Interactions Between and Altered Bacterial Transcriptional Profiling and Attenuated the Immune Responses of Macrophages.

Interspecies coaggregation promotes transcriptional changes in oral bacteria, affecting bacterial pathogenicity. () and () are common oral inhabitants. The present study investigated the transcriptional profiling of and subsp. in response to the dual-species coaggregation using RNA-seq. Macrophages were infected with both species to explore the influence of bacterial coaggregation on both species' abilities to survive within macrophages and induce inflammatory responses. Results indicated that, after the 30-min dual-species coaggregation, 116 genes were significantly up-regulated, and 151 genes were significantly down-regulated in ; 97 genes were significantly down-regulated, and 114 genes were significantly up-regulated in subsp. . Multiple genes were involved in the biosynthesis and export of cell-wall proteins and carbohydrate metabolism. subsp. genes were mostly associated with translation and protein export. The coaggregation led to decreased expression levels of genes associated with lipopolysaccharide and peptidoglycan biosynthesis. Coaggregation between and subsp. significantly promoted both species' intracellular survival within macrophages and attenuated the production of pro-inflammatory cytokines IL-6 and IL-1β. Physical interactions between these two species promoted a symbiotic lifestyle and repressed macrophage's killing and pro-inflammatory responses.