Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice

Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-γ, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-γ in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression

Estudo comparativo das infecções por Leishmania major e Leishmania amazonensis em camundongos isogênicos CBA

Submitted by Repositório Arca ([email protected]) on 2019-07-17T17:07:26Z No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2019-07-30T14:16:09Z (GMT) No. of bitstreams: 2 Valderes Lemos de Souza Estudo...1998.pdf: 58928303 bytes, checksum: 13ca01951d720f75f6730ea7fcff5aae (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-07-30T14:16:09Z (GMT). No. of bitstreams: 2 Valderes Lemos de Souza Estudo...1998.pdf: 58928303 bytes, checksum: 13ca01951d720f75f6730ea7fcff5aae (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 1998PAPES - 0250.250.354, CNPq - 523005/96-2Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil.A maioria dos trabalhos sobre o modelo murino na leishmaniose tegumentar utiliza diferentes linhagens de camundongos que são resistentes ou susceptíveis a uma determinada espécie de leishmânia ou trata de manipulações da resposta imune tornando camundongos susceptíveis, resistentes a determinada leishmânia, ou tornando resistentes, susceptíveis. No presente estudo avalia-se comparativamente, resistência e susceptibilidade à infecção por leishmânia, utilizando o modelo de infecção de camundongos isogênicos CBA infectados com L. amazonensis (L.a.), para as quais são susceptíveis, e infectados com L. major (L.m.), para as quais são resistentes. Nós comparamos a resposta imune-inflamatória nesses dois grupos através da avaliação do curso da infecção pelo monitoramento do tamanho das lesões e avaliação da quantidade de parasitos em cortes histológicos através de imunohistoquímica. A resposta tissular foi estudada em cortes histológicos das patas e dos linfonodos de drenagem no intervalo de três a 70 dias após a infecção. A produção de IFN-y, IL-4 e IL-10 foi avaliada pelo método ELlSA e a produção de NO pelo método de Griess, em sobrenadantes de culturas de células do linfonodo de drenagem. Os camundongos CBA infectados por L.m. controlam a infecção e curam, enquanto os infectados por L.a. exarcebam a infecção e morrem. Os padrões de resposta tissular no local da infecção e no linfonodo de drenagem são distintos. Nos animais resistentes ocorre inflamação mista com formação de granuloma e fibrose, enquanto nos susceptíveis ocorre reação macrofágica monomórfica, sem granulomas e fibrose. O IFN-y foi predominante produzido pelas células do linfonodo dos animais infectados por L.m., enquanto que os níveis de IL-4 foram mantidos mais alto no grupo de animais infectados por L.a., após o 7º dia de infecção. Os perfis distintos de resposta correspondem a padrões distintos de resposta tissular e estão relacionados com a produção aumentada de IFN-γ ou IL-4, ou seja perfis predominantemente Th1 ou Th2 da resposta imune celular. O padrão morfológico de resposta tecidual comporta-se como correlato da resposta imune. Os dados apresentados indicam que, no contexto do camundongo CBA, fatores relacionados com o parasito são determinantes do tipo da resposta imune-inflamatória.Resistance and susceptibility in experimental leishmaniasis have been well characterized in comparison studies of mice with different genetic backgrounds infected with a specific parasite species, such as Leishmania major However, there is evidence that several mouse strains can demonstrate resistance to infection with certain species of Leishmania and susceptibility to others. In order to investigate the induction of parasite specific resistance or susceptibility, we compared the patterns of tissular and immune responses in CBA mice against infection with L. major (L.m.) or Leishmania amazonensis {L.a.). During infections with L.m., lesions in CBA mice healed within 4 weeks of infections. In contrast, during infection with L.a, CBA mice developed progressive lesions that ulcerated by 9 week post-infection. Histologic studies demonstrated, that CBA mice infected with L.m., develop a mixed- mononuclear cell infiltrate. Parasitized macrophages were rarely observated, the number of lymphocytes increased progressively in the footpad, and fibrosis, fibrinoid necrosis foci and granulomas appeared after infection. In mice infected with L.a. there was a monotonous, "virchowian" infiltrate of heavily-parasitized macrophages. Necrosis, micro-abscess and skin ulceration were seen late in the course of infection. The profile of cytokine production differed in both groups. Cells from Lm-infected CBA mice produced high levels of IFN-y at all time points throughout infection. High levels of IL-4 were produced by cells obtained from L.a.-infected CBA mice. Such levels were maintained through the course of infection. The differing profiles of parasite induced resistence and susceptibility was associated with the type of inflammatory reaction and the levels of IFN-y or IL- 4 production. This results strongly suggest that in CBA mice, factors related with Leishmania species drive immune response to a predominately Th1 or Th2 pattern

