Abstract Coculture of blood forms Trypanosoma cruzi with human PMBC suppresses the expression several molecules involved in lymphocyte activation, including receptors for IL-2. Our work was initially undertaken to establish whether this effect required physical parasite-PBMC contact or mediated by a T. secretion product. Using culture inserts cell-impermeable membranes, we were able demonstrate significant suppression PHA-induced lymphoproliferation trypanosomes placed same compartment as,...

Summary The platelets from normal rats interact with microfilariae of Dipetalonema viteae in vitro the presence antibodies leading to killing parasite. antibody involved this reaction is identified as IgE because absorption immune rat serum on anti‐rat column or pretreatment anti‐Fcɛ receptor resulted a significant reduction percentage microfilariae. This antibody, which mediates platelet activity towards microfilariae, appears early secondary infection and persists for short period time....

We studied the effects of Trypanosoma cruzi secretion products on capacity helper (Th) and cytotoxic (Tc) cells to express IL-2R, CD3, CD4, CD8 in response PHA or anti-CD3 stimulation. To this end, we used a culture system which blood forms parasite were cocultured with human PBMC. Two-color flow cytometry studies revealed that, under these conditions, there was significant decrease percentage both Th Tc expressing IL-2R (inhibition range = 30 65%). These already demonstrable 18 h after...

The levels of IFN-γ, TNF-α, IL-10, and TGF-β1 cytokines associated with Trypanosoma cruzi during pregnancy were determined by enzyme-linked immunosorbent assay (ELISA) in serum samples from peripheral, placental, cord blood chronic infected mothers detectable undetectable parasitemia, their uninfected newborns. Compared to pregnant women the concentrations IFN-γ higher at 3 sites parasitemia. In these newborns, TNF-α periphery comparison non-chagasic women. newborns parasitemia than IL-10...

Children in the Bolivian Andes are exposed to endemic infections and meager nourishment, live under poor hygienic conditions. The prevention of children malnutrition is a priority many countries including Bolivia. In this study, health status schoolchildren Taraco, Puna district, at 4,000 meters above sea level (masl) Caranavi, 650 masl wealthier subtropical valleys, was compared. weight, height, hematological biochemical parameters blood, parasites stool, clinical information 120 from rural...

We previously established that Trypanosoma cruzi, the causative agent of Chagas' disease, has ability to suppress expression p55 component IL-2R by activated human PBMC. explored in this work whether parasite alters high affinity IL-2R, responsible for internalization IL-2 and signal transduction. Radiobinding measurements revealed trypanosome indeed inhibited IL-2R. Thus, a considerably smaller number 125I-IL-2 molecules was necessary saturate on PHA-stimulated PBMC cocultured with T. cruzi...

The study aimed to measure the frequency of occurrence infections with helminths, protozoa, and risk factors undernutrition anemia among schoolchildren from Bolivian highland (altiplano) lowland (subtropical) rural regions, a high gastrointestinal parasite infections. Cross-sectional data were collected 790 children, 5–13 years old. Microscopic examination stool using Ritchie technique, hemoglobin testing HemoCue analyzer, anthropometric measurements performed. Over 60% 20% children infected...

In an attempt to investigate the effects of treatment human leishmaniasis, cytokines produced by peripheral blood mononuclear cells (PBMCs) patients with cutaneous leishmaniasis (CL) and mucocutaneous (MCL) under amphotericin B were determined during active disease from cocultures Leishmania (Viannia) braziliensis antigens. PBMC these exhibited a nonsignificant marginal increased production TNF-alpha upon antigen stimulation. However, same antigenic stimulus, MCL presented higher IFN-gamma...

Abstract We have previously reported ( Nature 1982. 299: 361) that the transplacental transfer of Dipetalonema viteae microfilariae (mf) can induce an antigen‐specific tolerance in rats. Rats thus tolerized serum factor(s) which block(s) lymphocyte proliferation. The results experiments involving fractionation antisera from tolerant animals indicate inhibitory activity for blastogenesis resides IgG antibodies. Absorption (eluted protein A) with specific filarial antigens reduced inhibition...

The purpose of this study was to evaluate the effects a crude Trypanosoma cruzi antigen (TCA) and its partially purified subfractions TCF1, TCF2 on peripheral blood mononuclear cells (PBMC) normal donors chagasic patients. TCF1 stimulated from patients in association with significant production interleukin (IL)-10. Only PBMC multiplied after incubation TCA released mainly interferon-γ but also IL-10. Neither IL-2 IL-4 nor CD4/CD8 ratios were changed culture antigens. These data suggest that...

Maternal parasitemia and placental parasite load were examined in mother–newborn pairs to determine their effect on the congenital transmission of Trypanosoma cruzi. Parasitemia was qualitatively assessed mothers newborns by microhematocrit test; determined tissues transmitting non-transmitting detection T. cruzi DNA histology. Compared transmitter mothers, frequency prevalence found be increased non-transmitter mothers; however, higher among than counterparts. Additionally, serum levels...

During acute infection, Trypanosoma cruzi, the etiologic agent of Chagas' disease, causes immunosuppression by mechanisms that are not fully delineated. Since mononuclear phagocytes major target cells in trypanosomiasis, we investigated monocytic function during T. cruzi infection. A series human monocyte and macrophage hybridomas, which represent clonal expansions subpopulations macrophages possess many normal functions, were successfully infected with cruzi. Clones 63 53, chosen for...

A competitive enzyme immunoassay based on the use of a monoclonal antibody (MAb) specific for "component 5" Trypanosoma cruzi was evaluated. The antigenicity and immunogenicity this component has been observed in natural experimental infections. studies were conducted an area Bolivia where mixed infections with Leishmania braziliensis are frequent present problem accurate diagnosis T. specificity sensitivity assay as compared to indirect immunofluorescence ELISA tests demonstrated. test...

Anemia is a health problem of concern among schoolchildren in underprivileged rural regions, where recurrent parasitic infections are common. A cross-sectional study was conducted 229 highland Bolivia the department La Paz, an area with high prevalence protozoan and helminth infections, to determine types mechanisms anemia. substantial proportion children (40.2%) were found be anemic based on hemoglobin measurements. No associations between low levels or when evaluating infectious causes...

Human Chagas' disease, caused by the protozoan Trypanosoma cruzi, is associated with pathological processes whose mechanisms are not known. To address this question, T cell lines were developed from chronic chagasic patients peripheral blood mononuclear cells (PBMC) and cloned. These clones (TCC) analyzed phenotypically monoclonal antibodies use of a fluorescence microscope. The surface phenotype TCC asymptomatic patient predominantly CD4 positive (86%). On contrary, CD8 was predominant in...