RESUMO
When mice were immunized intravenously, subcutaneously, or by the footpad route with formaldehyde-killed Trypanosoma rhodesiense, delayed-type hypersensitivity was elicited by the use of frozen-thawed trypanosomal antigen. The delayed footpad swelling technique was used to measure delayed hypersensitivity. Hypersensitivity induction was dose dependent (greater than or equal to 10(6) formaldehyde-treated T. rhodesiense) and was affected by the route of immunization. The footpad route induced higher levels of hypersensitivity than other routes of immunization. Mice immunized with a single dose of formaldehyde-treated antigen and challenged with live T. rhodesiense did not survive. Yet, mice immunized subcutaneously with formaldehyde-treated antigen and then injected with frozen-thawed antigen and challenged 28 days after immunization survived. The results suggest that T-cell activation, manifested by delayed hypersensitivity responses, was a necessary component in the protective response, perhaps functioning in a helper cell capacity.
Assuntos
Hipersensibilidade Tardia/imunologia , Imunidade Celular , Trypanosoma brucei brucei/imunologia , Animais , Antígenos/administração & dosagem , Relação Dose-Resposta Imunológica , Feminino , Imunização , Camundongos , RatosRESUMO
Mice were immunized subcutaneously, intravenously or in a footpad with antigens prepared from a lethal strain of Plasmodium berghei yoelii. A delayed footpad swelling (DFS) reaction was observed 4 days after immunization, and was detectable at least 42 days after immunization. However, IV immunization was the least efficacious is producing hypersensitivity. Regardless of the type of antigen used for immunization, mice responded similarly when live parasites were used to elicit DFS. This study revealed that hypersensitivity depended on route of immunization and type of antigen.
Assuntos
Antígenos , Hipersensibilidade Tardia , Imunização/métodos , Malária/imunologia , Plasmodium berghei/imunologia , Animais , Antígenos/administração & dosagem , Feminino , Injeções Intramusculares , Injeções Intravenosas , Injeções Subcutâneas , CamundongosRESUMO
Mice pretreated with cyclophosphamide were able to overcome infection from a lethal malarial strain. The development of resistance was preceded by increased hypersensitivity to malarial antigens. Hypersensitivity was demonstrable by a delayed footpad swelling technique.
