Immunotherapy of KPC Infection

对人类健康的持续和新出现的威胁是多重耐药细菌感染。其中 克雷伯氏菌属的碳青霉烯酶生产菌株已被世界卫生组织认可， 该组织和疾病控制中心对人类健康构成全球威胁，特别是在 医院设置。临床上，这些感染通常表现为机会性感染， 合并症，如免疫抑制药物、体能状态差、机械通气，以及 肾病此外，血液恶性肿瘤和实体器官和干细胞移植受者是 处于危险之中最近报道了具有粘液样荚膜的超毒株，但 亚洲在粪便中的感染率可接近5%，远远超过临床感染率，这表明宿主因素 重要.非粘液样ST 258 C4菌株的肺部接种在WT小鼠中以及在小鼠中是无毒力的。 缺乏T和B细胞的Rag-/-小鼠。相比之下，另外缺乏NK细胞和先天性NK细胞的Rag 2、Il 2 rg-/- 淋巴样细胞，易感染，并有死亡，这是相关的细菌传播。 肺组织的单细胞RNAseq证明NK细胞和第3组先天淋巴样细胞在肺组织中表达。 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， ILC导致ST 258感染，表明这两个细胞群是宿主防御这种感染的关键。 有机体由于IL-22：Fc是肠移植物抗宿主病和糖尿病足溃疡的临床试验，我们研究了 如果全身性IL-22：Fc给药可用作免疫疗法。初步研究表明，IL-22：Fc 可显著降低小鼠易感Rag 2-/-、Il 2 rg-/-小鼠中的细菌负荷。为了检查这些 细胞反应受到临床相关免疫抑制的干扰，我们给予FK 506， 用于小鼠的实体器官移植。FK 506治疗增加了对感染的易感性， IFNg、IL 17 a和IL 22。因此，我们开发了遗传和药理学模型， 提出以下可检验的假设：ST 258 C4感染需要NK细胞和第3组ILC细胞， 清除，并且这些群体被钙调磷酸酶抑制所抑制。此外，我们假设细胞因子 可以开发基于免疫疗法的免疫疗法以增强内源性宿主应答以清除这种感染。我们 我将使用非粘液（C4）和高粘液（C4）， KPC菌株：特异性目标1。测试NK细胞和第3组先天淋巴细胞都是 这是肺粘膜免疫抵抗Kpc感染所必需的。具体目标2。发展一个临床和 Kpc感染相关模型。具体目标3。测试预测，系统或局部 免疫疗法在控制Kpc感染方面是有效的。

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.