Chronic infection and reactivation in a pulmonary challenge model of histoplasmosis

J Infect Dis. 2001 Jun 15;183(12):1822-4. doi: 10.1086/320720. Epub 2001 May 16.

Abstract

Reactivation may be a mechanism for the development of histoplasmosis in AIDS. In this study, histoplasmosis was reactivated by the depletion of CD4 and CD8 lymphocytes in mice. CD4 and/or CD8 depletion beginning 1 month after intratracheal infection and continuing for 2 months caused reactivation with a 2.1 log/g increase in the lungs and a 1.5 log increase in the spleen of B6C3F1 mice. Because control animals showed persistent infection, a subsequent experiment sought to determine the long-term outcome in competent mice. Twelve of 32 immunocompetent mice died at weeks 26-52 of infection, and 4 survivors appeared to be clinically ill; all ill mice had high fungus burdens, whereas cultures were sterile in the healthy mice. Eight of the surviving healthy-appearing mice underwent autopsy 2 years after infection, and cultures were sterile. Thus, 16 of 32 immunocompetent mice exhibited progressive infection. CD4 and/or CD8 depletion exacerbated infection, but a chronic progressive and ultimately fatal infection occurred in half the immunocompetent mice.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Disease Models, Animal*
  • Female
  • HIV Infections / complications
  • HIV Infections / immunology
  • Histoplasmosis / immunology*
  • Immunocompetence
  • Immunocompromised Host / immunology*
  • Mice
  • Random Allocation
  • Recurrence
  • Survivors