Foram selecionados aleatoriamente 38 cães naturalmente infectados por Leishmania (Leishmania) infantum chagasi oriundos de Araçatuba, São Paulo, área endêmica para leishmaniose visceral, e os quais foram distribuídos em dois grupos: o primeiro com 24 cães sintomáticos e, o outro, composto por 14 animais assintomáticos. Correlacionou-se a caracterização clínica (assintomáticos ou sintomáticos) com os: potencial em infectar o inseto vetor, padrão inflamatório da pele, perfil de imunidade celular e parasitismo tegumentar desses cães. Quanto ao número de formas amastigotas/mm2 no tegumento, não houve diferença estatisticamente significativa entre os grupos (p = 0,1584), sendo que a densidade de parasitos na pele mostrou uma correlação positiva moderada com os títulos de anticorpos anti-Leishmania (p = 0,042). Quanto à infectividade ao vetor, evidenciada pelo xenodiagnóstico, 16 (66,7%) cães sintomáticos e 13 (93%) assintomáticos foram capazes em transmitir Leishmania aos flebotomíneos, dentre estes, respectivamente, seis (37,5%) e oito (61,5%) animais não apresentavam parasitismo cutâneo, embora todos, de ambos os grupos, tenham sido positivos quando da pesquisa de parasitos no linfonodo poplíteo. Observou-se um maior percentual de transmissibilidade para o vetor a partir de cães assintomáticos (p = 0,0494). As alterações histológicas cutâneas foram similares em ambos os grupos e se caracterizaram, de modo geral, por um infiltrado inflamatório, ora focal ora difuso, na derme, constituído, principalmente, por células mononucleares (macrófagos, linfócitos e plasmócitos), variando de discreto a intenso. Quanto à caracterização da resposta imune celular no tegumento dos animais, somente a densidade (células/mm2) de células iNOS+ foi significantemente maior na derme dos cães sintomáticos quando comparado aos assintomáticos (p = 0,0368). Observou-se correlação positiva moderada entre a densidade de parasitos na pele e a densidade de macrófagos (p = 0,031), de células T CD4+ (p = 0,015) e CD8+ (p = 0,023), e, também, naquela de células iNOS+ relativamente a de células T CD3+ (p = 0,005), CD4+ (p = 0,001) e CD8+ (p = 0,0001). Verificou-se, ainda, correlação negativa moderada com o número de manifestações clínicas e/ou gravidade da enfermidade (p = 0,028), confirmando, assim, maior transmissibilidade de parasitos ao vetor, a partir de animais assintomáticos, demonstrando-se, dessa forma, que tais cães são fontes de infecção em potencial para insetos vetores em áreas endêmicas para leishmaniose visceral canina. / Thirty-eight dogs naturally infected by Leishmania (Leishmania) infantum chagasi were randomly selected from Araçatuba of São Paulo state (Brazil), an endemic area for visceral leishmaniasis. The subjects were distributed into two groups: the first comprising 24 symptomatic dogs and the second consisting of 14 asymptomatic dogs. Possible correlations of clinical characterization (in both symptomatic and asymptomatic subjects) with potential to infect the insect vector, skin inflammatory pattern, cutaneous cellular immunity profile and cutaneous parasitism were investigated. Regarding to the number of cutaneous leishmania amastigotes/mm2, there was not a significant difference between the groups (p = 0.1584); density of skin parasites showed a moderate positive correlation with anti-Leishmania antibody titers (p = 0.042). Concerning to the infectivity to the insect vector, as evidenced by xenodiagnosis, 16 (66.7%) symptomatic and 13 (93%) asymptomatic dogs were able to transmit Leishmania to phlebotomines. Among these, six (37.5%) and eight (61.5%) dogs, respectivelly, did not show cutaneous parasitism, although all participant dogs were found positive when searching for parasites in the popliteal lymph nodes. Asymptomatic dogs showed higher transmissibility to the vector than symptomatic ones (p = 0.0494). Histological features in the skin were similar in both groups and were generally characterized by an inflammatory infiltrate, either diffuse or focal, in the dermis, mainly consisted of mononuclear cells (macrophages, lymphocytes and plasma cells), varying from mild to intense. Concerning characterization of the cutaneous cellular immune response, only iNOS+ cells density (cells/mm2) was significantly higher in the dermis of the symptomatic dogs compared to the asymptomatic ones (p = 0.0368). Moderate positive correlation between the cutaneous parasites density and the macrophages density (p = 0.031), the CD4+ T cells (p = 0.015) and CD8+ T cells (p = 0.023) were observed. Furthermore, density of iNOS+ cells in relation to CD3+ T cells (p = 0.005), CD4+ T cells (p = 0.001) and CD8+ T cells (p = 0.0001) were found positively correlated at a moderate level. It was also found a moderate negative correlation between cutaneous parasites density and the number of clinical signs and/or disease severity (p = 0.028), confirming grater parasites transmission to the vector from asymptomatic animals. It was therefore demonstrated that these dogs are potential sources of infection to insect vectors in endemic areas for canine visceral leishmaniasis.

