Alexandre dos Santos Pyrrho

CCL2/MCP-1 controls parasite burden, cell infiltration, and mononuclear activation during acute Trypanosoma cruzi infection

CCL2/MCP‐1 has emerged recently as a critical factor in infectious and autoimmune myocarditis. In fact, this chemokine is produced in great amounts in hearts from Trypanosoma cruzi‐infected mice and is known to enhance parasite uptake and destruction by macrophages. Herein, we studied the involvement of CCL2 in tissue inflammation and resistance to T. cruzi. Infected CCL2−/− mice developed higher parasitemias and died earlier than WT mice. Close to their death, T. cruzi‐infected CCL2−/− presented greater amounts of TNF, IFN‐γ, and IL‐10 in plasma than WTs and clinical signs of systemic inflammatory response. Amastigote nests were more frequent in hearts and livers from infected CCL2−/− tissues than in WTs, and reduced numbers of leukocytes infiltrated their tissues. Leukocytes formed diffuse but not focal infiltrates in hearts from infected CCL2−/− mice, and perivascular cuffs could still be found in their livers. Infected CCL2−/− mice had smaller percentages of activated CD11b (Mac‐1)+CD107b (Mac‐3)+ macrophages and CD8+CD69hi cells among heart and liver infiltrates than WTs (flow cytometry), indicating that CCL2 controls subset migration/activation. CCL2 accumulated among focal heart infiltrates, suggesting that this chemokine is involved in retention of mononuclear cells in particular spots. Peritoneal macrophages from CCL2−/− mice displayed decreased trypanocidal activity. Our results demonstrate that CCL2 contributes to reduce parasite growth and indicate that it does so by controlling the distribution, cellular composition, and state of activation of inflammatory infiltrates in acute T. cruzi infection.

In vitro and in vivo studies into the biological activities of 1,10-phenanthroline, 1,10-phenanthroline-5,6-dione and its copper(II) and silver(I) complexes

1,10-Phenanthroline (phen, 5), 1,10-phenanthroline-5,6-dione (phendione, 6), [Cu(phendione)3](ClO4)2·4H2O (12) and [Ag(phendione)2]ClO4 (13) are highly active, in vitro, against a range of normal and cancerous mammalian cells, fungal and insect cell lines, with the metal complexes offering a clear enhancement in activity. Cytoselectivity was not observed between the tumorigenic and non-tumorigenic mammalian lines. In in vivo tests, using Galleria mellonella and Swiss mice, all four compounds were well tolerated in comparison to the clinical agent, cisplatin. In addition, blood samples taken from the Swiss mice showed that the levels of the hepatic enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), remained unaffected. Immunocompromised nude mice showed a much lower tolerance to 13 and, subsequently, when these mice were implanted with Hep-G2 (hepatic) and HCT-8 (colon) human-derived tumors, there was no influence on tumor growth.

Macrophage migration inhibitory factor is critical to interleukin-5-driven eosinophilopoiesis and tissue eosinophilia triggered by Schistosoma mansoni infection

Macrophage migration inhibitory factor (MIF) participates in the pathogenesis of inflammatory diseases, including asthma, in which it enhances airway hypersensitivity and tissue eosinophilia. Herein, we investigated the role of MIF in eosinophilopoiesis and tissue eosinophilia using Schistosoma mansoni infection. MIF‐deficient (Mif−/−) mice had similar numbers of adult worms, eggs, and granulomas compared to wildtype mice, but the size of granulomas was strikingly reduced due to smaller numbers of eosinophils. MIF did not affect the acquired response to infection, as Mif−/− mice produced normal amounts of Th2 cytokines and IgE. Nevertheless, recombinant MIF (rMIF) behaved as a chemoattractant for eosinophils, what could partially explain the reduced eosinophilia in infected Mif−/− mice. Moreover, the percentage of eosinophils was reduced in bone marrows of Mif−/− mice chronically infected with S. mansoni compared to wild type. Mif−/− had impaired eosinophilopoiesis in response to interleukin (IL)‐5 and addition of rMIF to bone marrow cultures from IL‐5 transgenic mice enhanced the generation of eosinophils. In the absence of MIF, eosinophil precursors were unable to survive the IL‐5‐supplemented cell culture, and were ingested by macrophages. Treatment with pancaspase inhibitor z‐VAD or rMIF promoted the survival of eosinophil progenitors. Together, these results indicate that MIF participates in IL‐5‐driven maturation of eosinophils and in tissue eosinophilia associated with S. mansoni infection.—Magalhaes, E. S., Paiva, C. N., Souza, H. S. P., Pyrrho, A. S., Mourao‐Sa, D., Figueiredo, R. T., Vieira‐de‐Abreu, A., Dutra, H. S., Silveira, M. S., Gaspar‐Elsas, M. I. C., Xavier‐Elsas, P., Bozza, P. T., Bozza, M. T. Macrophage migration inhibitory factor is critical to interleukin‐5‐driven eosinophilopoiesis and tissue eosinophilia triggered by Schistosoma mansoni infection. FASEB J. 23, 1262–1271 (2009)

Unraveling the lethal synergism between Trypanosoma cruzi infection and LPS: a role for increased macrophage reactivity.