Morphological and anatomical characterization of the digestive tract of Centropomus parallelus and Centropomus undecimalis - doi: 10.4025/actascibiolsci.v35i4.14352

Centropomus parallelus and Centropomus undecimalis are the most common species of Centropomidae in Brazil. Some authors attribute their failure to grow under in artificial conditions due to limited knowledge on the morphological and functional development of their digestive system and on nutrition requirements of both species. Current research characterizes histologically and histochemically the digestive tract of Centropomus parallelus and Centropomus undecimalis to provide a histophysiological assessment for studies related to their nutritional needs. In the esophagus, the mucous cells in the epithelium stained positively for PAS and AB. In the stomach, positive reactions to PAS and negative to AB respectively occurred on surface and mucous cells in the epithelium and in the lamina propria. In the intestine, goblet cells showed ratio similarity, with mucus being positive in AB and PAS. A greater concentration of these cells existed in the middle and distal intestine, with a greater increase of secretions when compared to those in the proximal intestine. Results show that Centropomus parallelus and Centropomus undecimalis display the main features of the digestive tract of carnivorous fish, a well-developed stomach and a relatively short intestine. In fact, they give insights for future studies on the mechanisms related to the species´s digestive and absorptive physiology.

Different Leishmania species determine distinct profiles of immune and histopathological responses in CBA mice.

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2012-10-02T21:28:31Z No. of bitstreams: 1 Lemos de Souza V Different Leishmania species ....pdf: 1728919 bytes, checksum: a7cec6a643500fdd07847eb76799775b (MD5)Made available in DSpace on 2012-10-02T21:28:31Z (GMT). No. of bitstreams: 1 Lemos de Souza V Different Leishmania species ....pdf: 1728919 bytes, checksum: a7cec6a643500fdd07847eb76799775b (MD5) Previous issue date: 2000Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilMost experimental studies on leishmaniasis compare two different inbred strains of mice that are resistant or susceptible to one species of Leishmania. In the present study we characterized some cytokines and nitric oxide production as well as histological changes related to resistance and susceptibility in isogenic CBA mice infected with Leishmania major or Leishmania amazonensis. CBA mice are capable of controlling infection with L. major, but they succumb to infection with L. amazonensis. Cells from susceptible L. amazonensis-infected CBA mice produced interleukin (IL)-4 and IL-10 but no interferon (IFN)-γ. On the other hand, resistant L. major-infected CBA mice produced IFN-γ and IL-10, but IL-4 was detected only in the first week of infection. Histopathological studies showed patterns of tissue responses at the site of the infection and in the draining lymph nodes that correlated with resistance or susceptibility. Resistant mice showed a mixed inflammatory cell infiltration and granulomas in the lesions, whereas in susceptible mice only heavily parasitized macrophages were seen. Our results indicate an important role of the parasite species in determining the pattern of immune response. L. amazonensis induces a Th2-type immune response, whereas L. major induces a Th1-type response. These factors must be identified and taken into account in the strategies for the development of vaccines against leishmaniasis. The model presented here will be useful for the study of such factors