O ferro é um elemento chave em muitos processos metabólicos, como transporte de oxigênio, síntese de hormônios esteróides, respiração celular, transporte de elétrons, síntese de DNA, proliferação e diferenciação celular e regulação gênica. A deficiência de ferro é a desordem nutricional mais comum afetando aproximadamente um terço da população mundial. Pequenos déficits no compartimento funcional de ferro têm sérias conseqüências sobre o sistema imune, principalmente na imunidade mediada por células. A abordagem dos pais ou responsáveis, as exigências éticas e a aderência de crianças da mesma faixa etária e sem outros problemas que afetem o metabolismo do ferro e o sistema imune são as principais dificuldades enfrentadas no desenvolvimento de pesquisas com seres humanos, sendo necessário o estabelecimento de modelos experimentais. Este trabalho teve como objetivo estabelecer um modelo de indução e recuperação de deficiência de ferro em camundongos, visando a sua utilização em estudos sobre alterações do sistema imune induzidas por esta deficiência. A deficiência de ferro foi induzida por ingestão de uma ração com baixo teor de ferro (5 mg /kg de ração) por 4 e 8 semanas. No termino deste período foram determinados: concentração de hemoglobina (colorimetrico), hematócrito (microhematócrito), estoques de ferro hepático (espectrometria de absorção atômica) e fenotipagem (citometria de fluxo) dos linfócitos presentes no sangue periférico e em suspensão de células do baço dos animais dos grupos controle (C) e deficiente em ferro (DF), sendo avaliado a porcentagem de células T CD4+ e CD8+, bem como a expressão do receptor de transferrina (CD71+) nessas subpopulações. Não houve diferenças na concentração de hemoglobina e no valor do hematócrito entre os animais dos grupos DF e C, porém os estoques de ferro estavam significantemente reduzidos nos animais do grupo DF de quatro (p<0,05) e oito (p<0,01) semanas. Não houve diferenças na porcentagem de linfócitos T CD4+ e T CD8+ entre os animais dos grupos DF e C, porém os animais deficientes em ferro apresentaram maior porcentagem de linfócitos T CD8+ do baço expressando CD71+ (p< 0,001). Este trabalho sugere que a depleção nos estoques de ferro não altera a proporção dos subtipos de linfócitos, porem as células T CD8 + do baço são mais sensíveis à deficiência de ferro. / Iron have a crucial role in several metabolic pathways, such oxygen transport, steroid hormone synthesis, cellular respiration, electron transport, DNA synthesis, cellular proliferation and differentiation and genic regulation. The iron deficiency is most common disorder nutrition, affecting about 30% world population. Deficits in iron functional compartment have serious delays about immunity systems, especially in the cellular immunity. Because of environmental problems, age, deficiency of nutrients other than iron, prevalence of infection, which may make human studies difficult, we used an animal model. This work aimed established iron deficiency induction and recuperation in mouse, for study about immune systems alteration. Iron deficiency was induced by feeding mice a diet that contained only 5 mg Fe/Kg for 4 and 8 weeks. After this period were determined: hemoglobin (colorimetry), hematocrit (microhematocrit), liver iron stores (atomic absorption spectrophotometer) and we performed a flow cytometry analyses in peripheral blood and spleen lymphocytes in control (C) and iron deficient (ID) mouse. We defined the effects of iron deficiency on T-cell subset and expression of cell-surface transferrin receptor (CD71+) in these cells. Hemoglobin concentration and hematocrit of ID mice were not difference those of C mice, but iron stores of ID mice (4 and 8 weeks) were reduced (p< 0,05 and p< 0,01; respectively). Although T-cells subsets in peripheral blood and spleen were not altered, iron deficiency significantly increased the number of spleen T CD8+ cells that express CD 71+ (p< 0,001). Data suggest that depletion of iron storage not alter T-cells subsets and spleen T CD8+ is the most sensible subset in iron deficiency.

A Paracoccidioidomicose é micose sistêmica causada pelo fungo Paracoccidioides brasiliensis, endêmico na América Latina, especialmente Brasil. Para melhor avaliarmos a resposta imune celular frente a diferentes componentes do fungo, como gp43, considerada o antígeno imunodominante de P. brasiliensis, filtrado de cultura livre de gp43 (Filtrado), e gp43 tratada com metaperiodato (meta), utilizamos os ensaios de linfoproliferação e ELISA para detecção das citocinas IL-4, IL-10, IL-12 e IFN-. Os resultados com relação à gp43 corroboram dados da literatura e de nosso laboratório demonstrando que gp43 é o antígeno imunodominante do fungo e pode estar envolvido no mecanismo de anergia dos linfócitos T de pacientes com a micose ativa. Com o Filtrado observamos respostas linfoproliferativas positivas, porém menores que com gp43, também evidenciando a anergia de linfócitos T de pacientes, e a indução de IL-10 em células de controles curados, podendo representar assim um mecanismo de imunossupressão. Com relação à meta, esta não induziu resposta linfoproliferativa nem a síntese de citocinas, sugerindo não ser um antígeno apropriado para esse tipo de avaliação. / Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis, endemic in latin América, specially Brazil. To better understand the cellular immune responses to different components of the yeast, such as gp43, considered the immunodominant antigen, a culture filtrate free of gp43 (CF), and gp43 treated with metaperiodate, we used lymphoproliferative assays and ELISA to detect the cytokines IL-4, IL-10, IL-12 e IFN-. The results with gp43 were consistent with the literature and previous with data from our Laboratory showing that gp43 is the immunodominant antigen of P. brasiliensis and is likely involved with the anergy of T-cells from patients. With CF we observed positive, but weaker, proliferative responses. It also evidenced the T-cell anergy of patients and the preferential induction of IL-10 in cells from cured controls. The latter can represent a mechanism of anergy induction. With meta, we observed that neither induce proliferative responses nor cytokine secretion, being apparently an inappropriate antigen for use in cellular immunoassays.

