Treatment with anti-CCL2 antibody alone, or with or without gatifloxacin (GAT) arrests intraocular inflammation and protects retinal function. C57BL/6J mice were intravitreally injected with 100 CFU B. cereus. At 2 hours postinfection, groups of infected eyes were treated with 250 ng/0.5μl anti-CCL2, 1.25ug/0.5μl GAT, 0.5μl PBS containing 250 ng Anti-CCL2 and 1.25μg GAT, and 0.5μg/0.5μl nonspecific isotype IgG2A (Isotype). All eyes were analyzed at 10 hours postinfection. (8A) Gatifloxacin sterilized the eye in both GAT alone and GAT+Anti-CCL2 treated eyes. No differences in bacterial counts were detected between untreated and anti-CCL2 (P=0.0635) or isotype-treated (P=0.7302) eyes. (8B) Retained A-wave function was significantly greater in anti-CCL2 alone (P=0.0087), GAT alone (P=0.0047) and GAT+anti-CCL2 (P=0.0014) treated eyes compared to untreated eyes. (8C) Compared to untreated eyes, B-wave function was not significantly retained in anti-CCL2 alone (P=0.0559), GAT alone (P=0.1471), and GAT+anti-CCL2 (P=0.1088) treated eyes. No differences in A- or B-wave retention was detected between untreated and isotype treated eyes. (8D) Compared to untreated eyes MPO concentrations was significantly less in anti-CCL2 alone (P=0.0159), GAT alone (P=0.0159), and GAT+anti-CCL2 (P=0.0079) treated eyes. Values represent means ± SEM for n ≥ 5 eyes per group per time point with at least 3 independent experiments. *P ≤ 0.05, **P≤0.01, ***P≤0.001, and nsP≥0.05. (8E) H&E staining showed severe inflammation and complete loss of retinal architecture in both untreated and isotype-treated mice. In contrast, mild inflammation and intact retinal layers were found in infected eyes treated with either anti-CCL2 alone, GAT alone, and GAT+anti-CCL2. Original magnification, ×10. Sections are representative of two eyes in each group.