Senior K E, Demarco de Hormaeche R, Jessop H L
Department of Pathology, University of Cambridge, U.K.
Microb Pathog. 1989 Apr;6(4):251-64. doi: 10.1016/0882-4010(89)90099-5.
The immunogenic potential of lipopolysaccharide (LPS) of a variant of Neisseria gonorrhoeae strain Gc 40 selected by growth in vivo (vivo variant) was investigated in guinea pigs. LPS extracts obtained from the water (WLPS) and the phenol (PLPS) phases of a hot phenol-water extraction were compared for their antigenic capacity and protective effect against infection in subcutaneous chambers. Immunization with PLPS induced significant levels of anti-LPS and anti-epitope C antibodies but WLPS was not antigenic. Two days after challenge, all guinea pigs immunized with WLPS had infections similar to those seen in unimmunized control animals while most animals immunized with PLPS and challenged with either 10(3) or 10(5) gonococci per ml showed low numbers of or no viable gonococci in their chambers. Five days after challenge, however, the same animals had chamber infections with high viable counts similar to controls. Gonococci reisolated from three such animals had physically and antigenically altered lipopolysaccharide and showed patterns of serum sensitivity to pre-challenge chamber fluid from immunized animals which were different from those of the parent vivo variant used for immunization and challenge. The results demonstrate that selection of LPS variants occurs in vivo. This could constitute an immune evasion mechanism.
研究了通过体内生长筛选出的淋病奈瑟菌菌株Gc 40变体的脂多糖（LPS）在豚鼠中的免疫原性潜力。比较了从热酚-水提取物的水相（WLPS）和酚相（PLPS）中获得的LPS提取物的抗原能力以及对皮下腔室感染的保护作用。用PLPS免疫诱导了显著水平的抗LPS和抗表位C抗体，但WLPS没有抗原性。攻击后两天，所有用WLPS免疫的豚鼠都出现了与未免疫对照动物相似的感染，而大多数用PLPS免疫并用每毫升10³或10⁵淋病奈瑟菌攻击的动物，其腔室中的活菌数量很少或没有。然而，攻击后五天，相同的动物出现了与对照相似的高活菌数的腔室感染。从三只这样的动物中重新分离出的淋病奈瑟菌具有物理和抗原性改变的脂多糖，并表现出对免疫动物攻击前腔室液体的血清敏感性模式，这些模式与用于免疫和攻击的亲代体内变体不同。结果表明，LPS变体的选择发生在体内。这可能构成一种免疫逃避机制。
