RESUMO
Exposure of neonatal mice to appropriate, cross-reactive Id (CRI) preparations alters immune responsiveness, ameliorates pathology, and prolongs survival of animals upon subsequent Schistosoma mansoni infection. However, because schistosome infections profoundly affect host immunobiology, which responses are effected by neonatal Id exposure alone and which responses are influenced by infection is unclear. To directly examine the schistosome soluble egg Ag (SEA)-specific immune responses altered by CRI exposure, neonatal mice were injected with CRI-expressing (CRI+) SEA-specific Ab preparations, SEA-specific Abs that did not express CRI (CRI-), or normal mouse Ig. At 9 wk of age, only mice that were neonatally exposed to CRI+ anti-SEA Abs displayed significant SEA-specific IgG serum levels and spleen cell proliferative responses. SEA-stimulated spleen cells from these CRI+-exposed mice also produced IFN-gamma, although not at significantly higher levels than mice receiving CRI- Id or normal mouse Ig. If CRI+-exposed mice were also injected with SEA at 8 wk of age, the 9-wk IFN-gamma responses were significantly higher than those of the other neonatal injection groups. The presence of both CRI and anti-CRI in the sera of animals neonatally injected with CRI, but receiving no exposure to S. mansoni Ags or infection, suggested a functional idiotypic network led to these responses. These data demonstrate that appropriate idiotypic exposure induces B and T cell responsiveness to the Ag recognized by the Id and support the hypothesis that neonatal idiotypic exposure can be an important immunoregulatory factor in schistosomiasis.
Assuntos
Animais Recém-Nascidos/imunologia , Anticorpos Anti-Helmínticos/biossíntese , Antígenos de Helmintos/imunologia , Complexo CD3 , Imunização Passiva , Idiótipos de Imunoglobulinas/imunologia , Óvulo/imunologia , Schistosoma mansoni/imunologia , Animais , Anticorpos Anti-Idiotípicos/sangue , Antígenos de Helmintos/farmacologia , Reações Cruzadas , Feminino , Soros Imunes/farmacologia , Imunidade Celular , Imunização Passiva/métodos , Idiótipos de Imunoglobulinas/administração & dosagem , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos CBA , Coelhos , Receptores de Antígenos de Linfócitos T/imunologia , Baço/citologia , Baço/imunologiaRESUMO
The process of embryogenesis is described for the inarticulate brachiopod Discinisca strigata of the family Discinidae. A fate map has been constructed for the early embryo. The animal half of the egg forms the dorsal ectoderm of the apical and mantle lobes. The vegetal half forms mesoderm and endoderm and is the site of gastrulation; it also forms the ectoderm of the ventral regions of the apical and mantle lobes of the larva. The plane of the first cleavage goes through the animal-vegetal axis of the egg along the future plane of bilateral symmetry of the larva. The timing of regional specification in these embryos was examined by isolating animal, vegetal, or lateral regions at different times from the 2-cell stage through gastrulation. Animal halves isolated at the 8-cell and blastula stages formed an epithelial vesicle and did not gastrulate. When these halves were isolated from blastulae they formed the cell types typical of apical and mantle lobes. Vegetal halves isolated at all stages gastrulated and formed a more or less normal larva; the only defect these larvae had was the lack of an apical tuft, which normally forms from cells at the animal pole of the embryo. When lateral isolates were created at all developmental stages, these halves gastrulated. Cuts which separated presumptive anterior and posterior regions generated isolates at the 4-cell and blastula stages that formed essentially normal larvae; however, at the midgastrula stage these halves formed primarily anterior or posterior structures indicating that regional specification had taken place along the anterior-posterior axis. The plane of the first cleavage, which predicts the plane of bilateral symmetry, can be shifted by either changing the cleavage pattern that generates the bilateral 16-cell blastomere configuration or by isolating embryo halves prior to, or during, the 16-cell stage. These results indicate that while the plane of the first cleavage predicts the axis of bilateral symmetry, the axis is not established until the fourth cleavage. The development of Discinisca is compared to development in the inarticulate brachiopod Glottidia of the family Lingulidae and to Phoronis in the phylum Phoronida.
