David Mosser

Mosser's laboratory has studied the heterogeneity of macrophages, and the roles these cells play in positively or negatively influencing adaptive immune responses. Mosser is generally credited with identifying and characterizing a population of macrophages with anti-inflammatory and immunoregulatory activity, termed Regulatory Macrophages (R-MΦ).[11] They hypothesize that the generation of these cells can be exploited to mitigate autoimmunity. Conversely, the deletion of these cells may potentiate 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. Their research has shown that NF-kB p50 homodimers are uniquely involved in IL-10 induction in macrophages, that activation of the MAPK p38 is required for IL-12 production in macrophages, and that macrophage secretory products can exert an intrinsic influence on cytokine production.[13]

Mosser has utilized high throughput RNA sequencing to examine the transcriptomes of the various macrophage subpopulations, and to better understand the dynamics of intracellular infections in macrophages. He provided a simultaneous analysis of macrophages and parasite transcripts over time as L. major established an in vitro infection in human macrophages. Mosser and his lab analyzed L. major gene expression during differentiation. They have profiled host and parasite transcripts in lesions of patients with cutaneous L. braziliensis infections and with diffuse cutaneous infections with L. amazonensis.[14]