Related Experiment Videos
Cell-mediated immune responses (CMIR) to Rhinosporidium seeberi in mice
S Jayasekera1, S N Arseculeratne, D N Atapattu
1Animal Centre, Medical Research Institute, Colombo, Sri Lanka.
Abstract:
There is no published data on Cell Mediated Immune Responses in experimental animals to Rhinosporidium seeberi the causative agent of human and animal rhinosporidiosis. The quantitative mouse foot-pad model was used to assay the Delayed-Type Hypersensitivity (DTH) cell-mediated immune response to extracts of purified endospores and sporangia of R. seeberi. Histological examination was used to confirm that the foot-pad reactions were compatible with DTH reactions in the mouse. We report that sonically disintegrated rhinosporidial endospores/sporangia induced DTH responses in the foot-pads of sensitized mice which were comparable in intensity and histological profile to that induced by sheep red blood cells in SRBC sensitized mice. Anti-rhinosporidial antibody was also induced. Filtrates of the soluble antigens in sonicated suspensions failed to evoke a DTH-foot-pad (DTH-FP) response in sensitized mice although an anti-rhinosporidial antibody response to this preparation was detected. Prolonged pre-treatment with sonicated suspensions of endospores and sporangia resulted in a decrease of DTH reactivity as compared with reactions following pre-treatment of a shorter duration.
Insights
This study investigated cell-mediated immunity to Rhinosporidium seeberi, the cause of rhinosporidiosis. Researchers found that R. seeberi extracts induced a delayed-type hypersensitivity (DTH) response in mice, similar to other known antigens.
Area of Science:
- Immunology
- Parasitology
- Mycology
Background:
- Rhinosporidiosis is a fungal infection caused by Rhinosporidium seeberi.
- There is a lack of data on cell-mediated immune responses to R. seeberi in experimental models.
- Understanding the immune response is crucial for developing treatments and vaccines.
Purpose of the Study:
- To investigate the cell-mediated immune response to Rhinosporidium seeberi in a mouse model.
- To characterize the delayed-type hypersensitivity (DTH) response induced by R. seeberi antigens.
- To determine the effect of pre-treatment duration on DTH reactivity.
Main Methods:
- Quantitative mouse foot-pad model used to assay DTH response.
- Histological examination to confirm DTH reactions.
- Use of sonically disintegrated endospores and sporangia of R. seeberi as antigens.
- Comparison with sheep red blood cells (SRBC) as a positive control.
Main Results:
- Sonicated R. seeberi endospores/sporangia induced significant DTH responses in sensitized mice.
- The DTH response intensity and histological profile were comparable to SRBC-induced responses.
- Anti-rhinosporidial antibodies were induced.
- Soluble antigens in filtrates failed to elicit a DTH response but induced antibody production.
- Prolonged pre-treatment with R. seeberi antigens decreased DTH reactivity.
Conclusions:
- R. seeberi antigens can induce a DTH cell-mediated immune response in mice.
- Both cellular and humoral immune responses can be generated against R. seeberi.
- The duration of antigen exposure influences DTH reactivity, with prolonged exposure potentially leading to suppression.