corticosteroids, and 3 also received 50 mg/day Imuran. 13 patients and 10 controls took contraceptives (Bisecurin, Infecundin, Ovidon, Rigevidon). The LBT value fell significantly in patients with active SLE, in contraceptive users, and the value was significantly lower in inactive patients than in those not using contraceptives. E and P separately or together significantly reduced LBT values. Contraceptives containing P only can be prescribed for women suffering from SLE, as its role in inducing the disease compared to E is negligible.     

Immunomodulator effect of silymarin therapy in chronic alcoholic liver diseases

The effects of the hepatoprotective, antioxidant drug silymarin (Legalon) on some cellular immune parameters of patients with histologically proven chronic alcoholic liver disease were studied in a six month double blind study. The lectin induced proliferative activity of the lymphocytes got enhanced, the originally low T cell percentage and the originally high CD8+ cell percentage have been normalized, the antibody-dependent and natural cytotoxicity of the lymphocytes decreased during silymarin therapy. All these changes were significant, while in the placebo group no significant changes occurred, except for a moderate elevation of the T cell percentage. Thus, the immunomodulatory activity of silymarin might be involved in the hepatoprotective action of the drug and improves the depressed immunoreactivity of the patients.     

Stimulation of lectin-dependent cell-mediated cytotoxicity against adherent HEp-2 cells by carrageenan

The effect of carrageenan (CGN) was studied on lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. Cytotoxicity was measured by detachment from the monolayer of 3H-TdR pre-labelled HEp-2 cells. LDCC was evaluated in a 24 h assay at 50:1 effector-target cell ratio in the presence of 25 micrograms/ml concanavalin A (Con A). Under these conditions but without Con A considerable cytotoxicity was not elicited by peripheral blood mononuclear cells (PBMC). Addition of CGN to the system significantly increased LDCC to HEp-2 targets. Monocyte depletion of effector cells had no major influence to the effect of CGN on LDCC activity. In parallel studies CGN also enhanced the Con A-induced proliferation of PBMC.     

Lectin-dependent cell-mediated cytotoxicity and blastogenesis by large granular-enriched and depleted lymphocytes.

The role of larger granular-enriched and depleted lymphocytes was studied in lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. LDCC was evaluated by detachment from the monolayer of 3H-thymidine-prelabelled HEp-2 cells in a 24 h assay at effector-target cell ratios of 25:1 and 50:1 in the presence of 25 micrograms/ml concanavalin A (Con A). Under the aforementioned conditions but in the absence of Con A natural cell-mediated cytotoxicity (NCMC) was not found. However, cytotoxicity was significantly augmented in the presence of Con A (= LDCC) using human peripheral blood mononuclear cells (PBMC) as effectors. Large granular lymphocytes (LGL), which show high natural killer (NK) activity to K 562 target cells, failed to be cytotoxic against HEp-2 targets similar to large granular depleted lymphocytes (LGL-DL). On the other hand, LGL caused only a slight LDCC; whilst LGL-DL induced strong LDCC activity towards HEp-2 targets. In comparison to LDCC using LGL-DL as effector cells, LGL and LGL-DL mixed at a ratio of 1:2, and added to target cells, had no major effect on LDCC, while a lower level of LDCC was observed at LGL/LGL-DL ratios of 1:1, and 2:1, suggesting the dilution of LGL-DL, potential effectors of LDCC to HEp-2 cells, rather than a specific regulatory role of LGL in LDCC. In parallel studies, the proliferation of LGL-DL in response to Con A was less than that observed with PBMC or LGL. The response could be restored by replacing half of LGL-DL per culture with an equal number of LGL, or by the addition of 10% monocytes. Significant functional differences between LGL and LGL-DL in LDCC as well as in Con A-induced blastogenesis are suggested.     

Depressed Natural and Lectin-Dependent Cell-Mediated Cytotoxicity Against Adherent Hep-2 Cells in Patients with Systemic Lupus Erythematosus

Natural cell-mediated cytotoxicity /NCMC/ was evaluated using human adherent 3H-thymidine-prelabelled HEp-2 epipharynx carcinoma cells as targets at 50:1 effector-target cell ratio in a 24 hr assay. For lectin-dependent cell-mediated cytotoxicity /LDCC/ studies cultures contained also 25/Ug/ml concanavalin A /Con A/. Peripheral blood mononuclear cells /PBMC/ of nine patients with active systemic lupus erythematosus /SLE/ failed to exert NCMC or LDCC against HEp-2 targets. In contrast, an increased adherence /decreased detachment from the monolayer/ of HEp-2 target cells was observed in the presence of PBM3 from SLE patients that was further promoted by the addition of Con A during LDCC assay.     