Various infections sensitize to lethal shock by promoting hyperactivation of macrophages to LPS stimulation. Although macrophages are thought to be deactivated upon contact with apoptotic cells during Trypanosoma cruzi infection, T. cruzi infection also sensitizes mice to endotoxemia. Herein, we studied the mechanisms of sensitization to endotoxemia in T. cruzi‐infected mice in order to solve the paradox. Live (but not fixed) trypomastigotes from various stocks sensitized mice to endotoxemia. Mice deficient in glycolipid recognition (TLR2–/– and CD1d–/–) were sensitized by infection to challenge with LPS. Infected mice hyperproduced TNF and IL‐10 upon LPS challenge. Infected TNF‐R1–/–, macrophage migration inhibitory factor (MIF)–/– and IFN‐γ–/– mice were lethally sensitized, but infected TNF‐R1–/– mice administered anti‐MIF survived shock with LPS. Macrophages from infected mice hyperproduced TNF in response to LPS stimulation and displayed increased expression of TLR4 compared to non‐infected controls. Treatment with the PGE2 synthesis inhibitor acetylsalicylic acid (AAS) in vivo reduced parasitemia and enhanced LPS‐stimulated production of TNF by macrophages, but the effect was less in infected mice than in normal mice. Nevertheless, AAS treatment did not increase the susceptibility of infected mice to sublethal shock with LPS. Our results point to independent MIF and TNF/TNF‐R1 lethal pathways and suggest a role for hyperactivated macrophages in T. cruzi‐sensitized LPS‐induced shock.

Layered double hydroxides intercalated with anionic surfactants/benzophenone as potential materials for sunscreens.

Layered double hydroxides intercalated with dodecylsulfate or dodecylbenzenesulfonate were synthesized by co-precipitation under alkaline conditions. After characterization by PXRD, FTIR, and TGA/DTA, the ZnxAl/SUR compounds were reacted with neutral benzophenone, using different procedures. The products obtained from benzophenone adsolubilization were investigated by PXRD, FTIR, and DRUV-Vis spectroscopy before and after exposure to UV radiation. In general, the content of adsolubilized benzophenone was small and depended on the synthetic procedure. The best results were achieved under microwave irradiation, which furnished 9.09 wt% adsolubilized benzophenone. The products presented good adsorption in the full UV region, from UVC to UVA, and good stability to UV radiation. They did not cause skin irritation in tests conducted on rabbits, which makes them good candidates for the development of a new generation of sunscreens.

Dexamethasone, a Drug for Attenuation of Schistosoma mansoni Infection Morbidity

ABSTRACT To investigate the possible use of immunomodulators as coadjuvants in the treatment of chronic schistosomiasis, the study described in the present report evaluated the effects of dexamethasone on several parameters which reflect disease severity and morbidity. Parasitological, immunological, and histological parameters were analyzed in animals treated from the first day of infection or after 35 days of infection. In both situations, dexamethasone had no effect on the parasite burden but altered the egg distribution in tissue, indicating that under the schedule used it did not interfere with the development of adult worms or oviposition. Treated mice showed a decrease in the number of eggs in hepatic tissue, reduced granuloma sizes, reduced levels of granuloma maturation, and reduced collagen contents. Dexamethasone-treated mice also had decreased gamma interferon, interleukin-12 (IL-12), and IL-4 levels in serum and increased IL-10 levels in serum. Taken together, these data suggested a decrease in the severity of murine schistosomiasis and point to dexamethasone as a convenient and promising coadjuvant agent in the therapy of this infection.

Trypanosoma cruzi : IgG1 and IgG2b are the main immunoglobulins produced by vaccinated mice

Abstract Mice vaccinated with CL-14, a non-infective and non-pathogenic clone isolated from Trypanosoma cruzi CL strain, become protected against lethal challenge by infective trypomastigotes. It has been shown that animals infected with T. cruzi show polyclonal activation of B lymphocytes with an early production of several non-specific immunoglobulins. Vaccinated mice, however, have an early production of antigen-specific IgG1 and IgG2b. Considering the lack of infectivity of CL-14, our data strongly suggest a role for IgG1 and IgG2b in protection to T. cruzi.

