Figure 4.
Figure 4. Recovery of innate immune protection from acute infection after BMT and how it relates to TE and BE. (A) This plot shows the mean number of E-GFP neutrophils (expressed as percentage of recipient control) in lung lavage samples from mice infected on days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, BAL fluid is collected, and the concentration of neutrophils present in BAL fluid samples is determined by using differential cytology (counting a total of 200 cells per slide). Mice infected 1 month after BMT experienced a significantly greater pulmonary recruitment of neutrophils following infection than all other groups of mice, including day 1 (P < .001), day 2 (P < .001), day 3 (P < .001), day 4 (P < .01), and day 5 (P < .005) after BMT. These results demonstrate that neutrophil levels recruited to a site of infection increase significantly from day to day as mice recover from BMT to resemble more and more the values found in their healthy donors (donor control, no BMT) than their own control values (recipient control, no BMT), before BMT treatment. Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (B) This chart shows the mean bacterial survival (expressed as percentage of recipient control) in lung lavage samples from mice infected on days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, BAL fluid is analyzed for bacterial persistence. Serial 10-fold dilutions of BAL fluid are plated on LB agar plates. The number of viable CFUs of PAOI is determined after 24 hours of incubation at 37°C. Lung lavages taken from mice infected 1 month after BMT exhibited significantly greater bacterial killing than mice infected on day 1 (P < .001), day 2 (P < .05), and day 3 (P < .005) after BMT. However, mice similarly infected on day 4 or TE day (P > .1) and day 5 or after TE and before BE day (P > .1) had similar levels of bacterial killing as did mice infected 1 month after BMT. Additionally, lung lavages taken from mice infected on day 4 (TE day) exhibited significantly greater bacterial killing than mice infected on day 1(P < .001), day 2 (P < .05), and day 3 (P < .01). Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (C) This plot shows the mean bacterial survival (expressed as percentage of recipient control) in lung homogenate samples from mice infected on different days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, lungs are collected and homogenized in 2 mL PBS using a tissue homogenizer (Brinkman Instruments). Serial 10-fold dilutions of lung homogenates are plated on LB agar plates. The number of viable CFUs of PAOI is determined after a 24-hour incubation at 37°C. The lavage results were confirmed by using the lung homogenates of the infected mice. No significant differences were observed between the amount of bacterial survival in the lungs of mice infected on day 4 (P > .5) or day 5 (P > .1) after BMT when compared with those of mice infected 1 month after BMT and long after blood confirmed engraftment. However, a significant decrease in bacterial persistence was observed in mice infected 1 month after BMT when compared with mice infectedonday1(P < .001), day2(P < .001), and day 3 (P < .005) after BMT. Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (D) Light micrographs of lung lavage fluid cytospin preparations. These preparations were stained using the Wright-Giemsa method showing (left) neutrophils found in BAL fluid of a mouse infected 1 month after BMT and (right) a fluorescent micrograph of neutrophils found in BAL fluid of the same mouse. Original magnification, × 40.

Recovery of innate immune protection from acute infection after BMT and how it relates to TE and BE. (A) This plot shows the mean number of E-GFP neutrophils (expressed as percentage of recipient control) in lung lavage samples from mice infected on days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, BAL fluid is collected, and the concentration of neutrophils present in BAL fluid samples is determined by using differential cytology (counting a total of 200 cells per slide). Mice infected 1 month after BMT experienced a significantly greater pulmonary recruitment of neutrophils following infection than all other groups of mice, including day 1 (P < .001), day 2 (P < .001), day 3 (P < .001), day 4 (P < .01), and day 5 (P < .005) after BMT. These results demonstrate that neutrophil levels recruited to a site of infection increase significantly from day to day as mice recover from BMT to resemble more and more the values found in their healthy donors (donor control, no BMT) than their own control values (recipient control, no BMT), before BMT treatment. Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (B) This chart shows the mean bacterial survival (expressed as percentage of recipient control) in lung lavage samples from mice infected on days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, BAL fluid is analyzed for bacterial persistence. Serial 10-fold dilutions of BAL fluid are plated on LB agar plates. The number of viable CFUs of PAOI is determined after 24 hours of incubation at 37°C. Lung lavages taken from mice infected 1 month after BMT exhibited significantly greater bacterial killing than mice infected on day 1 (P < .001), day 2 (P < .05), and day 3 (P < .005) after BMT. However, mice similarly infected on day 4 or TE day (P > .1) and day 5 or after TE and before BE day (P > .1) had similar levels of bacterial killing as did mice infected 1 month after BMT. Additionally, lung lavages taken from mice infected on day 4 (TE day) exhibited significantly greater bacterial killing than mice infected on day 1(P < .001), day 2 (P < .05), and day 3 (P < .01). Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (C) This plot shows the mean bacterial survival (expressed as percentage of recipient control) in lung homogenate samples from mice infected on different days before and after tissue (TE) and blood (BE) engraftment and after BMT. Following a 4-hour period of acute infection, lungs are collected and homogenized in 2 mL PBS using a tissue homogenizer (Brinkman Instruments). Serial 10-fold dilutions of lung homogenates are plated on LB agar plates. The number of viable CFUs of PAOI is determined after a 24-hour incubation at 37°C. The lavage results were confirmed by using the lung homogenates of the infected mice. No significant differences were observed between the amount of bacterial survival in the lungs of mice infected on day 4 (P > .5) or day 5 (P > .1) after BMT when compared with those of mice infected 1 month after BMT and long after blood confirmed engraftment. However, a significant decrease in bacterial persistence was observed in mice infected 1 month after BMT when compared with mice infectedonday1(P < .001), day2(P < .001), and day 3 (P < .005) after BMT. Three to 10 mice were tested for days 1 through 5 after BMT and for 1 month after BMT. Mean ± SD was calculated. (D) Light micrographs of lung lavage fluid cytospin preparations. These preparations were stained using the Wright-Giemsa method showing (left) neutrophils found in BAL fluid of a mouse infected 1 month after BMT and (right) a fluorescent micrograph of neutrophils found in BAL fluid of the same mouse. Original magnification, × 40.

Close Modal
This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal