RESUMO
In chickens, the nematode Ascaridia galli is found with prevalences of up to 100% causing economic losses to farmers. No avian nematode vaccines have yet been developed and detailed knowledge about the chicken immune response towards A. galli is therefore of great importance. The objective of this study was to evaluate the induction of protective immune responses to A. galli soluble antigen by different immunization routes. Chickens were immunized with a crude extract of A. galli via an oral or intra-muscular route using cholera toxin B subunit as adjuvant and subsequently challenged with A. galli. Only chickens immunized via the intra-muscular route developed a specific A. galli antibody response. Frequencies of γδ T cells in spleen were higher 7 days after the first immunization in both groups but only significantly so in the intra-muscularly immunized group. In addition, systemic immunization had an effect on both Th1 and Th2 cytokines in caecal tonsils and Meckel's diverticulum. Thus both humoral and cellular immune responses are inducible by soluble A. galli antigen, but in this study no protection against the parasite was achieved.
Assuntos
Ascaridia/imunologia , Ascaridíase/veterinária , Galinhas , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/parasitologia , Vacinas Protozoárias/imunologia , Administração Oral , Animais , Ascaridíase/prevenção & controle , Toxina da Cólera/imunologia , Primers do DNA/genética , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Citometria de Fluxo/veterinária , Injeções Intramusculares/veterinária , Modelos Lineares , Masculino , Vacinas Protozoárias/administração & dosagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Linfócitos T/imunologiaRESUMO
Dopamine, a catecholamine neurotransmitter, is important for insect development and is known to be involved in insect stress responses. In the current study, dopamine was analysed in Aedes aegypti heads by HPLC. We found that immediately after adult emergence, males have significantly higher concentrations of dopamine than females, and that dopamine concentrations decrease with age in both sexes. Dopamine levels increase in females following a blood meal suggesting that dopamine might be involved in ovarian- and/or egg-development. We also found that female mosquitoes have a higher tolerance to a short term thermal stress in a water bath than males up to 44 degrees C, however, both sexes die if exposed to short term temperatures between 44 and 45 degrees C. Finally, we did not find any indication that dopamine levels were associated with short time thermal stress response in female mosquitoes.