1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests \> 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests \> 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). patients who have been intubated. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. patients with untreated human immunodeficiency virus (hiv) infection. creatinine clearance less than 30 ml/minute. liver function tests > 5x normal. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. treatment with a cell therapy product within 12 months prior to randomization. participation in an ongoing protocol studying an experimental drug or device. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). patients who have been intubated. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. patients with untreated human immunodeficiency virus (hiv) infection. creatinine clearance less than 30 ml/minute. liver function tests > 5x normal. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. treatment with a cell therapy product within 12 months prior to randomization. participation in an ongoing protocol studying an experimental drug or device. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests > 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests > 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated for more than 1 week. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests > 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.

1. currently receiving extracorporeal membrane oxygenation (ecmo) or high frequency oscillatory ventilation (hfov). 2. patients who have been intubated for more than 1 week. 3. patients with established positive bacterial blood cultures prior to enrollment or suspicion of superimposed bacterial pneumonia. 4. patients with untreated human immunodeficiency virus (hiv) infection. 5. creatinine clearance less than 30 ml/minute. 6. liver function tests > 5x normal. 7. current or history (within the previous 5 years) of systemic autoimmune or connective tissue disease. 8. known allergy or hypersensitivity to any of the ip constituents such as dimethyl sulfoxide (dmso) or bovine proteins. 9. treatment with a cell therapy product within 12 months prior to randomization. 10. participation in an ongoing protocol studying an experimental drug or device. 11. pregnant or breastfeeding female subjects, and sexually active female subjects of childbearing potential not willing to use contraceptive methods.