Expression analysis of immune response genes of Muller cells infeted with Toxoplasma gondi

Purpose: To investigate changes in immune response genes following Toxoplasma gondii infection of Muller cells. Methods: Human Muller cells were infected or mock infected with two strains of T. gondii (RH and Prugniaud). RNA and supernatants were collected from infected and uninfected cells at 2 and 24 h. RNA from the two time points were compared using a custom made DNA microarray. Real time PCR or human cytokine antibody array was used to confirm up-regulation of immune molecules. Results: Gene expression in infected cells showed up-regulation of CCL2, IL-6, CXCL8, and CXCL2. CCL2 and CXCL2 gene expression was confirmed by real time PCR. IL-6 and CXCL8 protein production was confirmed by a cytokine antibody array. IL-4 production was observed by cytokine antibody array but not by DNA microarray. In contrast, infection with T. gondii did not induce interferon-gamma (IFN gamma) and IL-12 expression, molecules conventionally associated with the inter-conversion of tachyzoite to bradyzoite. Conclusion: These results indicate that while in vitro infected Muller cells may be capable of inducing an immune response by attracting blood-borne leucocytes, they do not appear able to directly control the proliferation of T. gondii. (c) 2006 Elsevier B.V. All rights reserved.