Development of antibodies to capsule of carbapenem resistant Klebsiella pneumonia

描述(由申请人提供)：碳青霉烯耐药肺炎克雷伯氏菌(CR-KP)分离株在全球范围内出现，包括在美国。美国疾病控制与预防中心报告称，患病率从2001年的1.6%上升到2011年的10.4%。CR-KP主要引起肺炎、败血症和尿路感染。大多数患者在与卫生保健相关的环境中感染这种病原体，但也观察到来自社区的健康人感染CR-KP。一个问题是，许多CR-KP分离株保持完全毒力，甚至对氨基糖苷类药物也经常产生抗药性。二线储备抗生素，如季环素或多粘菌素，要么疗效低，要么毒性很大，特别是对肾功能受损的患者。因此，侵袭性CrKP感染的死亡率很高，从50%到80%不等。目前还看不到针对革兰氏阴性菌的新的有效药物类别，因此必须探索替代治疗方案。这项应用提出了产生针对CR-KP的胶囊多糖(CPS)的单抗。对40株CR-KP分离株的分子被膜分型表明，尽管有共同的ST258克隆背景，但这些分离株中的CP是异质性的，因此必须产生交叉反应的mAb才能成功地覆盖临床分离株的变异性。在目标1中，我们提出了几种策略来产生交叉反应的单抗，并增加产生免疫球蛋白的杂交瘤的数量，因为这种亚型是首选的亚型。在目标2中，我们建议根据mAbs与不同包膜类型的CrKP结合并有效增强宿主的能力来表征mAbs的特性 对不同的CrKP菌株的反应。目标是生成一份最佳候选人的排名列表，然后将其人性化并进一步发展。

DESCRIPTION (provided by applicant): Carbapenem resistant Klebsiella pneumonia (CR-Kp) isolates are emerging worldwide including in the US. The CDC has reported an increase in prevalence from 1.6% in 2001 to 10.4% in 2011. CR-Kp causes predominantly pneumonia, sepsis and urinary tract infections. Most patients acquire this pathogen in health care associated settings but infections with CR-Kp have also been observed in healthy people from the community. One problem is that many of the CR-Kp isolates retain full virulence and often become resistant even to aminoglycosides. The 2nd line reserve antibiotics such as Tycycline or Polymyxin either have low efficacy or are very toxic especially in patients with compromised renal function. As a result, the mortality of invasive Cr-Kp infections is high and ranges from 50-80%. New effective drug classes against gram-negative bacteria are not in sight hence alternative treatment regimens have to be explored. This application proposes to generate mAbs to the capsular polysaccharide (CPS) of CR-Kp. Molecular capsule typing of 40 CR-KP isolates demonstrates that despite a common ST258 clonal background the CPS in these isolates is heterogeneous and therefore cross-reactive mAbs will have to be generated in order to successfully cover the variability of clinical isolates. In aim 1 we propose several strategies o generate cross-reactive mAbs and to also increase the number of hybridomas that produce IgG as this isotype is the preferred isotype. In aim 2 we propose to characterize the mAbs with respect to their ability to bind to diverse capsule-types of Cr-Kp and effectively enhance the host response to diverse Cr-Kp isolates. The goal is to generate a rank list of best candidates that are then humanized and further developed.