In 2000, he joined the University of Maryland as Professor of Cell Biology and Molecular Genetics.
[5] He was the Chair of Division E (Immunology) of the ASM (2012)[6] and a member of the NIH, NIAID Board of Scientific Councilors (2005-2010).
He continues to serve on the Editorial Boards of mBio (since 2010),[7] Frontiers in Immunology (since 2010),[8] and of Microbiology Spectrum (since 2014).
[10] Mosser's laboratory has studied the heterogeneity of macrophages, and the roles these cells play in positively or negatively influencing adaptive immune responses.
[12] Macrophages are secretory cells, and the cytokines they produce play an important role in modifying innate and adaptive immune responses.
Mosser and his colleagues have examined cytokine production by macrophages and have characterized the transcription factors and signaling pathways involved in cytokine production by differentially stimulated macrophages.