FIG 6.
Targeted depletion of erythrocytes from the spleen increases host susceptibility to Salmonella. C57BL/6 mice were infected i.v. with 5 × 105 CFU of an attenuated Salmonella strain (BRD509). Cohorts of mice were treated with high-affinity SIRPα variants (CV1) on day 3 and day 6 after infection. (A) Percentages and total cell numbers of RBCs (Ter119+ CD71−), reticulocytes (Ter119+ CD71+), and proerythroblasts (Ter119med CD71+) in the spleens of naive, Salmonella-infected, and Salmonella-infected and CV1-treated mice as measured by flow cytometry. (B) Bacterial counts in the spleens and livers of Salmonella-infected mice at 7 days postinfection with or without CV1 treatment. (C) Blood EPO levels in naive, Salmonella-infected, and Salmonella-infected and CV1-treated mice as measured by an ELISA. An unpaired t test was used to calculate statistical significance for panels A to C. Error bars represent the means ± standard errors of the means. *, P < 0.05; **, P < 0.01; n.d., not detected.