Transforming growth factor-β and matrix metalloproteinase secretion in cell culture from ex-vivo pbmc after exposure to uv radiation.

Transforming Growth Factor-beta (TGF-beta) and Matrix metalloproteinases (MMPs) especially MMP-2 and MMP-9, secreted by a pool of cells from dermic-epidermic tissue, might be associated with a poor prognosis of cancer. We examined the effect of solar radiation on the secretion of TGF-beta, MMP-2 and MMP-9 by ex vivo PBMC and dermic-epidermic cell pool. The two pools of cells in culture were photo tested using a solar simulator which reproduces the natural light source. The cells were incubated in serum-free medium in the absence and presence of PHA. After two 5 and 45 min exposure times, the supernatant of the cultures was removed at 24 and 48 h and analyzed for TGF-beta, and disrupted cell samples for MMP-2 and MMP-9 by RT-PCR. The data obtained by Optical Density by ELISA showed significant differences in the production of TGF-beta to the exposed cultures compared to control at 24 and 48 h, respectively. The increases in the MMP-2 and MMP-9 concentrations depending on the exposure time were observed. In conclusion, the UV radiation emitted by the solar simulator was able to stimulate the cells from extracellular matrix in in vitro culture to TGF-beta production, MMP-2 and MMP-9 expressions and their mRNAs. Since such MMPs and TGF are related to the evolution of cancer and its pathogenesis, these findings confirm that UV radiation can contribute to the prognosis of such diseases based on the MMP and TGF-beta secretion.

Phenotypic behavior of PBMCs from irradiated dogs based on flow cytometry.

The present paper investigates the phenotypic parameters of stimulation markers and cell immunosuppression markers in an animal model using flow cytometry analysis. Six dogs were exposed to 2, 4 or 6 Gy following a head and neck protocol. Samples of peripheral blood mononuclear cells (PBMCs) were collected before irradiation, representing standard values for all dogs (control), and at 2 h, 18 h and 30 d after irradiation. Such samples were separately assessed for surface markers with the monoclonal antibodies anti-CD5, anti-CD4 and anti-CTLA-4 by flow cytometry. A reduction in Tcell expression of CD5 and in the subpopulation expressing CD4 and an increase in CTLA-4 expression were found. No statistically significant differences were observed for the absorbed dose grouping, although the time kinetics were recorded. Radiation induced phenotypic differences between the lymphocyte lineages, reducing the CD5 and CD4 Tcell subpopulations and increasing CTLA-4 expression. The findings demonstrate the relevance of investigating the immunophenotype of irradiated subjects by examining the peripheral cell lineage.

Schistosoma mansoni PIII antigen modulates in vitro granuloma formation by regulating CD28, CTLA-4, and CD86 expression in humans.

We investigated the in vitro responses of peripheral blood mononuclear cells (PBMC) from intestinal chronic schistosomiasis patients to PIII, a multivalent antigen prepared from Schistosoma mansoni adult worm. PIII decreased cellular proliferation and granulomatous reaction. Moreover, induced the reduction of IFN-gamma levels and increased IL-10 production. To better understand the mechanism through which the observed suppression occurs, the present study focused on the phenotypic pattern displayed by PBMC treated with PIII in an in vitro granuloma assay. Expression of the surface markers CD28, CTLA-4 and CD86 by lymphocytes and monocytes were analyzed by flow cytometry. Our results demonstrated a significant decrease of CD28+CD4+ and CD28+CD8+ T-cell percentage stimulated by PIII compared to its non-infected counterparts. This suppressive effect was related to a significant increase in the percentage of T-cells expressing CTLA-4. PIII also promoted a significant increase in the percentage of cells expressing CD86. Indeed, our results demonstrated that PIII was capable of modulating in vitro granuloma reaction, and this event was related to the balance of IL-10, IFN-gamma and CD28, CTLA-4, CD86 bringing new insight to the immunoregulation of granulomatous hypersensitivity in human schistosomiasis.

Cytokines as determinants of resistance and pathology in human Schistosoma mansoni infection.

The role of different cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar results were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-gamma in the supernatants showed that PBMC from INT patients secreted low levels of IFN-gamma upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-gamma. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-gamma may be associated with resistance to infection.

The ecology of Triatoma sordida in natural environments in two different regions of the state of Minas Gerais, Brazil.

A study was undertaken about T. sordida in the natural environment in two different regions of the state of Minas Gerais: Itapagipe (Triângulo), an area of cerrado modified by the formation of fields of pasture and agriculture, and Mato Verde (north) an area of transition between caatinga and cerrado with profound deforestation in the last years due to the expansion of cotton cultivation. In both regions the principal ecotopes identified were hollow trees and the bark of live or dead trees, where the occurrence of a food source is not frequent. In this environment, the triatomines utilize various food sources; opposums appear to represent an important source of infection. In the north of Minas, a greater concentration of reservoirs and vectors was observed than in the Triângulo which could explain the higher level of infection of the triatomines in the north. Close attention to the process of domiciliation of T. sordida in the north of Minas is recommended where an extensive intervention by man in the natural environment has occurred and where a rise in the population of triatomines in the peridomestic environment has been observed in recent years.

Evaluation of the Chagas' disease vector control program in Minas Gerais, Brazil, with special reference to Triatoma sordida.

