Figure 3. Deletion of the SIRPα cytoplasmic ITIMs in mouse PMNs under inflammatory conditions.

(a) WT mice were induced colitis by feeding with 2% DSS in the drinking water. At different days of the treatment, bone marrow PMNs were isolated from the mice and were analysed for SIRPα by WB using a murine-specific anti-SIRPα.ex (mAb P84) and anti-SIRPα.ct. (b) WB analyses of SIRPα in PMNs obtained from non-DSS-treated mice (CTL) and colitic mice that were treated with 2% DSS for 10 days. The reactivity of anti-SIRPα.ex (mAb P84) versus anti-SIRPα.ct was analysed by densitometry; n = 5 mice per group. The data are presented as means±s.d., *P<0.05 determined by Student’s t-test. (c) The serum levels of the proinflammatory cytokine IL-17 and IL-6 in DSS-treated mice. Note that the loss of SIRPα cytoplasmic ITIMs in PMNs correlated with the high elevation of IL-17, both starting at approximately day 6 during the DSS treatment. (d) WT mice were induced diabetes by STZ administration. Two weeks after the hyperglycaemic conditions were stably established, bone marrow PMNs were analysed for SIRPα by WB. The data are presented as means±s.e.m. (e) Densitometry analyses of SIRPα WB analysis are shown in d. The data are presented as means±s.d., *P<0.05 determined by Student’s t-test. The data are representative of one of five individual experiments. (g) Defects in the recruitment and phosphorylation of SHP-1 in PMN from DSS-treated C57BL/6J WT mice during zymosan–peritonitis. IP, immunoprecipitation; IB, immunoblot.