Depletion of CD8+ T Cells In Vivo Impairs Host Defense of Mice Resistant and Susceptible to Pulmonary Paracoccidioidomycosis

AUTOR(ES)

Cano, Luz E.

FONTE

American Society for Microbiology

RESUMO

Using a pulmonary model of infection, we demonstrated previously that A/Sn and B10.A mice are, respectively, resistant and susceptible to Paracoccidioides brasiliensis infection. Employing the same experimental model, we examined herein the role of CD8+ T cells in the course of paracoccidioidomycosis. Treatment with anti-CD8 monoclonal antibodies caused a selective depletion of pulmonary and splenic CD8+ T cells in both mouse strains. The number of pulmonary CD4+ T cells and immunoglobulin-positive cells was independent of the number of CD8+ T cells. In susceptible mice, the loss of CD8+ T cells by in vivo treatment with anti-CD8 monoclonal antibodies impaired the clearance of yeasts from the lungs and increased the fungal dissemination to the liver and spleen. The same treatment in resistant mice increased fungal dissemination to extrapulmonary tissues but did not alter the pulmonary fungal load. Furthermore, CD8+ T-cell depletion did not modify delayed-type hypersensitivity reactions of A/Sn mice but increased these reactions in B10.A mice. The production of P. brasiliensis-specific antibodies by resistant and susceptible mice depleted of CD8+ T cells was similar to that of mice given control antibody. Histopathologically, depletion of CD8+ T cells did not disorganize the focal granulomatous lesions developed by both mouse strains. These results indicate that CD8+ T cells are necessary for optimal clearance of the fungus from tissues of mice infected with P. brasiliensis and demonstrate more prominent protective activity by those cells in the immune responses mounted by susceptible animals.

Documentos Relacionados

• In vivo depletion of CD8+ T cells prevents lesions of demyelination in Semliki Forest virus infection.
• Resolution of Secondary Chlamydia trachomatis Genital Tract Infection in Immune Mice with Depletion of Both CD4+ and CD8+ T cells
• Preterminal host dendritic cells in irradiated mice prime CD8+ T cell–mediated acute graft-versus-host disease
• CD4+ and CD8+ T-cell-dependent and -independent host defense mechanisms can operate to control and resolve primary and secondary Francisella tularensis LVS infection in mice.
• In vivo proliferation of naïve and memory influenza-specific CD8+ T cells