Protective anti-LPS antibodies: what are they?

描述（由申请人提供）：基于霍乱弧菌脂多糖（脂多糖）的霍乱疫苗的开发是由杀弧菌抗脂多糖反应与免疫的相关性证明的。稻叶和小川两种O1（血清组）LPS血清型与地方性和大流行性霍乱有关。两种LPS血清型均可在感染或接种后诱导保护性抗体。在结构上，血清型是相同的，除了末端糖（perosamine）在小川的2位有甲氧基，而在稻叶的2位有羟基。小川LPS的末端糖是一个保护性的B细胞表位。合成小川型霍乱弧菌过氧化物胺六糖偶联BSA （CHO-BSA）诱导的保护性抗体。我们推测稻叶脂多糖的末端糖也会诱导保护性抗体。稻叶新糖缀合物确实诱导了抗体，但令人惊讶的是，它们没有保护作用。与此相反，用纯化的天然稻叶脂多糖免疫可诱导高保护性抗体。初步数据表明稻叶CHO-BSA偶联物诱导的稻叶抗体在ELISA中有足够的亲和力，但在体内没有足够的保护作用。用天然LPS引物，然后提供稻叶CHO-BSA，在10天内产生高ELISA滴度和具有保护性的抗体。我们推测稻叶脂多糖和稻叶CHO-BSA选择了不同的B细胞，稻叶CHO-BSA可以与稻叶脂多糖选择的B细胞发生交叉反应，使其扩增，从而可能为那些生活在具有记忆性B细胞但体液免疫减弱的流行地区的人提供有效的疫苗免疫原。对两种稻叶免疫原产生单克隆抗体（mAb），以确定免疫过程中是否选择了不同的B细胞。R21补助金非常适合这些需要试剂开发来解决霍乱生物学基本问题的研究。一种新的技术，表面等离子体共振（SPR）将被用来表征单克隆抗体的亲和力。实验是有风险的，因为它们需要生成多种试剂来完成抗lps抗体的群体分析。这项研究是高回报的，因为无论确切的特异性如何，将产生试剂来绘制稻叶脂多糖末端糖的抗体库。我们将澄清anti-V的“类型”。具有保护作用的霍乱LPS抗体，因此证实或不证实稻叶新偶联物作为疫苗成分的使用。

DESCRIPTION (provided by applicant): Development of a V. cholerae LPS (lipopolysaccharide)- based cholera vaccine is justified by the correlation of vibriocidal anti-LPS responses with immunity. Two O1 (serogroup) LPS serotypes, Inaba and Ogawa are associated with endemic and pandemic cholera. Both LPS serotypes induce protective antibody following infection or vaccination. Structurally, the serotypes are identical except for the terminal sugar (perosamine) which has a methoxyl group at position 2 in Ogawa, but a hydroxyl group in Inaba. The terminal sugar of the Ogawa LPS is a protective B cell epitope. Synthetic perosamine hexasaccharides of V. cholerae, serotype Ogawa coupled to BSA (CHO-BSA) induced protective antibody. We hypothesized that the terminal sugar of Inaba LPS would also induce protective antibody. Inaba neoglycoconjugates did induce antibodies but surprisingly they were not protective. In contrast, immunization with purified native Inaba LPS induced highly protective antibody. Preliminary data indicate that Inaba antibodies induced by the Inaba CHO-BSA conjugates have sufficient affinity to score in an ELISA but not enough to be protective in vivo. Priming with native LPS and then providing the Inaba CHO-BSA resulted in high ELISA titers in 10 days and antibodies that are protective. We hypothesize that Inaba LPS and Inaba CHO-BSA select different B cells, and that Inaba CHO-BSA can cross react with Inaba LPS-selected B cells to expand them and thus may provide an effective vaccine immunogen for those living in endemic areas with memory B cells but waning humoral immunity. Monoclonal antibodies (mAb) will be generated to the two Inaba immunogens to determine if different B cells are selected during immunization. An R21 grant is well suited for these studies that require reagent development to address a fundamental question in cholera biology. A new technology, surface plasmon resonance (SPR) will be used to characterize the affinity of the mAbs. The experiments are risky as they require generation of multiple reagents to complete the population analysis of anti-LPS antibodies. The study is high pay off because reagents, regardless of the exact specificity, will be generated that will map the antibody repertoire for Inaba LPS's terminal sugar. We will clarify the "type" of anti-V. cholerae LPS antibodies that are protective and thus substantiate or not the use of Inaba neoconjugates as a vaccine component.