Development of a novel therapeutic to treat snakebite induced necrosis in sub-Saharan Africa

拟议的博士学位是开发针对撒哈拉以南非洲蛇毒引起的坏死的靶向治疗方法。目前，也是唯一的蛇咬伤治疗方法（抗蛇毒血清——从高度免疫的马/羊身上提取的抗蛇毒血清），虽然能有效逆转毒蛇咬伤的潜在致命全身效应，但在消除/逆转组织坏死效应方面是无效的。据全球估计，每年有40万人因毒液引起的坏死而毁容或致残。仅在撒哈拉以南非洲地区，估计每年就有1.4万例直接因蛇咬伤而截肢。然而，人们对单个毒液成分是如何导致坏死的知之甚少。虽然有已发表的文献表明哪些蛋白质被认为是导致坏死的必要因素，但很少有人单独关注这种病理，特别是在撒哈拉以南非洲物种中。开发一种治疗毒液引起的坏死的疗法是迫切的临床需要，更好地了解潜在的过程将是非常宝贵的。根据地理分布、人类咬伤的频率和造成坏死的严重程度，已经确定了三个关键的撒哈拉以南物种，即斑鼻蠓（Echis ocel/atus）、斑鼻蠓（Bitis arietans）和nigricollis。这三个物种的毒液，以及个别毒素，将构成整个博士课程的基础。博士学位的范围包括在这三种毒液中识别坏死诱导毒素（NIT），检查它们在体外和体内模型中的作用，并设计（和测试）NIT靶向治疗方法。这也有可能进一步扩大博士学位，包括高度诱导坏死的亚洲物种，如Daboia russelii和Ca//ose/asma rhodostoma，使用相同的方法。博士学位的第一年将致力于从撒哈拉以南非洲的三种目标毒液中识别和分离这些nit。为了实现这些目标，将采用几种不同的方法；生物信息学，重组蛋白表达，层析和生物活性测定。每一种不同的技术都构成了它自己独特的工作阶段。

The proposed PhD is to develop a targeted therapeutic against snake venom-induced necrosis in sub-Saharan Africa. The current, and only, treatment for snakebite (antivenom - lgG from horses/sheep hyperimmunised with venom/s)), while effective at reversing the potentially lethal systemic effects of envenoming is ineffective at negating/reversing the tissue-necrotic effects. The global estimates are that 400'000 individuals are left disfigured or disabled every year due to venom-induced necrosis. In sub-Saharan Africa alone there are an estimated 14'000 amputations each year directly attributable to snakebite. However, little is understood about how individual venom components act to cause necrosis. Whilst there is published literature indicating which proteins are thought to be integral to the causation of necrosis, little has been done focusing on this pathology alone, especially in sub-Saharan African species. The development of a therapy to treat venom-induced necrosis is an urgent and compelling clinical need, and a better understanding of the underlying processes will be invaluable. Three key sub- Saharan species (based on geographical distribution, frequency of human bites and severity of necrosis caused) have been identified as Echis ocel/atus, Bitis arietans and Naja nigricollis. The venoms, and individual toxins, from these three species will form the basis of the entire PhD.The scope of the PhD covers the identification of necrosis-inducing toxins (NITs) within all three of these venoms, examining their effects in ex vivo and in vivo models, and designing (and testing) NIT targeting therapeutics. These is also the potential in expand the PhD further to include highly necrosis-inducing Asian species, such as Daboia russelii and Ca//ose/asma rhodostoma, using the same approaches. The first year of the PhD will be dedicated to the identification and isolation of these NITs from the three sub-Saharan Africa target venoms. In order to achieve these aims several different methodologies will be applied; bioinformatics, recombinant protein expression, chromatography and bioactivity assays. Each of these different techniques constitutes its own distinct phase of work.