Experimental paracoccidioidomycosis in high and low antibody responder mice of Selection IV-A

Date
2000-08-01Author
Soares, Angela Maria Victoriano de Campos
Rezkallah-Iwasso, Maria Thereza
Oliveira, S. L.
Peraçoli, Maria Terezinha Serrão
Montenegro, Mário Rubens Guimarães
Musatti, Chloe Camba [UNIFESP]
Type
ArtigoISSN
1369-3786Is part of
Medical MycologyMetadata
Show full item recordAbstract
High (H) and low (L) responder mice were selected for their ability to produce antibodies against sheep and human erythrocytes (Selection IV-A). In this selection, the difference in antibody responsiveness between H and L lines (HIV-A and LIV-A mice, respectively) was shown to depend mainly on macrophage function. The more rapid catabolism of antigens by macrophages in L mice has been suggested as the main cause of the low antibody production. Due to this high macrophage activity, L animals have been described as more resistant than H animals to intracellular pathogens. These animals were utilized as an experimental model of paracoccidioidomycosis. HIV-A and LIV-A mice were infected with Paracoccidioides brasiliensis by the intravenous route. As expected, H mice were more susceptible to P. brasiliensis with a shorter survival time and higher levels of specific antibodies when compared to L mice. Contrasting with the survival time, the lungs, spleen and liver from H mice showed typical nodular granulomas containing epithelioid and giant cells and few fungi. On the other hand, in LN-A mice, the lesions of these organs were characterized by looser granulomas with irregular borders and the presence of a large number of fungi, However, the adrenal gland showed different lesion patterns. In H mice these lesions were extensive and characterized by loose granulomas with numerous fungi, while in LIV-A mice the lesions were small and limited to the cortex. Moreover the HIV-A mice presented higher levels of serum corticosterone when compared to LIV-A ones. The higher susceptibility of H mice could be attributed to the extensive lesions of the adrenal glands. These results suggest the use of the H line from the IV-A Selection as an experimental model for further studies of adrenal involvement in paracoccidioidomycosis.
Citation
Medical Mycology. Oxford: B I O S Scientific Publishers Ltd, v. 38, n. 4, p. 309-315, 2000.Collections
- EPM - Artigos [17701]