As of 1979, data gathered by the Chagas' Disease Control Program (CDCP) in the Brazilian state of Minas Gerais indicated that Triatoma infestans was the Chagas' disease vector most commonly found in and around human dwellings. A decade later, however, this picture had changed, presumably as a result of control efforts; few specimens of T. infestans were collected; and Triatoma sordida had become the most commonly collected vector insect. The aim of the work reported here was to assess the effectiveness of the CDCP in Minas Gerais in 1979-1989, with special reference to T. sordida. For this purpose, 1979-1989 triatomine collection data were reviewed for the two Minas Gerais health districts (Montes Claros and Uberaba) believed to have the heaviest T. sordida infestations. In addition, 1987 data from a serologic survey for human Trypanosoma cruzi infections in seven municipalities of these regions were compared with earlier (1978) serologic data from the same locales. In general, the triatomine collection data documented the precipitous decline of T. infestans in and around human dwellings. They also indicated that while the T. sordida collections had remained stable (in Uberaba) or increased markedly (in Montes Claros), there had been no great upsurge in the numbers of T. sordida collected inside dwellings. It was concluded that control measures were preventing extensive house reinfestations in both Montes Claros and Uberaba; that the situation in Uberaba was relatively stable; and that the marked increase in T. sordida populations around homes in Montes Claros was associated with forest clearing and changing settlement patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell-mediated immunity to schistosomes. Evaluation of mechanisms operating against lung-stage parasites which might be exploited in a vaccine.

This report describes parallel studies examining T cell and cytokine responses to Schistosoma mansoni in mice and man. The prevalence of IFNg production amongst murine (C57BL/6) T cell lines and clones, plus good DTH reactivity by IFNg-secreting clones, highlights the predominance of the Th1 response in the pulmonary immunity characteristics of the murine irradiated vaccine model. In human studies, effects of anti-cytokine antibodies on the proliferation of PBMC from human patients to various soluble schistosome antigen preparations have been examined. Data suggest that both Th1 (against early antigens) and Th2 (against late antigens) responses are present. A role for IL-10 is highlighted in chronic intestinal, but not acute or chronic hepatosplenic patients, as a downregulator of responses which are associated with morbidity and are against late stage antigens.

Cytokine regulation of human immune response to Schistosoma mansoni: analysis of the role of IL-4, IL-5 and IL-10 on peripheral blood mononuclear cell responses.

The role of cytokines on the in vitro proliferative response of peripheral blood mononuclear cells (PBMC) from Schistosoma mansoni infected patients to soluble egg (SEA) and adult worm antigens (SWAP) were evaluated. The results obtained demonstrated that the proliferative response of PBMC from chronic intestinal (INT) patients to SEA and SWAP is increased by the blockage of IL-10 with specific monoclonal antibodies (MAb). The effects of these antibodies were readily reversed by the addition of recombinant IL-10. In contrast, no effect was observed on the PBMC response of acute and hepatosplenic patients (HS) in the presence of anti-IL-10. Anti-IL-4 antibodies decreased the PBMC response of the intestinal (INT) and HS individuals to SEA and SWAP, and the PBMC response of acute patients to SEA but not to SWAP. Addition of anti-IL-5 MAb did not decrease the PBMC response of acute patients to SEA or SWAP. These results suggested that IL-10 has an important role in the modulation of the immune response in chronic asymptomatic patients and that this cytokine may be an important factor in controlling morbidity.

Human Schistosomiasis mansoni: IL-10 modulates the in vitro granuloma formation.

Granuloma formation and modulation around Schistosoma mansoni eggs that are trapped in host tissues play a pivotal role during schistosomiasis. It has been demonstrated that the granuloma reactions differ in patients with the different clinical forms of the disease. The pathology during murine schistosomiasis has been correlated with a Th2 response while resistance to infection with a Th1 type response. In humans, very little is known about the role of different cytokines on the development of the disease. Here we demonstrate that IL-10 is an important cytokine regulating the in vitro granulomatous reactivity of PBMC from intestinal (INT) patients. This was evidenced by the fact that blockage of this cytokine in the in vitro granuloma assay lead to a significant increase in granuloma size with cells from INT patients but not with individuals in the acute phase or with the hepatosplenic (HS) form of schistosomiasis. These results demonstrate for the first time that, in context with the model, a Th2 cytokine in human schistosomiasis plays an important role in controlling morbidity.

Cytokines as determinants of resistance and pathology in human Schistosoma mansoni infection

The role of diferent cytokines in the peripheral blood mononuclear cell (PBMC) proliferative response and in in vitro granuloma formation was evaluated in a cross-sectional study with patients with the different clinical forms and phases of Schistosoma mansoni infection, as well as a group of individuals "naturally" resistant to infection named normal endemic (NE). The blockage of IL-4 and IL-5 using anti-IL-4 and anti-IL-5 antibodies significantly reduced the PBMC proliferative response to soluble egg (SEA) and adult worm (SWAP) antigens in acute (ACT), chronic intestinal (INT) and hepatosplenic (HS) patients. Similar esults were obtained in the in vitro granuloma formation. Blockage of IL-10 had no significant effect on either assay using PBMC from ACT or HS. In contrast, the addition of anti-IL-10 antibodies to PBMC cultures from INT patients significantly increased the proliferative response to SEA and SWAP as well as the in vitro granuloma formation. Interestingly, association of anti-IL-4 and anti-IL-10 antibodies did not increase the PBMC proliferative response of these patients, suggesting that IL-10 may act by modulating IL-4 and IL-5 secretion. Addition of recombinant IL-10 decreased the proliferative response to undetectable levels when PBMC from patients with the different clinical forms were used. Analysis of IFN-gamma in the supernatants showed that PBMC from INT patients secreted low levels of IFN-gamma upon antigenic stimulation. In contrast, PBMC from NE secreted high levels of IFN-gamma. These data suggest that IL-10 is an important cytokine in regulating the immune response and possibly controlling morbidity in human schistosomiasis mansoni, and that the production of IFN-gamma may be associated with resistance to infection.