RESUMO
The study describes the occurrence of cysticercosis in liver of 22 wild agoutis (Dasyprocta leporina) in the Brazilian Amazon. The phylogenetic analysis and microscopic characteristics of metacestodes in liver tissue sections, associated with the geographic distribution of the intermediate hosts indicated that a possibly novel Taenia sp. metacestode caused the parasitism. Additionally, two cases of hepatic co-infection by Taenia sp., Calodium sp. and Echinococcus oligarthra were also observed among the analyzed animals. The results point to the need for a better understanding of hepatotropic parasites among wild rodents in the Brazilian Amazon.(AU)
O estudo descreve a ocorrência de cisticercose no fígado de 22 cutias (Dasyprocta leporina) silvestres da Amazônia brasileira. A análise filogenética e as características microscópicas dos metacestódeos em cortes histológicos de fígado, associadas à distribuição geográfica do hospedeiro intermediário, indicaram que, possivelmente, uma nova espécie de Taenia sp. Causou o parasitismo. Adicionalmente, dois casos de co-infecção por Taenia sp., Calodium sp. e Echinococcus oligarthra também foram observados entre os animais avaliados. Os resultados apontam para a necessidade de um melhor entendimento dos parasitas hepatotrópicos entre roedores selvagens da Amazônia brasileira.(AU)
Assuntos
Animais , Doenças Parasitárias em Animais/diagnóstico , Cisticercose/diagnóstico , Doenças Negligenciadas/diagnóstico , Dasyproctidae/parasitologia , Filogenia , Taenia/patogenicidade , Capillaria/patogenicidade , Echinococcus/patogenicidadeRESUMO
Chronic inflammation of the intestinal mucosa is characteristic of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Helminth parasites have developed immunomodulatory strategies that may impact the outcome of several inflammatory diseases. Therefore, we investigated whether Taenia crassiceps infection is able to decrease the inflammatory effects of dextran sulfate sodium- (DSS-) induced ulcerative colitis in BALB/c and C57BL/6 mice. Preinfection significantly reduced the manifestations of DSS-induced colitis, as weight loss and shortened colon length, and decreased the disease activity index independently of the genetic background of the mice. Taenia infection decreased systemic levels of proinflammatory cytokines while increasing levels of IL-4 and IL-10, and the inflammatory infiltrate into the colon was also markedly reduced. RT-PCR assays from colon showed that T. crassiceps-infected mice displayed increased expression of Arginase-1 but decreased expression of iNOS compared to DSS-treated uninfected mice. The percentages of T regulatory cells were not increased. The adoptive transfer of alternatively activated macrophages (AAMФs) from infected mice into mice with DSS-induced colitis reduced the severity of colon inflammation. Administration of indomethacin abrogated the anticolitic effect of Taenia. Thus, T. crassiceps infection limits the pathology of ulcerative colitis by suppressing inflammatory responses mechanistically associated with AAMФs and prostaglandins.
Assuntos
Colite Ulcerativa/parasitologia , Doença de Crohn/parasitologia , Inflamação/parasitologia , Prostaglandinas/biossíntese , Animais , Arginase , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/genética , Doença de Crohn/induzido quimicamente , Doença de Crohn/genética , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Feminino , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Interleucina-10/biossíntese , Interleucina-4/biossíntese , Mucosa Intestinal/parasitologia , Mucosa Intestinal/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Óxido Nítrico Sintase Tipo II/biossíntese , Prostaglandinas/metabolismo , Taenia/patogenicidade , Teníase/complicações , Teníase/parasitologiaRESUMO
Neurocysticercosis in infants and toddlers has received little attention in the literature, and little is known about the mechanisms of disease acquisition and clinical forms of presentation of the disease in this age group. All patients aged ≤3 years with neurocysticercosis evaluated at Hospital-Clínica Kennedy, Guayaquil, over a 22-year period were included in this study. Their household contacts were screened to detect Taenia solium carriers, which may represent the source of infection. A literature search on neurocysticercosis in infants and toddlers was also performed to compare personal cases with those described elsewhere. A total of 25 infants and toddlers with neurocysticercosis were included (seven from our institution and 18 from the literature). All patients had seizures as the primary manifestation of the disease, and neuroimaging studies showed one or two parenchymal brain cysticerci in the colloidal stage in 88% of patients. The source of infection was investigated in 11 houses, including the seven households of the present series, and only four of the 18 reported in the literature. A Taenia carrier was found in five (45%) of these households, including three from the present series and two from the literature. A sizable proportion of infants and toddlers with neurocysticercosis have been infected at home. Compulsory search of Taenia carriers among household contacts will allow the detection of the potential source of infection and will reduce further spread of the disease. The search must not be limited to family members, but also extended to domestic employees who are in daily contact with the children.