Assuntos
Crustáceos/embriologia , Animais , Blastocisto/fisiologia , Blastocisto/ultraestrutura , Linhagem da Célula , Crustáceos/crescimento & desenvolvimento , Embrião não Mamífero/fisiologia , Embrião não Mamífero/ultraestrutura , Endoderma/fisiologia , Gástrula/fisiologia , Gástrula/ultraestrutura , Larva , Morfogênese , Especificidade da EspécieRESUMO
Complementary DNA, encoding the mitochondrial enzyme NADH-ubiquinone oxidoreductase subunit 5 (SmND5) of the human parasite Schistosoma mansoni was isolated by screening a S. mansoni cDNA library with a human androgen receptor (hAR) cDNA probe. The complete nucleotide and deduced aminoacid sequences of SmND5 were determined. Southern blot analysis revealed the occurrence of a single copy gene for SmND5 and by means of RT-PCR, it was shown that sex- and stage-specific expression of SmND5 occurred. In order to establish a functional relationship between the mitochondrial enzyme and the androgen receptor, the effects of testosterone were compared to those of classical respiratory chain inhibitors, using adult schistosome and beef heart submitochondrial particles. Physiological concentrations of testosterone were able to inhibit the maintenance of proton gradient across the mitochondrial membranes, as well as ATP synthesis. The steroid was found to be cytotoxic to the larvae, but not to adult schistosomes. A model is proposed to explain the observed in vivo testosterone-related differences in worm burdens, in experimental chronic infections.
Assuntos
Mitocôndrias Cardíacas/metabolismo , NADH NADPH Oxirredutases/química , NADH NADPH Oxirredutases/genética , Schistosoma mansoni/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Abelhas/enzimologia , Caenorhabditis elegans/enzimologia , Bovinos , Clonagem Molecular , Sequência Consenso , DNA Complementar , Complexo I de Transporte de Elétrons , Biblioteca Gênica , Humanos , Mitocôndrias Cardíacas/efeitos dos fármacos , Dados de Sequência Molecular , NADH NADPH Oxirredutases/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Receptores Androgênicos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Schistosoma mansoni/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Partículas Submitocôndricas/efeitos dos fármacos , Partículas Submitocôndricas/metabolismo , Testosterona/farmacologiaRESUMO
The aim of this study was to examine three distinct groups of schistosomiasis patients and to determine whether cell phenotype profiles could be correlated with the different clinical forms of the disease. The data obtained indicate that Schistosoma mansoni infected patients have a lower percentage of CD3+ T cells than do non-infected individuals. Interestingly, infected patients presented more than twice the mean percentage of circulating activated T cells (CD3+HLA-DR+) when compared to the control group. Examination of T lymphocyte subpopulations showed that patients with the severe hepatosplenic form (HS) of the disease had lower levels of both CD8High+ and CD8Low+ cells when compared to the other groups of patients. All infected individuals had a higher percentage of circulating B cells, with an increase in the CD5+ B cell population that was more evident in the HS group. The data presented here are evidence to support a relationship between the hepatosplenic form of the disease, a decrease on the CD8+ cell population and an elevation on CD5+ B cells.
