Browsing by Author "Goes, Alfredo Miranda de"

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Combined use of Paracoccidioides brasiliensis recombinant rPb27 and rPb40 antigens in an enzyme-linked immunosorbent assay for immunodiagnosis of paracoccidioidomycosis.
    (2011) Fernandes, V. C.; Coitinho, Juliana Barbosa; Veloso, Juliana Márcia Ribeiro; Araújo, Stanley de Almeida; Pedroso, Enio Roberto Pietra; Goes, Alfredo Miranda de
    Paracoccidioidomycosis (PCM) is one of themost important endemicmycoses in LatinAmerica; it's usually diagnosed by observation and/or isolation of the etiologic agent, Paracoccidioides brasiliensis, as well as by a variety of immunological methods, such as complement fixation and immunodiffusion. Although these approaches are useful, historically their sensitivity and specificity have often been compromised by the use of complex mixtures of undefined antigens. The use of combinations of purified,well-characterized antigens appears preferable andmay yield good results. In the present study combinations of the previously described 27-kDa recombinant antigen(rPb27) and a recombinant 40-kDa-molecular-mass antigen(rPb40) fromthis fungus, that was identified by Goes et al. (2005) through the AST strategy as a homolog of Neurospora crassa calcineurin B, were used in an indirect enzyme linked immunosorbent assay (ELISA) for diagnosis and follow-up of patients with PCM. The complete coding cDNA of rPb40 and rPb27 were cloned into a pET-21a and a pET-DEST 42 plasmid, respectively, expressed in E. coli with a his-tag and purified by affinity chromatography. Among 109 PCM serum samples analyzed, a homogeneous IgG response to these proteinswas observed. 62 serumsamples frompatientswith other diseases, 18 frompatientswith othermycosis and 23 fromhealthy individualswere also studied. Detection of anti-rPb27 and anti-rPb40 antibodies in sera of patientswith PCMby ELISA using a combination of the two purified proteins showed a sensitivity of 96% with a specificity of 100% in relation to control normal human sera andto sera frompatientswith other systemicmycosis and 93.5%to sera from patients with diverse infections. The use of this two proteins combination provided an excellent immunodiagnosis assaywith great values of sensitivity and specificity, even in relation to sera frompatients with othermycosis,making possible the standadization of a new methodology to diagnose this important mycosis, with a good confiability and reprodutibility.
  • No Thumbnail Available
    Item
    Down modulation of MHC surface molecules on B cells by suppressive immune complexes obtained from chronic intestinal schistosomiasis patients.
    (1998) Rezende, Simone Aparecida; Gollob, Kenneth John; Oliveira, Rodrigo Corrêa de; Goes, Alfredo Miranda de
    Granulomatous inflammation around parasite eggs is the prominent lesion in human schistosomiasis. Studies have suggested the involvement of a series of suppressive mechanisms in the control of this reaction, such as macrophages, cytokines, idiotipic interactions and immune complexes (IC). The studies examine the role of IC obtained from chronic intestinal schistosomiasis patients (ISP) in the reactivity of peripheral blood mononuclear cells (PBMC). The results have shown that these immune complexes are able to suppress cell reactivity by inducing an increase in the production of soluble mediators such as prostaglandins and IL-10. To gain a better understanding of how this suppression occurs the present study examines the phenotypic pattern of PBMC after immune complex treatment in cell proliferation assays. These data show that cultures including immune complex present a higher percentage of B lymphocytes in which a lower expression of a MHC-class II gene product, HLA-DR was detected. This altered expression of the HLA-DR molecule on B lymphocytes after IC treatment suggests a novel mechanism for the suppression observed, that is, IC might decrease the antigen-presenting function of B lymphocytes.
  • No Thumbnail Available
    Item
    Granulomatous hypersensitivity to Schistosoma mansoni egg antigens in human schistosomiasis. IV. A role for prostaglandin-induced inhibition of in vitro granuloma formation.
    (1994) Goes, Alfredo Miranda de; Rezende, Simone Aparecida; Gazzinelli, Giovanni; Doughty, Barbara L.
    The prostaglandins (PG) are known to regulate immune cell function (s) and participate in the progression of both acute and chronic inflammatory reactions. Using an in vitro model of Schistosoma mansoni egg-induced hypersensitivity granulomas, we have delineated the role of immune complexes (IC) in the induction andrelease of PG and their inhibitory effects on granuloma development. The hypersensitivity- type granuloma reaction to soluble egg antigen (SEA) was examined using a model of in vitro granuloma ,formation. Our results show that granuloma formation was dramatically suppressed by the addition to the granuloma cultures of IC, PGE,, PGE2, while PGF, alpha had no significant effect. The inhibition of the PG function was achieved by the introduction of anti-PG antibodies that blocked suppression of granuloma,formation. It appears in this model system that IC may inhibit the activity of granuloma formation by stimulating the monocyte-macrophage lineage to release inhibitory mediators. Our results suggest that the prostaglandins E series may be important in the generation and maintenance of suppression of the granulomatous inflammatory response to S. mansoni egg antigens .
