Tailored antihypertensive drug therapy prescribed to older women attenuates circulating levels of interleukin-6 and tumor necrosis factor-α

Juliana O Toledo,1 Clayton F Moraes,2,3 Vinícius C Souza,2 Audrey C Tonet-Furioso,2 Luís CC Afonso,4 Cláudio Córdova,3 Otávio T Nóbrega1,2 1Graduate Program in Health Sciences, 2Graduate Program in Medical Sciences, University of Brasília, Brasília, 3Graduate Program in Gerontology, Catholic University of Brasília, Brasília, 4Research Center in Biological Sciences, Federal University of Ouro Preto, Ouro Preto, Brazil Objective: To test the hypothesis that antihypertensive drug therapy produces anti-inflammatory effects in clinical practice, this study investigated circulating levels of selected proinflammatory mediators (interleukin-6 [IL-6], tumor necrosis factor-alpha [TNF-α], and interferon-γ [INF-γ]) in response to multivariate drug directions for blood pressure (BP) control.Methods: Prospective study involving 110 hypertensive, community-dwelling older women with different metabolic disorders. A short-term BP-lowering drug therapy was conducted according to current Brazilian guidelines on hypertension, and basal cytokine levels were measured before and after intervention.Results: Interventions were found to represent current hypertension-management practices in Brazil and corresponded to a significant reduction in systolic and diastolic BP levels in a whole-group analysis, as well as when users and nonusers of the most common therapeutic classes were considered separately. Considering all patients, mean IL-6 and TNF-α levels showed a significant decrease in circulating concentrations (P<0.01) at the endpoint compared with baseline, whereas the mean INF-γ level was not significantly different from baseline values. In separate analyses, only users of antagonists of the renin–angiotensin system and users of diuretics exhibited the same significant treatment-induced reduction in serum IL-6 and TNF-α observed in the whole group.Conclusion: Our data demonstrates that a clinically guided antihypertensive treatment is effective in reversing the low-grade proinflammatory state of serum cytokines found in postmenopausal women and support extracardiac benefits from diuretics and renin–angiotensin system antagonists. Keywords: renin–angiotensin system, cytokine, hypertension, drug therapy, guidelines, inflammation&nbsp

The debate over the effector function of eosinophils in helminth infection: new evidence from studies on the regulation of vaccine immunity by IL-12

The production of Th1-type cytokines is associated with strong cell-mediated immunity while Th2-type cytokines are typically involved in the generation of humoral immune responses. In mice vaccinated a single time (1X) with attenuated cercariae of Schistosoma mansoni, the immunity induced is highly dependent on CD4+ T cells and IFN-gamma. In contrast, mice vaccinated multiple times (3X) have decreased IFN-gamma expression, develop a more dominant Th2-type cytokine response as well as protective antibodies which can passively transfer immunity to naive recipients. Previously, we demonstrated the ability of IL-12, a potent IFN-gamma-inducing cytokine to enhance (1X) schistosome cell-mediated immunity when administered during the period of immunization. More recently, we asked what effects IL-12 would have on the development humoral-based immunity. While multiply-immunized/saline-treated mice demonstrated a 70-80% reduction in parasite burden, 3X/IL-12-vaccinated animals displayed an even more striking >90% reduction in challenge infection, with many mice in the later group demonstrating complete protection. Analysis of pulmonary cytokine mRNA responses demonstrated that control challenged mice elicited a dominant Th2-type response, 3X/saline-vaccinated produced a mixed Th1/Th2-type cytokine response, while 3X/IL-12-immunized animals displayed a dominant Th1-type response. The IL-12-treated group also showed a marked reduction in total serum IgE and tissue eosinophilia while SWAP-specific IgG2a and IgG2b Abs were elevated. Interestingly, animals vaccinated with IL-12 also showed a highly significant increase in total Ig titers specific for IrV-5, a known protective antigen. More importantly, 3X/IL-12 serum alone, when transferred to naive mice reduced worm burdens by over 60% while 3X/saline serum transferred significantly less protection. Nevertheless, animals vaccinated in the presence of IL-12 also develop macrophages with enhanced nitric oxide dependent killing activity against the parasites. Together, these observations suggest that IL-12, initially described as an adjuvant for cell-mediated immunity, may also be used as an adjuvant for promoting both humoral and cell-mediated protective responses

The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis

Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.<br>A Leishmania amazonensis é o principal agente etiológico da leishmaniose cutânea difusa, uma doença associada a respostas imunes anérgicas. Neste estudo nós mostramos que o extrato bruto de promastigotas de Leishmania amazonensis (LaAg), mas não de L. braziliensis (LbAg), contém substâncias que suprimem respostas proliferativas, espontâneas e mitogênicas, de células T. As substâncias supressoras no LaAg são termo-resistentes (100°C/1h) e parcialmente dependentes da atividade de proteases. A anergia de células T não foi devida à diminuição na produção de fatores de crescimento, uma vez que não foi revertida pela adição de: IL-2, IL-4, IFN-gama ou IL-12. O LaAg não inibiu a ativação de células T induzida por anti-CD3, sugerindo que a anergia é devida a um defeito na apresentação de antígenos. A anergia não foi devida à necrose celular, mas foi acompanhada de uma expressiva fragmentação de DNA nas células de linfonodos, indicativo de apoptose. Apesar da pré-incubação de macrófagos com LaAg ter inibido sua capacidade de apresentação de antigenos, este efeito não foi devido à apoptose dos primeiros. Estes resultados sugerem que a anergia de células T encontrada na leishmaniose difusa deve ser devida à apoptose dessas células que se segue à apresentação defeituosa de antígenos pelo antígeno do parasito