Dr. Cross has three major areas of interest: the development of a vaccine for the prevention and treatment of sepsis; the early interactions of B. anthracis (BA) with the host immune system and the role of sialic acid in innate and adaptive immunity. A previous phase I study with a detoxified endotoxin vaccine complexed to group B meningococcal outer membrane protein revealed that while the vaccine was well-tolerated, it was only weakly immunogenic. Currently, preclinical studies in murine models as well as clinical studies in human subjects are continuing with this vaccine given in conjunction with novel adjuvants. Dr. Cross's work with B. anthracis is now focused on the mechanisms by which this pathogen is killed by myeloid cells and how it initiates an adaptive immune response. He is characterizing the role of the various BA structures (spore and vegetative forms and exosporium) to modulate the host response and assessing the effect of anthrax toxins on myeloid function. Finally, he found that the sialidase (neuraminidase) activity of various cells in the immune system is an essential element of innate and adaptive immunity. Currently Dr. Cross's laboratory is focusing on the mechanisms by which human neutrophil sialidase regulates cellular trafficking in both in vivo and in vitro model systems. These studies rely on endothelial cell culture systems as well as murine models of inflammation.