  • No Thumbnail Available
    Item
    IL-10 plays a role in modulation of human granulomatous hypersensitivity against Schistosoma mansoni eggs induced by immune complexes.
    (1997) Rezende, Simone Aparecida; Teixeira, David Nascimento Silva; Drummond, Sandra Costa; Goes, Alfredo Miranda de
    It has been demonstrated that the chronic intestinal form of schistosomiasis is associated with the establishment and maintenance of a variety of immunoregulatory mechanisms that lead to a diminished granulomatous reaction to parasite eggs. Using an in vitro model of granuloma reaction we showed that immune complexes (IC) isolated from the sera of chronic intestinal schistosomiasis patients were able to reduce the granulomatous hypersensitivity (developed by peripheral blood mononuclear cells (PBMC) from schistosomiasis patients) to soluble egg antigen (SEA)-conjugated polyacrylamide beads (PB–SEA). This inhibitory activity, mediated by IC, was also observed in the proliferative response of PBMC stimulated with SEA and soluble worm antigen preparation (SWAP). Furthermore, we observed a decrease in TNF-α and an increase in IL-10 production by PBMC treated with IC in an in vitro granuloma reaction. This phenomenon was also seen in a cell proliferation assay when PBMC were treated with IC and stimulated with S. mansoni antigens. These results demonstrate that circulating IC may down-regulate PBMC reactivity to S. mansoni antigens by changing the cytokine pattern produced by these cells.
  • No Thumbnail Available
    Item
    Nitric oxide-mediated immune complex-induced prostaglandin E2 production by peripheral blood mononuclear cells of humans infected with Schistosoma mansoni.
    (1999) Neves, Simone M. F.; Rezende, Simone Aparecida; Goes, Alfredo Miranda de
    Granuloma reaction around Schistosoma mansoni eggs is the prominent lesion in human schistosomiasis. Studies have suggested the involvement of a series of suppressive mechanisms in the control of this reaction. Using an in vitro model of granuloma formation, we have shown that immune complexes (IC) isolated from sera of chronic intestinal schistosomiasis patients were able to reduce granulomatous reaction developed against soluble egg antigen-conjugated polyacrylamide beads. In this system, the role of the Larginine– nitric oxide (NO) pathway in the formation of prostaglandin E2 (PGE2) by human peripheral blood mononuclear cells (PBMC) of patients infected with schistosomiasis was investigated using IC. Preincubation of PBMC with IC produced a significant increase of both nitrite and PGE2 levels in the cell supernatant. This effect was inhibited by coincubation of cells with Nv-nitro-L-arginine methyl ester (L-NAME), a NO synthase inhibitor, showing that the release of PGE2 subsequent to IC stimulation was driven by NO. The inhibitory effect of L NAME on PGE2 release by ICtreated PBMC was reversed by sodium nitroprusside, a known NO donor. Our results indicate that NO could be an important second signal for the stimulation of PGE2 production induced by IC in PBMC from human schistosomiasis patients.
  • No Thumbnail Available
    Item
    Role of immune complexes from pacients with different clinical forms of Schistosomiasis in the modulation of in vitro granuloma reaction.
    (1997) Rezende, Simone Aparecida; Lambertucci, José Roberto; Goes, Alfredo Miranda de
    Schistosomiasis is a disease whose pathology is strongly related to the granulomatous reaction formed around parasite eggs trapped in host tissues. Studies have shown that the chronic intestinal form (INT) of this infection is associated with a variety of immunoregulatory mechanisms which lead to a diminished granulomatous reaction. Using an in vitro model of granuloma reaction, we show that immune complexes (IC) isolated from sera of INT patients are able to reduce granulomatous reaction developed by peripheral blood mononuclear cells (PBMC) from acute (AC), INT and hepatosplenic (HE) patients to soluble egg antigen (SEA)-conjugated polyacrylamide beads (PB-SEA). This inhibitory activity is also observed in cell proliferation assay of PBMC from INT and HE patients stimulated with SEA and adult worm antigen (SWAP). Furthermore, IC isolated from sera of patients with different clinical forms of the disease are also able to suppress INT patients PBMC reactivity. Therefore, our results show that circulating IC present in sera of patients with different clinical forms of schistosomiasis may downregulate PBMC reactivity to parasite antigens resulting in a diminished granuloma reaction to parasite eggs.