Skip to main content
. 2022 Oct 20;13:1028796. doi: 10.3389/fmicb.2022.1028796

Figure 3.

Figure 3

Correlation between the presence of NeuAc in bacterial LPSs and complement activation. There are four possible ways of C activation depending on sialylated LPSs and outer membrane proteins. (A) The sialylated LOS of Haemophilus influenzae and Neisseria gonorrhoeae inhibits the activation of the alternative pathway (AP) of the complement system by binding of factor H. The binding of factor H requires the presence of gonococcal outer membrane protein PorB (Ram et al., 1998; Figueira et al., 2007; Madico et al., 2007). (B) Enterobacteriaceae such as Escherichia coli O104, E. coli O24, E. coli O56, Citrobacter braakii O37 and Salmonella O48 were killed via the AP pathway activation although they possessed sialylated LPSs (Bugla-Płoskońska and Doroszkiewicz, 2006; Bugla-Płoskońska et al., 2010a,b). (C) LPS with a low content (near the limit of detection) of sialic acid in LPS of Salmonella Isaszeg enabled C3 activation on OMPs in the range of molecular masses of 35–48 kDa (Futoma-Kołoch et al., 2015). (D) LPS with a high content of sialic acid of S. Ngozi and S. subsp. arizonae impeded C3 activation by OMPs in the range of molecular masses of 35–48 kDa (Futoma-Kołoch et al., 2015).