Dermatofitose experimental do hamster inoculado com Trychophyton mentagrophytes na bolsa jugal

This study presents the results of T. mentagrophytes inoculation in the cheek pouch of the hamster, an immunologically privileged site. Forty two animals were used: 21 inoculated with 10(6) fungi in the cheek pouch (group 1) and 21 inoculated initially with 10(6) fungi in the foot pad and 15 days later in the cheek pouch, with the same amount of fungi (group 2). Animals were sacrificed at 20 hours, 3, 7, 14, 30, 60, and 120 days; samples from inoculated cheek pouch, and foot pads submitted to the foot pad test (FPT), were collected. Independent of group and time of evolution of infection, animals did not develop delayed hypersensitivity evaluated through the FPT. The pre-inoculation of fungi in the foot pad did not change the morphology of lesions induced in the cheek pouch. Therefore, in animals of group 1 and 2, the introduction of the fungus in the cheek pouch resulted in focal lesion composed of a sterile acute inflammatory infiltrate, with abscess formation that evolved to a macrophagic reaction, and later to resolution even in the absence of immune response detectable by FPT. Our results indicate that in spite of the important role of the immune response in the spontaneous regression of dermatophytosis, other factors are also an integral part in the defense against this fungal infection.Esse estudo apresenta os resultados obtidos quando da inoculação de Trychophyton mentagrophytes na bolsa jugal do hamster, local imunologicamente privilegiado. Foram utilizados 42 animais: 21 inoculados com 10(6) fungos na bolsa jugal (grupo 1) e, 21 inicialmente inoculados com 10(6) fungos no coxim plantar e, 15 dias após, na bolsa jugal com a mesma quantidade fúngica (grupo 2). Os animais foram sacrificados às 20 h, 3, 7, 14, 30, 60 e 120 dias; foram coletadas amostras da bolsa jugal inoculada, e das patas submetidas ao teste do coxim plantar (TCP). Independente do grupo e do tempo de evolução da infecção, os animais não desenvolveram hipersensibilidade tardia avaliada através do TCP. A pré-inoculação de fungos no coxim plantar não alterou a morfologia das lesões induzidas na bolsa jugal. Assim, nos animais do grupo 1 e grupo 2, a introdução do fungo na bolsa jugal, resultou em lesão focal, constituída por infiltrado inflamatório agudo estéril, com formação de abscesso, que evoluiu para reação macrofágica e, posteriormente, para a resolução mesmo na ausência de resposta imune detectável pelo TCP. Nossos resultados indicam que, apesar do importante papel da resposta imune na regressão espontânea da dermatofitose, outros fatores são, também, parte integral da defesa contra esta infecção fúngica

Contribuição ao estudo da reação á tricofitina nas dermatofitoses

The authors investigated the specific immunological competence of 31 patients with dermatophytosis using tricophytin antigen. Among them, 54.8% showed reaction to the delay phase (48 h) in the following proportions: tinea inguinale, 75%; tinea pedis, 61.5%; tinea unguium, 50% and tinea corporis, 20%. Other 62.5% showed positive result to the early phase (30 m). The association between these reactions revealed that, although the majority of cases with early positive reaction showed negativity to the delayed reaction, 20.8% presented positivity to both phases of the reaction. Out of the non-reactive patients to the delayed phase, 8 were submitted to the other cutaneous tests such as PPD, streptokinase, candidin, vaccinia and DNCB and showed preserved cellular immunity in 75%. These results suggest that, while using this reaction for immunological evaluation of patients with dermatophytosis, one should consider the overall immune status of the patient, the presence of early hypersensibility and the localization of the infection.Os autores investigaram a competência imunológica específica de 31 indivíduos portadores de dermatofitose, utilizando o antígeno tricofitina. Destes, 54,8% mostraram-se reatores à fase tardia dessa prova (48 h) nas seguintes proporções: tinea inguinale, 75%; tinea pedis, 61,5%; tinea unguium, 50% e tinea corporis, 20%. 62,5% dos casos apresentaram positividade à fase imediata (30 m) da reação. A associação entre essas reações revelou que, embora a maioria dos pacientes com reação imediata positiva apresentasse negatividade à reação tardia, 20,8% apresentaram positividade para as duas fases da reação. Dos pacientes não reatores à fase tardia, oito foram submetidos a outros testes cutâneos: PPD, estreptoquinase, candidina, vacínia e DNCB, verificando-se imunidade celular conservada em 75% dos casos. Estes resultados sugerem que, quando da utilização dessa prova na avaliação imunológica de pacientes com dermatofitose, deve-se considerar o estado imune geral do paciente, a presença de hipersensibilidade imediata e a localização da infecção

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster

No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5) Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mexicana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar.We have studied the role of the immune response in the morphology of the leishmaniotic granuloma induced in the cheek pouch of hamsters, an immunologically privileged site, after inoculation of 3 x 10(5) Leishmania mexicana. Animals were histologically and immunologically evaluated until 120 days after inoculation. Independent of the time of sacrifice, the animals were always non-reactors to the footpad test (FPT). At histology, the introduction of L. mexicana in the cheek pouch leads to an abscess that evolves to a granulomatous reaction rich in amastigote forms, and later it leads to resolution, even in the absence of immune response detectable by FPT. Our results demonstrate that the development of immune response is not preponderant for the control of infection induced by L. mexicana inoculated subcutaneously in the cheek pouch of the hamster. It also suggests that the macrophages present in the leishmaniotic granuloma are capable of eliminating this parasite, even in the absence of immune response evaluated by FPT

Trafficking of phagocytic peritoneal cells in hypoinsulinemic-hyperglycemic mice with systemic candidiasis

