Abstract
Purpose::
Toxoplasma gondii is a major cause of infectious retinitis throughout the world. Little is known about mechanisms of resistance against ocular toxoplasmosis. Retinal pigmented epithelial (RPE) cells appear to be a major target of infection in toxoplasmic retinochoroiditis. CD40 induces anti-microbial activity in macrophages. Primary RPE express CD40. Thus, we hypothesized that CD40 induces toxoplasmacidal activity in RPE.
Methods::
An RPE cell line was transduced with a retroviral vector that endoces witd-type CD40 and EGFP or an empty vector. RPE cells were then stimulated with recombinant CD154 and TNF-alpha and infected with tachyzoites of T. gondii.
Results::
RPE cells tranduced with the CD40-encoding retroviral vector expressed functional CD40 since stimulation with CD154 caused marked upregulation of ICAM-1. In contrast to RPE cells tranduced with the empty retroviral vector, RPE cells transduced with CD40-encoding vector acquired anti-T. gondii activity in response to CD40 stimulation plus TNF-alpha
Conclusions::
CD40 triggers anti-microbial activity in RPE cells.
Keywords: retinal pigment epithelium • retinitis