HL-Development and Pharmacology of novel lipidic rAHF and biotherapeutics

 说明书(由申请人提供)几种挽救生命的蛋白质疗法的安全性和有效性因不需要的免疫反应而受到影响。目前还没有可行的临床选择来减少或逆转这些反应。我们的目标是开发蛋白质输送策略，通过减少或逆转不需要的免疫反应来提高蛋白质药物的治疗效果。在之前的项目期间，我们观察到，在磷脂酰丝氨酸(PS)存在的情况下，小鼠暴露于蛋白质疗法中，导致了对蛋白质的抗原特异性免疫耐受/低反应性，从而导致了我们的中心假设，即PS具有免疫调节作用，并具有将免疫原性蛋白质转化为耐受性的能力。为了充分实现这一观察的临床潜力，有必要确定PS的结构特征，这些结构特征有助于将免疫原转化为耐受原(SA1)，并利用这些信息来减少(SA2)和逆转(SA3)对治疗蛋白的不必要的免疫反应，并提高其治疗效果。在SA1中，我们假设PS将树突状细胞从免疫性表型转化为耐受性表型，产生调节性T细胞，进而抑制抗原特异性T细胞和B细胞。我们研究了PS的结构和生物物理决定因素，这些决定因素编程树突状细胞发送耐受信号而不是免疫原信号。由于小鼠在PS存在的情况下预先暴露于FVIII显著降低了它们在与FVIII再次攻击时的免疫反应，在SA2中，我们研究了另外两种免疫原性治疗蛋白的类似预治疗方法，以防止或减少治疗期间对这些蛋白的不必要的免疫反应。具体地说，我们将用酸性α葡萄糖苷酶(Pompe病中的GAA，一种溶酶体储存障碍)和因子IX(在血友病B中，一种出血性疾病)来测试这种方法。我们将确定参与耐受诱导的免疫细胞，并确定耐受诱导对这两种替代疗法疗效的影响。在SA3中，我们开发了临床策略来逆转对FVIII、FIX和GAA的既定反应，从而提高这些出血和溶酶体疾病的治疗效果。由于PS暴露在分泌性小泡(如凋亡小体)的外层和细胞释放的外切体上，我们提出并将检验这样一个假设，即模仿这些天然小泡的脂肪颗粒将逆转对治疗性蛋白的已建立的免疫反应。我们在SA3中的目标是优化免疫方案，并测试一种模拟分泌小泡的人造脂质颗粒，以逆转不想要的已建立的免疫反应。这些研究有望带来新的临床策略，以减少和逆转对治疗性蛋白质的免疫反应，从而提高几种基于蛋白质的救命疗法的疗效。

 DESCRIPTION (provided by applicant) The safety and efficacy of several life-saving protein therapeutics are compromised by unwanted immune responses. Currently there are no viable clinical options to reduce or reverse these responses. Our goal is to develop protein delivery strategies that improve therapeutic efficacy of protein drugs by reducing or reversing unwanted immune responses. During the previous project period, we observed that exposure of mice to protein therapeutics in the presence of phosphatidylserine (PS) resulted in an antigen specific immunological tolerance/hypo-responsiveness towards the protein, leading to our central hypothesis that PS is immune regulatory and has the capacity to convert immunogenic proteins into tolerogens. To fully realize the clinical potential of this observation, it is necessary to determine the structural characteristics of PS that contribute to its ability to convert an immunogen into a tolerogen (SA1), and to use this information to reduce (SA2) and reverse (SA3) unwanted immune responses to therapeutic proteins and improve their therapeutic efficacy. In SA1 we hypothesize that PS converts dendritic cells from an immunogenic to a tolerogenic phenotype, generating regulatory T-cells that in turn suppress antigen-specific T-cells and B-cells. We investigate the structural and biophysical determinants of PS that program dendritic cells to send tolerogenic over immunogenic signals. Since pre-exposure of mice to FVIII in the presence of PS significantly reduced their immune response during re-challenge with FVIII, in SA2, we investigate a similar pre-treatment approach with two other immunogenic therapeutic proteins to prevent or reduce unwanted immune responses to these proteins during therapy. Specifically we will test this approach with acid alpha glucosidase (GAA in Pompe disease, a lysosomal storage disorder) and Factor IX (in Hemophilia B, a bleeding disorder). We will determine the immune cells that are involved in the induction of tolerance, and establish the impact of such tolerance induction on the efficacy of these two replacement therapies. In SA3, we develop clinical strategies to reverse established responses to FVIII, FIX and GAA, and thereby improve the efficacy of treatments for these bleeding and lysosomal disorders. Since PS is exposed in outer layer of secreted vesicles such as apoptotic bodies and on exosomes released from cells, we propose and will test the hypothesis that lipid particles mimicking these natural vesicles will reverse the established immune responses to therapeutic proteins. Our goal in SA3 is the optimization of immunization protocol and testing of an artificial lipid particle tha mimics the secreted vesicles, to reverse the unwanted established immune responses. These studies are expected to lead to novel clinical strategies to reduce and reverse immune responses to therapeutic proteins and thereby improve the efficacy of several lifesaving protein-based therapies.