RESUMO
Cell invasion by the intracellular protozoans requires interaction of proteins from both the host and the parasite. Many parasites establish chronic infections, showing they have the potential to escape the immune system; for example, Trypanosoma cruzi is an intracellular parasite that causes Chagas disease. Parasite internalization into host cell requires secreted and surface molecules, such as microvesicles. The release of microvesicles and other vesicles, such as exosomes, by different eukaryotic organisms was first observed in the late twentieth century. The characterization and function of these vesicles have recently been the focus of several investigations. In this review, we discuss the release of microvesicles by T. cruzi. The molecular content of these vesicles is composed of several molecules that take place during parasite-host cell interaction and contribute to the parasite-driven mechanism of evasion from the host immune system. These new findings appear to have a profound impact on the comprehension of T. cruzi biology and highlight novel potential strategies for developing more efficient therapeutic approaches.
Assuntos
Endocitose , Interações Hospedeiro-Parasita , Vesículas Secretórias/metabolismo , Trypanosoma cruzi/fisiologia , Fatores de Virulência/metabolismo , Trypanosoma cruzi/metabolismoRESUMO
BACKGROUND: Leishmaniasis causes alterations and lesions in the genital system, which leads to azoospermia and testicular atrophy in animals during the chronic phase of the infection. The aim of this study was to reveal the kinetics of Leishmania chagasi infection in the genital system of male golden hamsters (Mesocricetus auratus). METHODS: Animals were intraperitoneally inoculated with amastigotes from L. chagasi. At different time points animals were euthanized and genital organs processed for histo-pathological, qPCR, cytokines and testosterone detection assays. RESULTS: Our results showed a high parasite load in testis, followed by an increase of pro-inflammatory cytokines IL1-ß, TNF-α and IFN-γ, and testosterone. Subsequently, IL-4 expression was upregulated and basal parasite persistence in testis was observed using the experimental approach. CONCLUSION: Extracellular amastigotes migrated to the epididymis posing as a potential major factor of parasite persistence and venereal transmission of L. chagasi infection in hamsters.
Assuntos
Genitália Masculina/parasitologia , Leishmania/fisiologia , Leishmaniose Visceral/parasitologia , Animais , Cricetinae , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Genitália Masculina/patologia , Humanos , Cinética , Leishmania/química , Leishmania/genética , Leishmania/crescimento & desenvolvimento , Leishmaniose Visceral/genética , Leishmaniose Visceral/metabolismo , Leishmaniose Visceral/patologia , Masculino , MesocricetusRESUMO
Trypanosoma cruzi has high biological and biochemical diversity and variable tissue tropism. Here we aimed to verify the kinetics of cytokine and chemokine in situ secretion in animals infected with two distinct T. cruzi strains after oral inoculation. Also, we investigated parasite migration, residence and pathological damage in stomach, heart and spleen. Our results showed that host immune response against T. cruzi infection is an intricate phenomenon that depends on the parasite strain, on the infected organ and on the time point of the infection. We believe that a wide comprehension of host immune response will potentially provide basis for the development of immunotherapeutic strategies in order to clear parasitism and minimize tissue injury. In this context, we find that KC poses as a possible tool to be used.
Assuntos
Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Trypanosoma cruzi/imunologia , Animais , Doença de Chagas/veterinária , Feminino , Coração/parasitologia , Camundongos , RNA Mensageiro/metabolismo , Baço/parasitologia , Estômago/parasitologiaRESUMO
BACKGROUND: P21 is a secreted protein expressed in all developmental stages of Trypanosoma cruzi. The aim of this study was to determine the effect of the recombinant protein based on P21 (P21-His(6)) on inflammatory macrophages during phagocytosis. FINDINGS: Our results showed that P21-His(6) acts as a phagocytosis inducer by binding to CXCR4 chemokine receptor and activating actin polymerization in a way dependent onthe PI3-kinase signaling pathway. CONCLUSIONS: Thus, our results shed light on the notion that native P21 is a component related to T. cruzi evasion from the immune response and that CXCR4 may be involved in phagocytosis. P21-His(6) represents an important experimental control tool to study phagocytosis signaling pathways of different intracellular parasites and particles.