Acute respiratory distress syndrome (ARDS) is a common sepsis-associated organ injury and results in significant mortality^1-4; for instance, the LUNG SAFE study reported 34% to 45% mortality.⁵ Despite advances in understanding mechanisms that lead to ARDS,⁶ disease-modifying strategies have not improved outcomes.^7-12 Previous research found that vitamin C attenuates systemic inflammation, corrects sepsis-induced coagulopathy, and attenuates vascular injury.^13-15 The CITRIS-ALI randomized trial examined whether high-dose vitamin C would reduce organ failure and biomarkers of inflammation and vascular injury in patients with sepsis and ARDS.

Purpose Therapeutic outcomes of definitively treated non–small-cell lung cancer (NSCLC) are unacceptably poor. A wealth of preclinical information, and a modest amount of clinical information indicate that dendritic cell (DC) vaccines have therapeutic potential. Only a handful of NSCLC patients have been included in DC clinical trials. We delivered autologous DC vaccines to 16 individuals with stage IA to IIIB NSCLC treated with surgery, chemoradiation, or multimodality therapy. The objectives of the study were to evaluate tolerability and measure immunologic responses to DC vaccines in a heterogeneous group of NSCLC patients. Methods DC vaccines were generated from CD14+ precursors, pulsed with apoptotic bodies of an allogeneic NSCLC cell line that overexpressed Her2/neu, CEA, WT1, Mage2, and survivin. DCs were partially matured with a factor that induced surface molecule expression but minimal cytokine production. Individuals were immunized intradermally two times, 1 month apart. Peripheral blood was drawn serially over 16 weeks, and immune responses were measured by interferon-gamma ELISPOT. Results There were no unanticipated or serious adverse events. Immunologic responses followed three distinct patterns of reactivity: (1) five of 16 patients showed no clear immunologic response, (2) five of 16 patients showed a tumor-antigen independent response, and (3) six of 16 show an antigen specific response. Immunologic responses were independent of stage and prior therapy. Favorable and unfavorable clinical outcomes were independent of measured immunologic responses. Conclusion Vaccines were well tolerated and had biologic activity in a variety of NSCLC patients. Establishing an optimal approach will require comparative studies in well-defined NSCLC patient groups.

Myeloid-derived suppressor cells (MDSCs) are primarily recognized for their immunosuppressive properties in malignant disease. However, their interaction with other innate immune cells and their regulation of immune responses, such as in parasitic infection, necessitate further characterization. We used our previously published mouse model of MDSC accumulation to examine the immunoregulatory role of MDSCs in B16 melanoma metastasis and Nippostrongylus brasiliensis infection. In this study, we demonstrate that the activity of MDSCs is dependent on the immune stimuli and subset induced. Monocytic MDSCs predictably suppressed antitumor immune responses but granulocytic MDSCs surprisingly enhanced the clearance of N. brasiliensis infection. Intriguingly, both results were dependent on MDSC interaction with mast cells (MCs), as demonstrated by adoptive-transfer studies in MC-deficient (KitWsh/Wsh) mice. These findings were further supported by ex vivo cocultures of MCs and MDSCs, indicating a synergistic increase in cytokine production. Thus, MCs can enhance both immunosuppressive and immunosupportive functions of MDSCs.