Immunotherapy of KPC Infection

对人类健康持续和新出现的威胁是耐多药细菌感染。其中包括 威胁，产碳青霉烯酶克雷伯菌已被世界卫生组织认可 世界卫生组织和疾病控制中心对人类健康构成全球威胁，特别是在 医院环境。在临床上，这些感染通常表现为影响患者的机会性感染 共病，如免疫抑制药物、运动状态不佳、机械通气和 肾脏疾病。此外，恶性血液病和实体器官和干细胞移植接受者 处于危险之中。最近，有报道说有粘液包膜的超强毒株，但在一些地区的带菌率 亚洲人的粪便感染率接近5%，远远超过临床感染率，这表明宿主因素是 很重要。非粘液型ST258C4菌株对WT小鼠和小鼠的肺部接种均无毒力 缺乏T细胞和B细胞的RAG-/-小鼠。相比之下，Rag2、IL2RG-/-另外缺乏NK细胞和先天 淋巴样细胞，易受感染，并有死亡，这是相关的细菌传播。 肺组织单细胞RNAseq检测结果显示，NK细胞和第3组先天淋巴样细胞 与细菌清除有关。在初步研究中，只有NK细胞和第3组的双重拮抗作用 ILCs导致ST258感染，提示这两个细胞群是宿主防御ST258的关键 有机体。由于IL-22：Fc是肠道移植物抗宿主病和糖尿病足溃疡的临床试验，我们调查了 如果全身应用IL-22：Fc可作为免疫治疗。初步研究表明IL-22：Fc 可显著降低易感Rag2-/-、IL2RG-/-小鼠的细菌负荷。来检查这些是否 细胞反应受到临床相关免疫抑制的干扰，我们使用FK506，这是 用于固体器官移植，给小鼠。FK506治疗增加了感染的易感性，并降低了 肺组织中的IFNG、IL17A和IL22。因此，我们开发了遗传和药理学模型，使我们能够 提出以下可检验假设：ST258C4感染需要NK细胞和第3组ILC细胞 清除，这些群体被钙调神经磷酸酶抑制。此外，我们假设细胞因子 可以开发基于免疫治疗的方法来增强内源性宿主反应，以清除这种感染。我们 我将使用非粘液性(C4)和高粘液性来测试以下特定目标的假设 KPC菌株：特定目的1.检验NK细胞和第3组固有淋巴样细胞均为 对KPC感染的肺粘膜免疫所需的。具体目标2.开发一种临床和 KPC感染的药理学相关模型。具体目标3.检验系统性或局部性的预测 免疫治疗是控制KPC感染的有效方法。

A continued and emerging threat to human health are multi-drug resistant bacterial infections. Among these threats, carbapenemase producing strains of Klebsiella spp has been recognized by the World Health Organization and the Centers for Disease Control has a global threat to human health particularly in the hospital setting. Clinically these infections often appear to be opportunistic infections affecting patients with co-morbidities such as immunosuppressive drugs, poor performance status, mechanical ventilation, and kidney disease. In addition, hematologic malignancies and solid organ and stem cell transplant recipients are at risk. Recently hyervirulent strains with mucoid capsule have been reported but carriage rates in areas of Asia can approach 5% in stool, which far exceeds the rate of clinical infection, suggesting host factors are important. Pulmonary inoculation of the non-mucoid ST258C4 strain was avirulent in WT mice as well as Rag-/- mice which lack T and B cells. In contrast Rag2, Il2rg -/- which additionally lack NK cells and innate lymphoid cells, were susceptible to infection and had mortality, which was associated bacterial dissemination. Single cell RNAseq of lung tissue demonstrated that NK cells and group 3 innate lymphoid cells were associated with bacterial clearance. In preliminary studies, only dual antagonism of both NK cells and group 3 ILCs resulted in ST258 infection suggesting these two cell populations are key to host defense against this organism. As IL-22:Fc is clinical trial for gut graft versus host disease and diabetic foot ulcers, we investigated if systemic IL-22:Fc administration could be used as immunotherapy. Preliminary studies show that IL-22:Fc can substantially reduce bacterial burdens in mice susceptible Rag2-/-, Il2rg -/- mice. To examine if these cellular responses were perturbed by clinically relevant immunosuppression, we administered FK506, which is used in solid organ transplant, to mice. FK506 treatment increased susceptibility to infection and reduced IFNg, Il17a, and Il22 in the lung. Thus, we have developed genetic and pharmacological models that allow us to propose the following testable hypothesis: ST258 C4 infection requires NK cells and group 3 ILC cells for clearance and these populations are inhibited by calcineurin inhibition. Moreover we hypothesize that cytokine based immunotherapy can be developed to augment endogenous host responses to clear this infection. We will test these hypotheses with the following specific Aims using both non-mucoid (C4) as well as hypermucoid strains of KPC: Specific Aim 1. Test the prediction that both NK cells and group 3 innate lymphoid cells are required for lung mucosal immunity against Kpc infection. Specific Aim 2. Develop a clinically and pharmacologically relevant model of Kpc infection. Specific Aim 3. Test the prediction that systemic or local immunotherapy is effective in controlling Kpc infection.