Abstract not available

Abstract not available

[Truncated abstract] HIV infection compromises the ability of the host to mount effective immune responses. In untreated HIV disease, immune activation drives high rates of cell turnover and apoptosis, ultimately leading to abnormal and dysregulated cellular function. Immune activation may also induce the expansion of CD4+ regulatory T (Treg) cell populations capable of suppressing anti-HIV responses. Treatment with antiretroviral therapy (ART) allows the recovery of CD4+ T cell numbers in most patients. Persistent deficiencies in the number and function of CD4+ T cells seen in a proportion of individuals may reflect elevated numbers of Treg cells or an imbalanced regulatory-to-effector cytokine milieu. Furthermore, some patients develop paradoxical illnesses associated with the recovery of cellular function, known as immune restoration disease (IRD). The first part of this thesis addresses the role of CD4+ Treg cells in untreated and treated HIV disease. The second part addresses the phenotype of immune cells that express IL-10 and its receptor in untreated and treated patients, and the role of IL-10 in mycobacterial IRD. Firstly, several cell surface markers were evaluated to find a flow cytometry assay that could be used routinely to identify CD4+ Treg cells in HIV-infected patients. I tested CD25, GITR, CTLA-4, NRP-1 and LAG-3, but their expression did not mirror the expression of FoxP3, an intracellular transcription factor specific to CD4+ Treg cells (Chapter 2). Two published studies then described the use of CD127 to identify CD4+FoxP3+ Treg cells in humans. Using CD127, I determined the proportions and numbers of CD4+ Treg cells in untreated HIV-infected patients and in patients in their first year of ART. Proportions of CD4+ Treg cells correlated with the proportions of activated (HLA-DRHI) CD4+ T cells and with plasma HIV RNA levels in untreated patients, but showed an inverse correlation with CD4+ T cell count. In both untreated and treated patients, the proportions and numbers of FoxP3+ cells that expressed CD8 were significantly higher than in uninfected donors. This was clearest in patients with CD4+ T cell counts below 300/'L (Chapter 3). This body of work suggests that the frequencies of CD4+ Treg cells are directly related to the level of HIV-associated immune activation. Phenotyping of FoxP3+CD4+ Treg cells in untreated and treated patients and in uninfected donors revealed that co-expression of CD45RO, CD28, CTLA-4 and markers of activation were similar in all HIV-infected patients and controls. ii FoxP3+CD8+ T cells exhibit lower levels of CD45RO, CD28 and CTLA-4, but higher expression of PD-1 and CD57 (Chapter 4). This suggests that FoxP3+CD8+ T cells may have a reduced functional capacity. It is unclear whether they have regulatory activity by virtue of FoxP3 expression. ... Both patients produced higher levels of IFN? compared with IL-10 in response to mycobacterial antigens. In contrast, patients who experienced uneventful immune reconstitution produced higher levels of IL-10 (Chapter 6). Part 1 of this thesis highlights the importance of using specific cellular markers to identify CD4+ Treg cells, and confirms CD127 as a valuable marker for routine monitoring of blood Treg cells. Part 2 of this thesis demonstrates the important regulatory role of IL-10 in patients receiving ART.

Includes bibliographical references (leaves 169-205). / xvii, 205, [33] leaves, [10] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Suggests that the testicular macrophage exhibits characteristics similar to that of a suppressor macrophage phenotype. The inhibition of lymphocyte proliferation by the testicular macrophage, its unique cytokine profile, high basal production of GM-CSF and prostaglandins, and the refractoriness to LPS all suggests a role that contributes to the immune privilege that is afforded the testis. However, these aspects of testicular macrophage immuno-biology also support a role in local cell-cell communication and regulation of the normal physiology of the testis, and macrophages may be directly involved in Leydig cell steriogenesis. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1997?

Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Pharmaceutical Sciences. Title from pdf file main screen (viewed on February 17, 2010). Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 243 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 213-240).

published_or_final_version / abstract / toc / Zoology / Master / Master of Philosophy