T. Chen et al., HEPARIN PROTECTS OPA(-GONORRHOEAE FROM THE BACTERICIDAL ACTION OF NORMAL HUMAN SERUM() NEISSERIA), Infection and immunity, 63(5), 1995, pp. 1790-1795
The pathobiological significance of lipooligosaccharide (LOS) and oute
r membrane opacity protein (Opa) changes in gonorrheal disease are poo
rly understood. We assessed variants of strain MS11mk with different L
OS and Opa phenotypes for their liability to killing by normal human s
era. LOS differences correlated with strikingly disparate susceptibili
ties to serum killing; LOSa variants were serum resistant, LOSb varian
ts were serum sensitive, and sialylation of LOSb variants enhanced the
ir survival (as reported previously). Opa phenotype had little influen
ce on the killing of serum-sensitive LOSb cells that were incubated di
rectly in normal human sera, but preincubation of Opa(+) LOSb variants
in heparin increased their serum resistance whereas Opa(-) LOSb varia
nts showed no change. Some Opa proteins conferred slightly higher resi
stance than others, but heparin preincubation increased serum resistan
ce for variants expressing each of seven Opa proteins. These in vitro
phenomena may relate to conditions within the male urethra where sulfa
te-containing proteoglycans are abundant and where antibody and comple
ment may transude from blood plasma. The results suggest that the sele
ctive advantage for Opa(+) Neisseria gonorrhoeae bacteria observed in
vivo may reflect their ability to utilize host cell components to resi
st kilting by host defenses.