Assuntos
Linfócitos B/imunologia , Esquistossomose mansoni/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Animais , Antígenos CD/imunologia , Criança , Fezes/parasitologia , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Contagem de Ovos de Parasitas , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/classificaçãoRESUMO
Inbred male CBA/J mice with chronic Schistosoma mansoni infections develop two distinct syndromes. Hypersplenomegaly syndrome (HSS) demonstrates pathologic similarities to the hepatosplenic form of chronic human schistosomiasis, and moderate splenomegaly syndrome (MSS) resembles the asymptomatic intestinal form. Immunoaffinity-purified Abs against S. mansoni soluble egg Ags (SEA) from infected patients' sera differ idiotypically according to the donor's clinical form of the disease. We now show that immunoaffinity-purified anti-SEA Abs (Id) from MSS or HSS mice parallel idiotypic preparations of the analogous human clinical form by their differential ability to stimulate the proliferation of anti-Id T cells. MSS Id preparations stimulate spleen cells from either MSS or HSS animals. In contrast, HSS Id does not stimulate spleen cells from either group. In an anti-SEA ELISA, MSS and HSS Id preparations contained comparable levels of IgM and IgG1. However, the MSS Id preparation had higher levels of SEA-specific IgG2a and IgG2b than did HSS Id. The Ig isotypes of these Id preparations suggested differences in cytokine expression patterns. Studies of the cytokine profiles of the spleen cells responding to anti-SEA Id preparations demonstrated that while Id preparations from acutely infected mice stimulate IL-4 and IL-10 production, Id preparations from chronic MSS mice stimulate IFN-gamma production. HSS Id did not stimulate the production of any of these cytokines. The possibility that distinct immunoregulatory environments may contribute to the development of MSS and HSS correlates with earlier hypotheses that hepatosplenic pathology results at least in part from a lack of development or expression of appropriate regulatory Ids.
Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Citocinas/imunologia , Schistosoma mansoni , Esquistossomose mansoni/imunologia , Células Th1/imunologia , Adjuvantes Imunológicos , Animais , Humanos , Isotipos de Imunoglobulinas , Masculino , Camundongos , Camundongos Endogâmicos CBARESUMO
A monoclonal human anti-soluble schistosomal egg Ag(SEA) antibody (E5) that stimulates anti-Id T cells and is idiotypically represented in pools of immunoaffinity-purified human anti-SEA antibodies from chronic, generally asymptomatic, intestinal (INT) patients (AM1 and AM5) was used to raise several monoclonal anti-Id: 1C2, 1C6, 4A8, 4F9, and 2A7. Cross-inhibition between these anti-Id identified distinct idiotopes on E5. Anti-SEA preparations from schistosomiasis patients (AM1, AM5, and others) were tested for their inhibition of the E5/monoclonal anti-Id reactions, in competitive ELISA. In either the E5/4A8 or E5/1C6 ELISA system, anti-SEA from INT (AM1 or AM5) or hepatointestinal (HI) (AM7) patients were able to inhibit these reactions. However, anti-SEA antibodies from acute (AM9) or hepatosplenic (HS) (AM3 or AM8) patients did not express Id that were inhibitory in these systems. These results suggest that a relatively high proportion of INT and HI anti-SEA antibodies express a dominant cross-reactive idiotope (CRI) recognized by 1C6/4A8. This CRI is also easily detected in plasmas from individual INT patients. Anti-Id 1C2 reacted strongly with an Id in AM1, AM5, or AM7, but one which also occurred, to a lesser extent, in AM3, AM8, and AM9. Monoclonal anti-Id 4F9 and 2A7 reacted weakly with idiotopes expressed by antibodies from all patients, regardless of the clinical form of their infection. These observations indicate that anti-SEA antibodies from INT and HI, but not acute or HS patients express dominant, CRI that are identified by 1C6, 4A8, or 1C2 and are also expressed on the INT-derived anti-SEA mAb E5.
Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Anti-Helmínticos/imunologia , Anticorpos Monoclonais/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Antígenos de Helmintos/imunologia , Humanos , Idiótipos de Imunoglobulinas/imunologia , Peso Molecular , Óvulo/imunologia , SolubilidadeRESUMO
Immunoaffinity-purified antibodies against Schistosoma mansoni soluble egg Ag (SEA) from infected patients' sera differ idiotypically according to the donor's clinical form of the disease. The Id differ both by their ability to stimulate proliferation of anti-Id T cells and their recognition by anti-Id-specific sera. Also, mice infected with S. mansoni develop anti-Id T and B cell responses against mouse anti-SEA antibodies. We now show that anti-SEA antibodies from serum pools of chronic, but asymptomatic patients (AM1 and AM5) stimulate proliferation of spleen cells from mice infected with S. mansoni. However, AM8, anti-SEA antibodies from hepatosplenic patients, did not stimulate these spleen cells. The murine responses directly parallel patient studies where AM1 and AM5 Id-stimulated human PBMC, but AM8 Id did not. In competitive ELISA, using AM1 or AM-5-specific rabbit antisera or human anti-SEA mAb E5-specific rabbit antiserum, sera from mice infected for 8 and 16 wk (but not from uninfected mice) compete with AM1, AM5, or E5. These sera do not compete in the AM8/anti-AM8 competitive ELISA. Sera from 8-wk-infected mice inhibit more against AM1, AM5, and E5 than do sera from later infections, and anti-SEA immunoaffinity-purified antibodies from 8-wk-infected mice stimulate spleen cells from infected mice more than anti-SEA antibodies from sera of mice late in infection. However, spleen cells from more chronically infected mice are more responsive to either the murine or human anti-SEA antibody preparations than cells from mice with earlier infections. Both the ELISA data and lymphocyte responses indicate that anti-SEA antibodies from mice infected with S. mansoni for 8 wk bear Id cross-reactive with those expressed on anti-SEA antibodies from humans with chronic, asymptomatic schistosomiasis, but not those from hepatosplenic patients.
Assuntos
Anticorpos Anti-Helmínticos/análise , Antígenos de Helmintos/imunologia , Proteínas de Helminto , Idiótipos de Imunoglobulinas/análise , Esquistossomose mansoni/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos CBA , Coelhos , Schistosoma mansoni/imunologiaRESUMO
Natural killer (NK) activity was assayed in peripheral blood mononuclear cells of patients with schistosomiasis, of patients following treatment, and of uninfected control subjects. The patient populations were from villages in the Qalyub Province, Egypt and around Belo Horizonte , Brazil. NK activity was assayed by the cytotoxicity of 51Cr-labelled K562 target tumor cells. In neither infected population were significant alterations from normal levels found in the percent cytotoxicity per 10(6) cells, or in the lytic units that expressed 25% cytotoxicity. Likewise, prior treatment (2 and 6 months previously) did not alter the group NK activity detected. Similarly, in the Egyptian study there was no difference in the percentage of large granular lymphocytes between the infected and uninfected groups. In parallel studies in Egyptian and Brazilian schistosomiasis patients we did not find any evidence that this chronic infection consistently altered circulating NK activity.
Assuntos
Citotoxicidade Imunológica , Células Matadoras Naturais/imunologia , Esquistossomose/imunologia , Adolescente , Adulto , Idoso , Brasil , Criança , Egito , Humanos , Pessoa de Meia-Idade , Oxamniquine/uso terapêutico , Schistosoma mansoni , Esquistossomose/tratamento farmacológicoRESUMO
Plasma samples from St. Lucians were tested for the presence of antibodies which cooperate in vitro with normal human leukocytes in causing cytotoxic damage to schistosomula of Schistosoma mansoni. The in vitro antibody activity, which has been previously shown to depend on eosinophil effector cells was detected in 56% of the individuals with known, current S. mansoni infections and in 14% of control subjects from the same endemic area. Quantitatively, eosinophil dependent cytotoxic antibody (EDCA) activity, when expressed as the maximum amount of damage to schistosomula induced at high plasma concentration, correlated significantly with the intensity of S. mansoni infection as determined by fecal egg count, the highest levels of activity occurring in patients with stool counts of 60 eggs/ml or greater. In addition, plasma EDCA activity was found to correlate with the in vitro blastogenic responsiveness of patients' lymphocytes to three different parasite antigen preparations. In contrast, titrations of EDCA activity failed to reveal a relationship between EDCA titer and the most recent egg count performed on each subject. However, a significant correlation was observed when titers were compared to egg counts averaged over a 3-year period. Neither maximal EDCA activity nor titer was found to correlate with the duration of known schistosome infection.