Sutton JA, et al. - Researchers intended to delineate the human placental macrophage inflammatory response to Group B Streptococcus (GBS) as well as to determine the contribution of protein kinase D (PKD) in mediating such effects. In the presence or absence of a specific, small molecule PKD inhibitor, CRT 0066101, they inoculated GBS into primary human placental macrophages. They found that a strong inflammatory phenotype was elicited by GBS. This phenotype was characterized by the release of inflammatory cytokines (TNFα, IL-1β, IL-6) NLRP3 inflammasome assembly, and NFκB activation. Suppression of these responses was seen with pharmacological inhibition of PKD. Overall, findings highlighted a significant role of PKD in mediating placental macrophage inflammatory activation in response to GBS infection