Assuntos
Encéfalo/patologia , Neurocisticercose/diagnóstico , Animais , Encéfalo/diagnóstico por imagem , Pré-Escolar , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Humanos , Lactente , Masculino , Neurocisticercose/parasitologia , Exame Neurológico , Estudos Retrospectivos , Taenia/patogenicidade , Tomografia Computadorizada por Raios XRESUMO
Macrophages are critically involved in the interaction between T. crassiceps and the murine host immune system. Also, a strong gender-associated susceptibility to murine cysticercosis has been reported. Here, we examined the sex-associated expression of molecules MHC-II, CD80, CD86, PD-L1, and PD-L2 on peritoneal F4/80(hi) macrophages of BALB/c mice infected with Taenia crassiceps. Peritoneal macrophages from both sexes of mice were exposed to T. crassiceps total extract (TcEx). BALB/c Females mice recruit higher number of macrophages to the peritoneum. Macrophages from infected animals show increased expression of PDL2 and CD80 that was dependent from the sex of the host. These findings suggest that macrophage recruitment at early time points during T. crassiceps infection is a possible mechanism that underlies the differential sex-associated susceptibility displayed by the mouse gender.
Assuntos
Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Antígeno B7-H1/metabolismo , Cisticercose/metabolismo , Antígenos H-2/metabolismo , Macrófagos Peritoneais/metabolismo , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Animais , Antígeno B7-1/imunologia , Antígeno B7-2/imunologia , Cisticercose/imunologia , Cisticercose/parasitologia , Suscetibilidade a Doenças , Feminino , Regulação da Expressão Gênica , Ativação de Macrófagos/imunologia , Macrófagos Peritoneais/imunologia , Masculino , Camundongos , Caracteres Sexuais , Taenia/imunologia , Taenia/metabolismo , Taenia/patogenicidadeRESUMO
OBJECTIVE: Review of human cysticercosis in Canada, to estimate the magnitude of the disease and to describe the pattern of disease expression in this country. METHODS: MEDLINE and manual search of case reports and case series of patients with cysticercosis diagnosed in Canada. Abstracted data included year of diagnosis, citizenship status, clinical manifestations, and form of cysticercosis. FINDINGS: A total of 21 articles reporting 60 patients were found. Forty (67%) of these patients were diagnosed in the past two decades. Most cases came from Ontario (n=43) and Quebec (n=14). Immigrants accounted for 96% of the 28 cases in whom citizenship information was available. Neurocysticercosis was observed in 55 patients, and isolated compromise of striated muscles in the remaining five. Seizures was the primary or sole manifestation of the disease in 72% of patients, and most of them had parenchymal brain cysticerci (either viable cysts or calcifications). Two of seven patients were positive for Taenia eggs. In no case were household contacts of the patients investigated for taeniasis. CONCLUSIONS: An increasing number of patients with cysticercosis have been reported from Canada in the past two decades, suggesting that the prevalence of this parasitic disease may be on the rise. While most cases occur in immigrants, it is possible that at least some of these patients had acquired the disease in Canada.
Assuntos
Cisticercose/epidemiologia , Cisticercose/parasitologia , Taenia/patogenicidade , Animais , Canadá/epidemiologia , Cisticercose/diagnóstico , Humanos , PrevalênciaRESUMO
Information concerning TLR-mediated antigen recognition and regulation of immune responses during helminth infections is scarce. TLR2 is a key molecule required for innate immunity and is involved in the recognition of a wide range of viruses, bacteria, fungi and parasites. Here, we evaluated the role of TLR2 in a Taenia crassiceps cysticercosis model. We compared the course of T. crassiceps infection in C57BL/6 TLR2 knockout mice (TLR2â»/â») with that in wild type C57BL/6 (TLR2âº/âº) mice. In addition, we assessed serum antibody and cytokine profiles, splenic cellular responses and cytokine profiles and the recruitment of alternatively activated macrophages (AAMφs) to the site of the infection. Unlike wild type mice, TLR2â»/â» mice failed to produce significant levels of inflammatory cytokines in either the serum or the spleen during the first two weeks of Taenia infection. TLR2â»/â» mice developed a Th2-dominant immune response, whereas TLR2âº/⺠mice developed a Th1-dominant immune response after Taenia infection. The insufficient production of inflammatory cytokines at early time points and the lack of Th1-dominant adaptive immunity in TLR2â»/â» mice were associated with significantly elevated parasite burdens; in contrast, TLR2âº/⺠mice were resistant to infection. Furthermore, increased recruitment of AAMφs expressing PD-L1, PD-L2, OX40L and mannose receptor was observed in TLR2â»/â» mice. Collectively, these findings indicate that TLR2-dependent signaling pathways are involved in the recognition of T. crassiceps and in the subsequent activation of the innate immune system and production of inflammatory cytokines, which appear to be essential to limit infection during experimental cysticercosis.
