B6.129p cx3cr1tm1litt j mice

Female wild type C57BL/6 J mice (denoted CX₃CR1^+/+ mice, n = 34), 8 weeks of age, were obtained via Charles River Laboratories (L'Arbresle Cedex, France) (strain code 027). Female B6.129P-Cx3cr1^tm1Litt/J mice (denoted CX₃CR1^−/− mice, n = 33) were obtained via Jackson Laboratories (Bar Harbor, Maine, USA) (strain code 5582) and further bred in the specific pathogen free facility of the University of Antwerp. According to the information available upon purchase, the donating investigator has reported to Jackson Laboratories that original CX₃CR1^+/− chimeric animals were backcrossed to C57BL/6 background for 10 generations before being made homozygous. Female B6.129P-Cx3cr1^tm1Litt/J mice were mated with male wild type C57BL/6 J mice and female offspring were used (denoted CX₃CR1^+/− mice, n = 15). For all experiments, mice were kept in a normal day–night cycle (12/12) with free access to food and water. For induction of CNS inflammation and demyelination, CX₃CR1^+/+, CX₃CR1^+/− and CX₃CR1^−/− mice received standard rodent chow mixed with 0.2% w/w CPZ (Sigma-Aldrich, Diegem, Belgium) for 4 weeks between the ages of 8 and 12 weeks. All experimental procedures were performed in accordance with European guidelines (2010/63/EU) and were approved by the Ethics Committee for Animal Experiments of the University of Antwerp (approval nos 2011/13 and 2013/57).

CD18 hypomorphic mutant mice (B6.129S7-Itgb2^tm1Bay/J mice; Jackson Laboratories)^{56 (link)}, heterozygous Cx3cr1^GFP/+ mice (B6.129P-Cx3cr1^tm1Litt/J mice; Jackson Laboratories)^{57 (link)}, and P2RX₇ KO mice (B6.129P2-P2rx7^tm1Gab/J; Jackson Laboratories)^{22 (link)} were used in this study. Wild-type C57BL/6J mice or littermate mice were used as controls. Mice (2-3 months old, 22-25 g) were group housed on a 12-h light/dark cycle at a constant temperature of 22 ± 1 °C with 40-60% humidity. All animal studies were approved by the Committees for Animal Experiments of Zhejiang University in China and conformed to NIH guidelines (Guide for the Care and Use of Laboratory Animals. NIH publication no. 85-23, revised 1996).