Impact of the deletion of PG1348 (dhSphK1) on cytokine and chemokine response. Human macrophage-like THP-1 cells were directly cultured with P. gingivalis W83 (WT) and the ΔPG1348 (dhSphk1) mutant cells. Supernatant fluids were collected at 2, 6, and 24 h, and the levels of TNF-a, IL-1b, IL-6, IL-10, RANTES, and IL-8 were measured by multiplex immunoassay. Medium alone (M) served as an unchallenged (negative) control. THP-1 cells cultured with the ΔdhsphK1 mutant and with the WT produced similar level of cytokines and chemokines; however, there was a trend toward a slightly higher cytokine response to the ΔdhsphK1 mutant. Multiplicity of infection (MOI), 100; data are presented as mean ± SEM (n = 3 independent experiments); P < 0.05.