RESUMO
Gastrointestinal helminthic infection is an important worldwide sheep disease. The emergence of anthelminthic resistance has led to drives to seek new means of therapeutic control of helminthiasis in sheep. Several data demonstrated the adjuvant effect of Propionibacterium acnes on resistance to infection. Herein, we evaluate the adjuvant effect of the commercial suspension containing LPS and P. acnes on experimental helminthiasis. Sheep received three doses of LPS and P. acnes commercial suspension or saline 0.9% (control group). Both groups received orally Haemonchus contortus infective larvae on day 0. Parasitological, haematological, lymphoproliferation analysis, IL-5 and IgE determination were made once a week until 35th day after infection. Our results revealed increase on packed cell volumes on day 14, in LPS + P. acnes treated group. On 21st and 35th days after infection in the same group occurred increase on circulating eosinophils and lymphocytes, and also in the lymphoproliferative response to mitogen. On 35th day, the faecal eggs peak in LPS + P. acnes treated group was significantly lower than control. A negative correlation between faecal eggs counts and circulating eosinophils in the immunostimulant treated group was also observed. Our findings suggest that LPS + P. acnes suspension can be used as a strategy to control helminthiasis in sheep.
Assuntos
Lipopolissacarídeos/imunologia , Infecções por Nematoides/prevenção & controle , Propionibacterium acnes/imunologia , Doenças dos Ovinos/prevenção & controle , Doenças dos Ovinos/parasitologia , Animais , Sangue/parasitologia , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Fezes/parasitologia , Imunoglobulina E/sangue , Interleucina-5/sangue , Linfócitos/imunologia , Masculino , Contagem de Ovos de Parasitas , OvinosRESUMO
Previous reports from our group have demonstrated the association of molecular mimicry between cardiac myosin and the immunodominant Trypanosoma cruzi protein B13 with chronic Chagas´disease cardiomyopathy at both the antibody and heart-infiltrating T cell level. At the peripheral blood level, we observed no difference in primary proliferative responses to T. cruzi B13 protein between chronic Chagas´cardiopathy patients, asymptomatic chagasics and normal individuals. In the present study, we investigated whether T cells sensitized by T. cruzi B13 protein respond to cardiac myosin. T cell clones generated from a B13-stimulated T cell line obtained from peripheral blood of a B13-responsive normal donor were tested for proliferation against B13 protein and human cardiac myosin. The results showed that one clone responded to B13 protein alone and the clone FA46, displaying the highest stimulation index to B13 protein (SI=25.7), also recognized cardiac myosin. These data show that B13 and cardiac myosin share epitopes at the T cell level and that sensitization of a T cell with B13 protein results in response to cardiac myosin. It can be hypothesized that this also occurs in vivo during T. cruzi infection which results in heart tissue damage in chronic Chagas´disease cardiomyopathy.