Lassiter H A, Watson S W, Seifring M L, Tanner J E
Department of Pediatrics, University of Louisville School of Medicine, Kentucky.
J Infect Dis. 1992 Jul;166(1):53-7. doi: 10.1093/infdis/166.1.53.
The serum concentration of complement factor C9 (C9) was 260 +/- 47 micrograms/ml (+/- SE) in 14 mothers and less than 42 micrograms/ml in each of their 14 neonates. During incubation for 60 min, 11 of 14 maternal sera and 3 of 14 neonatal sera reduced the survival of Escherichia coli O7w:K1:NM to less than 20% of the original inoculum (P less than .03). Eleven neonatal sera did not kill the bacteria. Supplemental C9 (60 micrograms/ml) enhanced the bactericidal capacity of 10 neonatal sera. 125I-labeled C9 was deposited onto E. coli by neonatal sera, but less efficiently than by pooled adult sera. Supplemental IgG enhanced 125I-labeled C9 deposition and potentiated the bactericidal activity of exogenous C9. Therefore, neonatal sera contained diminished concentrations of C9 and killed E. coli inefficiently. In neonatal sera, supplemental C9 was deposited onto E. coli and enhanced bactericidal activity. These effects of C9 were potentiated by supplemental IgG.
14名母亲血清中补体因子C9（C9）的浓度为260±47微克/毫升（±标准误），其14名新生儿血清中C9浓度均低于42微克/毫升。在孵育60分钟期间，14份母亲血清中有11份以及14份新生儿血清中有3份可将大肠杆菌O7w:K1:NM的存活率降至低于初始接种量的20%（P<0.03）。11份新生儿血清不能杀灭细菌。补充C9（60微克/毫升）可增强10份新生儿血清的杀菌能力。125I标记的C9可被新生儿血清沉积到大肠杆菌上，但效率低于混合成人血清。补充IgG可增强125I标记的C9沉积，并增强外源性C9的杀菌活性。因此，新生儿血清中C9浓度降低，杀灭大肠杆菌的效率低下。在新生儿血清中，补充的C9可沉积到大肠杆菌上并增强杀菌活性。C9的这些作用可被补充的IgG增强。
