Furthermore, S1pr5−/− mice constitute an interesting model to study the role of Ly6C− monocytes in immunity, a point that remains unclear. WT C57BL/6 mice were purchased from Charles River Laboratories (L’Arbresle, France). S1pr5−/− mice [18], Ccr2−/− [30], and Cx3cr1gfp/gfp mice [31] have been previously described. In
some experiments, we also used C57BL/6 CD45.1 mice or C57BL/6 CD45.1 × CD45.2 mice that were bred in our animal house. Female mice 8–24 week-old were used unless specified. DOP (Sigma, St. Louis, MO, USA) was provided in the drinking water (30 μg/mL) supplemented with glucose. Experimental procedures and mice housing were approved by the local Ethics Committee and carried out according to the French and European laws. C57BL/6 CD45.1 × CD45.2 mice were irradiated twice INK 128 in vitro at 450 rad within a 4-h interval. Four hours PCI-32765 solubility dmso after the last irradiation, they received an intravenous injection of a 1:1 mixture of BM cells from WT CD45.1 and S1pr5−/− CD45.2 mice. BM chimeras were analyzed 6–12 weeks after reconstitution. This technique was previously described [32]. Briefly, mice were injected intravenously with 1 μg anti-CD45 Mab (30F11) coupled to phycoerythrin (PE) or PE-cyanin-5 (BD Biosciences, San Jose, USA). Mice were sacrificed 2 min after antibody injection. BM was
then collected and analyzed by flow cytometry. BM cells from WT CD45.1 and S1pr5−/− or Cx3cr1gfp/gfp (CD45.2) mice were prepared and mixed at a 1:1 ratio before intravenous injection (1 × 107 cells of each genotype in PBS) into anesthetized CD45.1 × CD45.2 C57BL/6 mice. Sixteen hours later, mice were sacrificed, blood and bone marrow was collected and the percentage of monocyte subsets of each
donor mice was measured by flow cytometry after staining for CD45.1 and CD45.2 expression. Cell viability was measured in ex vivo isolated cell suspensions using Annexin V and 7-AAD staining (BD Biosciences) and flow cytometry. BM, spleen, lung, lymph node, kidney, and blood cells were isolated and stained as previously described [33]. Cell counts were determined using an accuri C6 flow cytometer (BD Accuri Cytometers, Ann Arbor, MI, USA). Monocytes were identified as CD115+ in the see more blood or as CD11b+CD11clowNK1.1−CD19−Ly6G− in the BM and spleen. The following Mabs from eBioscience (San Diego, CA, USA) or BD Biosciences (Becton Dickinson, San Jose, USA) were used: anti-CD115 (AFS98), anti-Ly6C (HK1.4), anti-Ly6G (1A8), anti-CD19 (ebio1D3), anti-CD3 (145–2C11), anti-NK1.1 (PK136), anti NKp46 (29A1.4), anti-CD11b (M1/70), anti-CD45.1 (A20), anti CD45.2 (104), and relevant isotype controls. Bcl2 expression was measured using a commercial kit (BD Biosciences) according to the manufacturer’s instructions. Flow cytometry was carried out on a FACS Canto, a FACS Canto II or a FACS LSR II (Becton Dickinson). For S1P migration assays, monocytes were purified from BM cells using a negative selection procedure.