Background: Candidemia is a severe fungal infection that primarily affects hospitalized and/or immunocompromised patients. Mononuclear phagocytes have been recognized as pivotal immune cells which act in the recognition of pathogens, phagocytosis, inflammation, polarization of adaptive immune response and tissue repair. Experimental studies have showed that the systemic candidiasis could be controlled by activated peritoneal macrophages. However, the mechanism to explain how these cells act in distant tissue during a systemic fungal infection is still to be elucidated. In the present study we investigate the in vivo trafficking of phagocytic peritoneal cells into infected organs in hypoinsulinemic-hyperglycemic (HH) mice with systemic candidiasis. Methods: The red fluorescent vital dye PKH-26 PCL was injected into the peritoneal cavity of Swiss mice 24 hours before the intravenous inoculation with Candida albicans. After 24 and 48 hours and 7 days of infection, samples of the spleen, liver, kidneys, brain and lungs were submitted to the microbiological evaluation as well as to phagocytic peritoneal cell trafficking analyses by fluorescence microscopy. Results: In the present study, PKH+ cells were observed in the peritoneum, kidney, spleen and liver samples from all groups. In infected mice, we also found PKH+ cells in the lung and brain. The HH condition did not affect this process. Conclusions: In the present study we have observed that peritoneal phagocytes migrate to tissues infected by C. albicans and the HH condition did not interfere in this process. © 2013 Fraga-Silva et al.; licensee BioMed Central Ltd

Influence of Tumour Condition on the Macrophage Activity in Candida albicans Infection

To better understand the interactions between opportunistic fungi and their hosts, we investigated hydrogen peroxide (H(2)O(2)), nitric oxide and TNF-alpha production by peritoneal macrophages from Ehrlich tumour-bearing mice (TBM) during microbial infections. For this purpose, TBM at days 7, 14 and 21 of tumour progression were inoculated intraperitoneally with C. albicans and evaluated after 24 and 72 h. We observed that TBM showed significant increases in H(2)O(2), TNF-alpha levels and fungal clearance at day 7 after C. albicans infection. However, as the tumour advanced, there was a progressive decline in the release of H(2)O(2) and TNF-alpha that was paired with the dissemination of C. albicans. These results demonstrate that protective macrophage activities against Candida albicans are limited to the initial stages of tumour growth; continued solid tumour growth weakened the macrophage response and as a consequence, weakened the host's susceptibility to opportunistic infections.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

The effect of phosphoethanolamine intake on mortality and macrophage activity in mice with solid ehrlich tumors

The aim of the present study was to examine the effect of a diet rich in synthetic PEtn on the metabolism macrophages of tumor-bearing mice. The results demonstrated that PEtn increased the animals' survival time. In addition, the treated animals released smaller amounts of hydrogen peroxide (H2O2) and nitric oxide (NO) than the non-treated animals, particularly after day 14. From the results it could be concluded that H2O2 and NO were important in the modulation of neoplastic growth, and pointed to a promising role of PEtn in the control of human neoplasms.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Phenotypic and functional evaluations of peripheral blood monocytes from chronic-form paracoccidioidomycosis patients before and after treatment

Background: Paracoccidioidomycosis (PCM) is systemic mycosis caused by the thermal dimorphic fungus of genus Paracoccidioides, leading to either acute/subacute (AF) or chronic (CF) clinical forms. Numerous CF patients after treatment exhibit sequels, such as pulmonary and adrenal fibrosis. Monocytes are cells that are involved in the inflammatory response during active infection as well as in the fibrogenesis. These cells comprise a heterogeneous population with distinct phenotypic and functional activities. The scope of this study was to identify changes regarding functional and phenotypical aspects in monocytes comparing CF PCM patients on antifungal treatment versus non-treated patients (PMC-p).Methods: Twenty-three CF PCM composed of 11 non-treated patients (NTG) and 12 patients in apparent cure (ACG) were studied. Sixteen healthy individuals were used as control group (CG). Monocyte subsets were determined by immunophenotyping based on CD14 and CD16 expression. Cellular function was measured in vitro with and without stimulation with lipopolysaccharide (LPS) and P. brasiliensis exoantigen (PbAg) for 24 hours. Independent samples were compared using unpaired t tests, dependent samples were analyzed by paired t-test. Groups of more than two independent samples were analyzed using an ANOVA, with Tukey's post-test. Significance was set up at p < 0.05.Results: Our results showed high counts of peripheral blood CD14(+)CD16(+) and CD14(+)CD16(++) monocytes in untreated PCM-p accompanied by intense production of pro-inflammatory cytokines (IL-1 beta and TNF-alpha) and profibrotic growth factors (TGF-beta 1 and bFGF) by monocytes challenged with P. brasiliensis antigens. After the introduction of antifungal therapy, the counts of CD14(+)CD16(+) cells returned to baseline while CD14(+)CD16(++) counts remained high. Interestingly, counts of CD14(+)CD16(++) monocytes remained elevated even 52 +/- 7 months after successful antifungal treatment. Furthermore, the ACG-patients showed preserved pro-inflammatory activity in the presence of specific antigen stimuli and high spontaneous production of TNF-a by monocytes.Conclusions: Infection with Paracoccidioides leads to initiation of a specific proinflammatory response by monocytes of PCM-p during active disease and in the apparent cure. A profibrotic profile by monocytes was observed only at admission. Furthermore, PCM-p with apparent cure showed high spontaneous production of TNF-alpha and high counts of CD14(+)CD16(++) monocytes, probably induced by hypoxia duo to fibrotic sequelae.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP