Figure 9. Lyn, AKT and MKP-1 are involved in CR3-mediated immune suppression during Schu S4 phagocytosis by macrophages.

(A) hMDMs were transfected with control siRNA or siRNA targeting CD11b or TLR2. 48 h later cells were infected with non-opsonized or serum pre-opsonized Ft Schu S4 in the absence of serum for 30 min at MOI of 50. Infections were synchronized as described in the materials and methods. Cell lysates were subjected to SDS-PAGE and Western blot using antibodies against phospho-Lyn (Y396), phospho-Akt (T308), MKP-1 or β-actin. (B) Lyn siRNA knockdown in hMDMs. hMDMs were transfected with control siRNA or siRNAs targeting Lyn. 48 hrs later cell lysates were subjected Western blot using an antibody against Lyn. (C) 48 h after scrambled or Lyn siRNA transfection hMDMs were infected with Schu S4 in the presence or absence of serum at an MOI of 50∶1. 16 h post infection TNFα, IL-6 and IL-1β levels in culture supernatants were measured by ELISA. Data are representative of 3 independent experiments, each performed in triplicate. The data were analyzed by a two-tailed Student t-test *** p<0.001.