Depressed effector activity of OKT4+ and OKT8+ T cell subsets in lectin-dependent cell-mediated cytotoxicity to HEP-2 cells in patients with systemic lupus erythematosus

The role of OKT4+ and OKT8+ T cell subsets was studied in depressed lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 target cells by peripheral blood mononuclear cells (PBMC) from patients with active systemic lupus erythematosus (SLE). LDCC activity was evaluated by detachment from the monolayer of 3H-TdR-prelabelled HEp-2 cells in a 24 hr assay at 50:1 effector-target cell ratio in the presence of 25 micrograms/ml concanavalin A (Con A). Decreased levels of LDCC were performed by all studied effector cell populations of SLE patients, including both OKT4+ and OKT8+ T cell fractions. LDCC by isolated OKT8+ T cells was superior to that by OKT4+ and unfractionated T lymphocytes from all healthy and SLE subjects. This suggests that the defect of LDCC activity in SLE did not affect the inherently higher LDCC effector activity of OKT8+ to OKT4+ cells. In parallel studies a reduced proliferation of PBMC in response to Con A and failure of OKT8+ T cells to suppress Con A-induced blastogenesis was observed in patients with SLE.     

Indomethacin abrogates the suppression by cyclosporin A of lectin-dependent cell-mediated cytotoxicity to HEp-2 cells

The effects of cyclosporin A, prostaglandin E1 and indomethacin were studied on lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. LDCC activity by human peripheral blood lymphocytes was evaluated by detachment from the monolayer of [3H]thymidine-prelabelled HEp-2 cells in a 24-h assay at 50:1 effector:target cell ratio in the presence of 25 micrograms/ml concanavalin A. Under these conditions, but without concanavalin A, considerable natural cell-mediated cytotoxicity was not elicited although LDCC was significantly augmented in the presence of concanavalin A. Addition of both cyclosporin A (0.1, 1.0 or 10 micrograms/ml) and prostaglandin E1 (10(-8), 10(-7) or 10(-6) M) dose-dependently suppressed LDCC activity. Indomethacin (0.1, 1.0 or 10 micrograms/ml) did not in itself influence LDCC although suppression of LDCC by cyclosporin A, but not prostaglandin E1, was abrogated in the presence of indomethacin. Similar to indomethacin, acetyl salicylic acid also reversed the inhibition of LDCC by cyclosporin A. In parallel experiments, cyclosporin A elicited a more than two-fold increase of prostaglandin E production under LDCC assay conditions as measured by radioimmunoassay. Contrary to LDCC, depression of concanavalin A induced blastogenesis by cyclosporin A was not influenced by indomethacin, suggesting that the inhibition by cyclosporin A of LDCC and concanavalin A-induced blastogenesis proceed via different mechanisms.     

Stimulation by thymopoietin oligopeptides of lectin-dependent cell-mediated cytotoxicity in patients with systemic lupus erythematosus

The effect of thymopoietin penta- (TP-5), tetra-(TP-4), and tripeptides (TP-3) was studied on the depressed lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 target cells by peripheral blood mononuclear cells from patients with active systemic lupus erythematosus (SLE). LDCC activity was evaluated by detachment from the monolayer of 3H-thymidine-prelabelled HEp-2 cells in the presence of concanavalin A (Con A). While 10(-5)M TP-3 moderated the depression, 10(-5) M TP-5 strongly enhanced LDCC activity in SLE patients up to the normal level. On the other hand, LDCC activity by normal donors was not influenced by TP-3 and TP-5. TP-4 had no major effect either in control or in SLE patients. In parallel experiments none of the thymopoietin peptides affected the Con A-induced suppressor activity on the blastogenesis of lymphocytes. A selective immunostimulatory effect of TP-3 and TP-5 on the generation of LDCC effector cells in patients with SLE is suggested.     

Effect of Fc receptor blocking on human natural and lectin-dependent cell-mediated cytotoxicity against adherent HEp-2 cells

The effect of Fc receptor (FcR) blocking by aggregated human gamma-globulin (AGG) was studied on natural (NCMC) and lectin-dependent cell-mediated cytotoxicity (LDCC) against adherent HEp-2 human epipharynx carcinoma target cells. Cytotoxicity was measured by detachment from the monolayer of [³H]TdR-prelabelled HEp-2 cells. LDCC was evaluated in a 24 h assay at 50:1 effector-target cell ratio in the presence of 25 μg/ml concanavalin A (Con A). Under these conditions but without Con A considerable NCMC was not elicited by normal lymphocytes. FcR blocking by AGG treatment of effector cells resulted in a significant NCMC activity to HEp-2 targets. In contrast, AGG treatment profoundly depressed LDCC. Monocyte depletion of effector cells had no major influence on the effect of AGG on NCMC and LDCC activities. An interference of FcR blocking by AGG and LDCC in response to Con A is suggested.