TLR4 and pneumococcal infection: Some authors showed that the interaction of PLY with TLR4 is involved in induce cytokine production and apoptosis [30, 31], while other research showed that PLY activates the NLRP3/ACS inflammasome to enhance the secretion of pro-inflammatory cytokines IL-1β and IL-18 from macrophages and dendritic cells and contributes to the protection of the host from pneumococcal infection independent of TLR-4 and mediated by K+ influx [24, 32].