Evaluating the Immune Response to the Artificial Oxygen Carrier OxyVita® 2308574

Abstract Introduction A major challenge in treating uncontrolled blood loss through hemorrhage is the lack of an oxygen delivery system to support vital organs when whole blood is unavailable. OxyVita is a polymerized stroma-free bovine hemoglobin-based oxygen carrier (HBOC) that was developed by OXYVITA Inc. to deliver oxygen in emergency medical situations. The current study examines the immunological consequences of exposure to OxyVita both in mice and in cell culture. Methods We immunized BALB/c mice with OxyVita or saline either in the peritoneal cavity (IP) or in the tail vein (IV) two to three times. Collected blood sera were evaluated for the presence of antibodies reactive to the OxyVita polymer by ELISA. We further evaluated the ability of OxyVita to stimulate the RAW 264.7 macrophage cell line to secrete various cytokines in vitro by ELISA. Results OxyVita immunization stimulated high concentrations of circulating antibodies in mice after a single exposure via both the IP and IV routes. These concentrations increased with subsequent exposures demonstrating immunological memory responses. Importantly, the mice appeared to remain in good health throughout the experiment and immunized and non-immunized animals gained weight at similar rates. OxyVita stimulated RAW 264.7 cells to secrete the inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) as well as the anti-inflammatory cytokine interleukin-10. Conclusion These results suggest that the OxyVita polymer has the potential to stimulate both the innate and adaptive immune responses in vivo and in vitro, however, there may be a balance struck between the pro- and anti-inflammatory signals elicited. The lack of obvious pathology in mice following multiple exposures provides encouraging support for continued preclinical studies with this novel HBOC. Funding Source College departmental research budget less than $1000 per year Topic Categories Translational and Interventional Immunology (TI)