Figure 4.

NP Transplant Improves Neutrophil Recruitment and Bacterial Clearance without Worsening Acute Lung Injury

S. aureus pneumonia was induced 48 h after hemorrhagic shock or sham hemorrhage, with or without adoptive transfer of NPs.

(A) The total number of neutrophils recruited to the alveolae were quantified by flow cytometry analysis of BAL fluid (n = 5 mice per condition) 24 h after infection. Neutrophils were identified by Ly6G expression.

(B) Twenty-four hours post infection with S. aureus, the degree of bacterial burden in the lung homogenate was measured by plating serial dilutions of digested lung in triplicate. Data are expressed as mean CFUs ± SEM (n = 6 mice per condition). Mice that did not receive S. aureus did not have detectable CFUs and were used to confirm specificity of the assay. CFU data were taken from distinct samples.

(C) The albumin content of the BAL fluid was measured by ELISA 24 h post infection (n = 5 mice per condition). BAL neutrophils and albumin represent a repeated measure of the same sample. Data are expressed as mean albumin content ±SEM.

(D) Representative images of lung sections stained with hematoxylin and eosin. Images were captured and selected by a blinded observer. Scale bar is equal to 100 μm. Data were acquired across three independent experiments (n = 3 mice per condition). Histologic data were acquired from distinct samples. Data were fit to a lognormal distribution, analyzed by GLMs, and the Holms test was used to adjust for multiple comparisons. ^∗p < 0.05, ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001.