Quantitative PCR confirmed upregulation of CXCL1, CXCL2, CXCL10, CCL2, CCL3, and IL-6 in wild type C57BL6/J mouse retinas following infection relative to uninfected mouse eyes, but no changes in expression in any of these genes in TLR4−/− mouse retinas 4 h after infection were observed, including CCL3 (Table 2, primer sequences are shown in Additional file 1: Table S2). Here, CCL3 is linked to infection.