Abstract
Abstract: :
Purpose: To investigate changes in immunomodulatory genes following T.gondii infection of Müller cells. Methods: Human Müller cells (MIO–M1 a kind gift of Dr. Limb, Institute of Ophthalmology, UK) were infected or mock infected with the two strains of T.gondii (RH and Prugniaud). RNA and supernatants were collected from infected and uninfected cells at two and twenty four hours. RNA from infected and uninfected cells from the two time points were compared using a custom made DNA microarray (Birmingham, UK). Real time PCR or human cytokine antibody array was used to confirm these changes. Results: We found upregulation of MCP–1, IL–6, IL–8, and GROß by microarray after infection with both strains. MCP–1 and GROß upregulation was confirmed by Real Time PCR. Following infection with the Prugniaud strain, which did encyst within Müller cells, IL–4 and IL–6 protein levels were greater after 2 hours and 24 hours (p≤0.05 and p≤0.01 respectively) and IL–8 production was greater at 24 hours (p≤0.05). By contrast, IL–4 and IL–8 levels were only raised at 24 hours following infection with the RH strain (p≤0.05). However we did not find upregulation of IFNγ, TNFα, IL–10, IL–12 and NF–ΚB. Conclusions: T.gondii infection of Müller cells elicits upregulation of IL–4, IL–6, IL–8, MCP–1 and GROß. The production of the chemokines IL–8, MCP–1 and GROß plays an important role in recruiting cells to clear infection. The cytokines IL–4 and IL–6 may play a role in the promotion and maintenance of parasite encystment since lack of IL–6 exacerbates chronic ocular toxoplasmosis (Infect & Immun 69:2589, 2001) and an absence of IL–4 promotes susceptibility to toxoplasmic encephalitis (J. Immunol 157:2564, 1996).
Keywords: toxoplasmosis • gene microarray • Muller cells