Endogenous estrogens have significant immunomodulatory effects characterized as suppression of cell mediated immunity and stimulation of humoral immunity. Xenoestrogens are environmental estrogens that have endocrine impact, acting as estrogen agonists and antagonists but whose immune effects are not well characterized. Using CD4⁺ Jurkat T cells as a model, the effects of representative xenoestrogens on T proliferation, cell cycle, and apoptosis were examined. Coumestrol (CM), a phytoestrogen, and tetrachlorodioxin (TCDD) in concentrations of 10^-4 to 10^-6M significantly inhibited Jurkat T cell lymphoproliferation, whereas bisphenol A (BPA) and DDT had minimal effect, but did antagonize 17-β-estrtadiol induced effects. Xenoestrogens, especially CM, produced accumulation of Jurkat T cells in G₂/M phase, and subsequently induced apoptosis, particularly CM (% apoptotic cells = 30 ± 12 vs. control = 5 ± 2). These changes were associated with DNA fragmentation. BPA and DDT also induced DNA fragmentation but not significant DNA hypoploidy. Xenoestrogen – CM, BPA, DDT, and TCDD - exposure suppressed bcl-2 protein and mRNA transcript levels but augmented p53 protein and mRNA transcripts. Human purified peripheral blood lymphocytes responded with similar significant cell cycle changes (G₀/G₁ exodus and G₂/M accumulation) for CM, BPA, and DDT exposure. These preliminary data, taken together, suggest that xenoestrogens have direct, compound-specific T lymphocyte effects that enhance our understanding of environmental modulation of immune and autoimmune responses. Full article

Ion transport enzymes may play an important role in T cell activation. This study investigates the role of turmeric and its individual components, turmerin-and curcumin-on Ca²⁺ and Na/K⁺ adenosine triphosphatases (ATPase) in the course of T cell activation. Concanavalin A (Con A) stimulated human blood mononuclear T cell proliferation paradigm was investigated for 3, 5 and 7 day periods with different concentrations of turmeric, curcumin and turmerin. Con A-stimulated cells treated with turmeric (250, 50, 5 μg/ml) for 3 and 5 days inhibited ATPase levels when compared to base levels obtained by cells in media alone. At day 7, there was a 3-fold increase for Ca²⁺ATPase levels and a 2-fold increase for Na/K⁺ATPase. Curcumin (250, 50, 5 μg/ml) showed the same pattern for ATPase activity as turmeric at 3 and 5 days with a 2-fold increase at day 7. Turmerin (2500, 1250, 250, 25 ng/ml) for Na/K⁺ ATPase activity showed an increase at day 3, a decrease on day 5, and a 2-fold increase on day 7. Ca²⁺ ATPase activity in the presence of turmerin showed an increase in ATPase levels at day 3 (except at 2500ng/ml where it decreased) and a decrease in day 5 (except at 25 ng/ml where it increased). Turmeric and curcumin generally inhibited Ca²⁺ATPase and Na/K+ATPases in early (day 3) and intermediate (day 5) stages of mitogen stimulation. However, the effect after 7 days incubation for turmeric, curcumin and turmerin showed a marked increase up to three fold. Full article

Oxidative stress is implicated in HIV-infection. It has been suggested that plant antioxidants may offer protection from viral replication and cell death associated with oxidative stress in patients with HIV/AIDS. Because of inherent antioxidant properties of turmeric (T) and its derivatives, water-soluble extract turmerin (Tm) and lipid soluble curcumin (Cu), their potential efficacy as anti-HIV drugs were examined. Cell viability and p-24 antigen release by CEMss-T cells (1 x 10⁵ cells/ml) infected with HIV-III_B strain, used as an acute model of infection, were tested in the presence of 3’azido-3’deoxythmidine (AZT). Proliferative responses of human mononuclear cells derived from HIV patients (chronic model) stimulated with phyohemagglutinin (PHA), concanavalin A (ConA), and pokeweed mitogen (PWM) were also examined in the presence of AZT and Tm. In the infection assay, T, Tm and Cu individually did not reduce p-24 antigen release or improve cell viability. AZT (5μM) + Tm (800 ng/ml) inhibited infection by 37 % and increased cell numbers by 30%; whereas, Tm (80 ng/ml) inhibited infection by 26% and increased cell number by 60%. In the proliferation assay, lymphocytes from HIV-infected patients showed better inhibition of mitogen responsiveness to Tm (800 ng/ml) when compared to AZT at 5 μM or Tm at 80 ng/ml. Turmerin inhibited HIV-infected T-cell proliferation and, in combination with AZT, decreased T-cell infection and increased cell viability. These data provide evidence suggesting that efficacious anti-HIV therapy may be possible using lower, less toxic doses of AZT in the presence of turmerin. Full article