Assuntos
Cisticercose/imunologia , Receptor 2 Toll-Like/metabolismo , Animais , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Proliferação de Células , Cisticercose/metabolismo , Cisticercose/parasitologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Receptor de Manose , Lectinas de Ligação a Manose/genética , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante OX40/genética , Ligante OX40/metabolismo , Proteína 2 Ligante de Morte Celular Programada 1/genética , Proteína 2 Ligante de Morte Celular Programada 1/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Taenia/imunologia , Taenia/patogenicidade , Células Th1/imunologia , Células Th2/imunologia , Receptor 2 Toll-Like/genéticaRESUMO
This research was carried out to study the effects of infection with Taenia crassiceps cysticerci on the seminiferous epithelium histoarchitecture in the testes of male mice. Our results showed a severe disruption of the histoarchitecture of the testis epithelium in infected mice. In these animals, a significant infiltration of macrophages within seminiferous tubules was observed (P < 0.001). Generalized apoptosis of germ cells within the seminiferous tubules was observed, as assessed by TUNEL assay and apoptotic nuclei were quantified. The total number of fluorescent objects (DNA) (including clusters, singles, and objects in clusters) was significantly higher in the infected cells than in the control group (P = 0.0286). Observation of the interstitial tissue showed disorder and deterioration of many Leydig cells of infected mice, as well as intense vacuolization and destruction of their inter-cellular junctions. Several ultrastructural abnormalities were observed through electron microscopy as well. The observed pathology could lead to a state of infertility.
Assuntos
Apoptose , Túbulos Seminíferos/patologia , Taenia/patogenicidade , Teníase/patologia , Laranja de Acridina , Animais , Corantes , Modelos Animais de Doenças , Corantes Fluorescentes , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Túbulos Seminíferos/parasitologia , Túbulos Seminíferos/ultraestrutura , Cloreto de TolônioRESUMO
To determine the role of STAT4-dependent Th1 responses in the regulation of immunity to the helminth parasite Taenia crassiceps, we monitored infections with this parasite in resistant mice lacking the STAT4 gene. While T. crassiceps-infected STAT4(+/+) mice rapidly resolved the infection, STAT4(-/-) mice were highly susceptible to infection and displayed large parasite loads. Moreover, the inability of STAT4(-/-) mice to control the infection was associated with the induction of an antigen-specific Th2-type response characterized by significantly higher levels of Th2-associated immunoglobulin G1 (IgG1) and total IgE as well as interleukin-4 (IL-4), IL-10, and IL-13 than those in STAT4(+/+) mice, who produced significantly more gamma interferon. Furthermore, early after infection, macrophages from STAT4(-/-) mice produced lower levels of the pro-inflammatory cytokines IL-12, tumor necrosis factor alpha, IL-1 beta, and nitric oxide (NO) than those from STAT4(+/+) mice, suggesting a pivotal role for macrophages in mediating protection against cysticercosis. These findings demonstrate a critical role for the STAT4 signaling pathway in the development of a Th1-type immune response that is essential for mediating protection against the larval stage of T. crassiceps infection.
Assuntos
Cisticercose/imunologia , Proteínas de Ligação a DNA/metabolismo , Taenia/patogenicidade , Células Th1/imunologia , Transativadores/metabolismo , Animais , Anticorpos Anti-Helmínticos/sangue , Cisticercose/parasitologia , Cysticercus/imunologia , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Ativação Linfocitária , Ativação de Macrófagos , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Receptores CCR5/metabolismo , Receptores de IgE/metabolismo , Fator de Transcrição STAT4 , Taenia/crescimento & desenvolvimento , Transativadores/genéticaRESUMO
Taenia crassiceps can naturally and experimentally infect rodents in which they reproduce by budding. Differences in the susceptibility to T. crassiceps cysticercosis were found between two BALB/c substrains: BALB/cAnN (susceptible) and BALB/cJ (resistant). In chimeric mice, resistance was transferred to susceptible mice with bone marrow cells from the resistant mice, which argues in favor of an immune mediation of the resistant phenotype. To further explore the immune response that could underlie these differences in susceptibility, the specific cellular immune response elicited by the parasite was explored in both substrains. An increased proliferative response and IL-2 levels were induced by cysticercal antigens only in splenocytes from resistant mice. A decrease in the percentage of CD4(+) (11.1%), CD8(+) (17.5%) was found in splenocytes from susceptible BALB/cAnN mice. A study of the TCRV beta repertoire revealed a significant decrease in V beta 2 in both CD4(+) and CD8(+) splenocytes only in the susceptible BALB/cAnN strain.
Assuntos
Cisticercose/imunologia , Taenia/patogenicidade , Animais , Antígenos de Helmintos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Cisticercose/parasitologia , Suscetibilidade a Doenças , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Taenia/imunologiaRESUMO
Taenia crassiceps cysticerci develop in the peritoneal cavity of BALB/cAnN mice and, to a lesser extent, in C57BL/6J mice. The mechanisms involved in the immunity to this murine cysticercosis seem to be mainly mediated by T cells. To gain further insight into the mechanisms of cysticercal immunity, the susceptibility of mice deficient in different immunologically relevant genes was compared with that of the respective wild type. Mice were classified according to the parasite load and survival after infection: highly susceptible (HS), with an increased parasite load and mortality rate (CD4-/-, TCRalpha-/-, TCRbeta-/-, RAG1-/-), susceptible, with only increased parasite load (TCRdelta-/-, BALB/cAnN), and relatively resistant, with a lower number of parasites (CD8-/-, WT). Neither specific proliferative response nor Th2 cytokine or antibody responses were observed in HS mice. These data strongly suggest that CD4+TCRalphabeta+ T cells have a critical role in the control of T. crassiceps murine cysticercosis.