Silymarin Reduces Profibrogenic Cytokines and Reverses Hepatic Fibrosis in Chronic Murine Schistosomiasis

ABSTRACT In chronic schistosomiasis, hepatic fibrosis is linked to the portal hypertension that causes morbidity in Schistosoma mansoni infection. Silymarin (SIL) is a hepatoprotective and antioxidant medicament largely prescribed against liver diseases that has previously been shown to prevent fibrosis during acute murine schistosomiasis. Here we employed silymarin to try to reverse established hepatic fibrosis in chronic schistosomiasis. Silymarin or vehicle was administered to BALB/c mice every 48 h, starting on the 40th (80 days of treatment), 70th (50 days), or 110th (10 days) day postinfection (dpi). All mice were sacrificed and analyzed at 120 dpi. Treatment with silymarin reduced liver weight and granuloma sizes, reduced the increase in alanine aminotransferase and aspartate aminotransferase levels, and reduced the established hepatic fibrosis (assessed by hydroxyproline contents and picrosirius staining). Treatment with silymarin also reduced the levels of interleukin-13 (IL-13) in serum and increased the gamma interferon (IFN-γ)/IL-13 ratio. There was a linear correlation between IL-13 levels in serum and hydroxyproline hepatic content in both infected untreated and SIL-treated mice, with decreased IL-13 levels corresponding to decreased hydroxyproline hepatic contents. Treatment with either SIL or N-acetylcysteine reduced both proliferation of fibroblast cell lines and basal/IL-13-induced production of collagen I, indicating that besides inhibiting IL-13 production during infection, SIL antioxidant properties most likely contribute to inhibition of collagen production downstream of IL-13. These results show that silymarin interferes with fibrogenic cytokines, reduces established fibrosis, and inhibits downstream effects of IL-13 on fibrogenesis, indicating the drug as a safe and cheap treatment to liver fibrotic disease in schistosomiasis.

trypanosoma Cruzi Sensitizes Mice to Fulminant Seb-induced Shock: Overrelease of Inflammatory Cytokines and Independence of Chagas' Disease or Tcr Vβ-usage

Trypanosoma cruzi-infected mice display increased susceptibility to shock induced by injection of lipopolysaccharide (LPS), anti-CD3, or resulting from interleukin (IL)-10-defective response to the parasite itself, but the basis of such susceptibility remains unknown. Herein, we tested the susceptibility of mice inoculated with virulent and avirulent T. cruzi to staphylococcal enterotoxins (SE), potent inducers of inflammatory cytokine secretion. Mice infected with T. cruzi CL-strain or inoculated with the avirulent clone CL-14, a clone that does not induce disease or polyclonal lymphocyte activation, succumb suddenly to low doses of staphylococcal enterotoxin B (SEB), but not to staphylococcal enterotoxin A (SEA). High plasma levels of TNF, IFN-gamma, and liver transaminases alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were found in these mice, indicating lethal toxic shock. Sensitization to shock required inoculation of live avirulent trypomastigotes and a time interval before challenge with SEB. We found no prior skewing of T cell receptor (TCR) Vbeta-repertoire in CL-14-inoculated mice that could be responsible for sensitization. Splenocytes from CL-14-inoculated mice proliferated more under anti-Vbeta8 than anti-TCRbeta stimulation when compared with normal mice, but were suppressed to SEB stimulation. Both SEB and anti-Vbeta8 antibodies stimulated splenocytes from T. cruzi-inoculated mice to secrete higher levels of inflammatory cytokines than normal controls. Taken together, our results show that T. cruzi inoculation can sensitize mice to lethal SEB-induced shock even in the absence of tissue damage, polyclonal lymphocyte activation, or previously increased levels of inflammatory cytokines, and they suggest that altered reactivity of Vbeta8 lymphocytes may be involved in the phenomenon.

In vitro and in vivo influence of penetration enhancers in the topical application of celecoxib.

Abstract Objective: We investigated the potential effects of oleic acid (OA) and glycerol monooleate (GMO) on the skin delivery of CXB. Methods: The influence of both OA and GMO (5.0% or 10.0%) on the in vitro skin permeability of CXB (2.0%) was evaluated using propylene glycol (PG) as a vehicle. Also the in vitro potential cytotoxicity and genotoxicity and in vivo assays (skin irritation in rabbits and topical anti-inflammatory activity by in mice) were conducted. Results: As expected, the amount of CXB that permeated through the skin was minimal, but drug retention on the viable skin (epidermis plus dermis) was higher in association with treatment with 5.0% OA or GMO compared to the control treatment, meaning that there was a localized effect of CXB in the skin. No formulation presented cytotoxic or genotoxic potential, suggesting safety for cutaneous application. In vivo skin irritation assays indicated that no formulation was irritating to the skin becomes its use possible for a prolonged time. In vivo anti-inflammatory experiments indicated that both edema and protein extravasation were inhibited with a maximum % inhibition of 53.5.0% and 61.0% for 5.0 % GMO, respectively, and 48.0% and 35.5% for 5.0% OA, respectively. Such formulations were able to inhibit around twofold the percentage of ear edema in mice compared to a commercial product reference diclofenac commercial formula. Conclusion: There is no topical formulation currently available that contains both CXB and 5.0% GMO or OA, suggesting them as potential adjuvants that improve the skin delivery of CXB.