Targeting Siglec-9/Sialoglycan Interactions to Enhance NK Functions During HIV Infection

靶向 Siglec-9/Sialoglycan 相互作用以增强 HIV 感染期间的 NK 功能

• 批准号: 10326726
• 负责人: Mohamed Abdel Mohsen
• 金额: $ 61.68万
• 依托单位: WISTAR INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-25 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10326726
• 关键词: Antibodies; Antiviral Agents; Autologous; Binding; Binding Proteins; Blocking Antibodies; Blood; Breast Cancer Cell; Breast Cancer Model; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; Carbohydrates; Cell model; Cell surface; Cells; Chromium; Cleaved cell; DNA; Data; Enzymes; Exhibits; FCGR3B gene; Goals; HIV; HIV Infections; Hand; Human; Immune; Immunologic Surveillance; Immunology; In Vitro; Individual; Interleukin-15; Leukocytes; Ligands; Longevity; Malignant Neoplasms; Mediating; Mutate; Natural Killer Cells; Nature; Neuraminidase; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Phenotype; Polysaccharides; Population; RNA; Role; Sialic Acids; Spleen; Surface; T-Lymphocyte; Testing; Time; Trastuzumab; Viral; antiretroviral therapy; cancer cell; carbohydrate binding protein; cytotoxic; cytotoxicity; glycosylation; humanized mouse; immune checkpoint; in vivo; interdisciplinary approach; mouse model; neutralizing antibody; novel; novel strategies; perforin; prevent; programmed cell death protein 1; receptor; sialic acid binding Ig-like lectin; tumor; viral rebound

PROJECT SUMMARY: The functions of Natural Killer (NK) cells can be influenced by the cell-surface glycosylation of their target cells. A subset of CD56dim NK cells expresses the Sialic acid-binding protein Siglec- 9. This subset has a high cytolytic activity; however, Siglec-9 itself is an inhibitory receptor that restrains the cytolytic ability of this otherwise highly cytotoxic population. Harnessing the cytotoxic capacity of this population has not been evaluated as an approach for eradicating HIV. In our preliminary studies and focusing first on NK cells, we found that levels of Siglec-9+ CD56dim NK cells inversely correlate with CD4+ T cell-associated HIV DNA during antiretroviral therapy (ART)-suppressed HIV infection. Furthermore, Siglec-9+ CD56dim NK cells exhibited higher cytotoxicity towards HIV+ cells compared to Siglec-9- NK cells. These data are consistent with the highly cytotoxic nature of the Siglec-9+ NK cells. However, consistent with the known inhibitory function of the Siglec-9 molecule itself, blocking Siglec-9 enhanced NK cells' ability to kill HIV+ cells in vitro. Focusing next on target cells, we found that HIV latently-infected CD4+ T cells exhibit high levels of the Siglec-9 ligand, α2-3 Sialic acid, compared to HIV productively-infected or uninfected cells. We also developed a novel approach to block Siglec/Sialic acid interactions during HIV infection by conjugating Sialidase (enzyme cleaves Sialic acid) to four HIV broadly neutralizing antibodies (bNAbs). These conjugates (in hand) can be used in conjunction with drugs that reactivate HIV latently-infected cells to achieve a functional HIV cure. We pilot tested one of these conjugates and found it able to selectively desialylate the surface of HIV+ cells and enhance NK capacity to kill these infected cells in vitro. Together, our data support our central hypothesis that Siglec/sialoglycan interactions contribute to the ability of HIV-infected cells to evade NK immune surveillance and that blocking these interactions, via selective desialylation of HIV-infected cells, will enhance the capacity of NK cells to clear HIV-infected cells. In Aim 1: we will test the hypothesis that Siglec-9/Sialic acid interactions contribute to the ability of HIV latently-infected cells to evade NK immune surveillance. In (1a), we will determine the role of Siglec-9 in the ability of NK cells to kill HIV+ cells, and in (1b), we will determine the role of α2-3 Sialic acid in the ability of HIV latently-infected CD4+ T cells to evade killing by NK cells. In Aim 2: we will test the hypothesis that HIV bNAb- Sialidase conjugates reduce the size of the HIV reservoir (2a) in vitro and (2b) ex vivo, and (2c) delay viral rebound in vivo using a modified version of the splenic-injected primary HIV-infected reservoir (SPHIR-IL15) non-fetal humanized mouse model with high NK longevity. We also will confirm the mechanism by which bNAb- Sialidase conjugates enhance NK cell antiviral function by examining the role of Fc-mediated functions and Siglec-binding in NK targeting. Our interdisciplinary approach is taking advantage of recent advances in the emerging field of glyco-immunology to enhance NK cell capacity to kill HIV+ cells in ART-suppressed individuals. Our goal is to provide a novel mechanism and approach that can be harnessed to functionally cure HIV infection.

项目摘要：天然杀手（NK）细胞的功能可能受细胞表面的影响 其靶细胞的糖基化。 CD56DIM NK细胞的子集表达唾液酸结合蛋白siglec- 9。该子集具有较高的细胞溶解活性。但是，SIGLEC-9本身是一种抑制受体，可限制 这种原本高度细胞毒性种群的细胞溶解能力。利用该人群的细胞毒性能力 尚未被评估为消除艾滋病毒的方法。在我们的初步研究中，首先关注NK 细胞，我们发现SIGLEC-9+ CD56DIM NK细胞的水平与CD4+ T细胞相关的HIV DNA成反比 在抗逆转录病毒疗法（ART）抑制的HIV感染期间。此外，SIGLEC-9+ CD56DIM NK细胞暴露 与SIGLEC-9-NK细胞相比，对HIV+细胞的细胞毒性更高。这些数据与高度一致 SIGLEC-9+ NK细胞的细胞毒性性质。但是，与SIGLEC-9的已知抑制功能一致 分子本身，阻断SIGLEC-9增强了NK细胞在体外杀死HIV+细胞的能力。关注目标 细胞，我们发现HIV受感染的CD4+ T细胞暴露于Siglec-9配体的高水平，α2-3唾液酸， 与HIV有效感染或未感染的细胞相比。我们还开发了一种新颖的方法来阻止 在HIV感染期间，Siglec/唾液酸相互作用通过将唾液酸酶（酶裂解唾液酸裂解至四个） HIV广泛中和抗体（BNAB）。这些结合物（手头）可与药物一起使用 这重新激活了艾滋病毒的潜在感染细胞，以实现功能性HIV治疗。我们试行测试了这些偶联者之一 并发现可以选择性地将HIV+细胞表面脱酰基并增强NK杀死这些感染的能力 细胞体外。我们的数据共同支持我们的中心假设，即Siglec/Sialoglycan相互作用有助于 具有艾滋病毒感染细胞逃避NK免疫监视的能力并通过 对感染HIV的细胞的选择性脱酰化，将增强NK细胞清除感染HIV感染细胞的能力。 在AIM 1中：我们将检验以下假设：Siglec-9/唾液酸相互作用有助于HIV的能力 潜在感染的细胞以逃避NK免疫监测。在（1a）中，我们将确定Siglec-9在 NK细胞杀死HIV+细胞的能力，在（1B）中，我们将确定α2-3唾液酸在HIV能力中的作用 潜在感染的CD4+ T细胞逃避NK细胞杀死。在AIM 2中：我们将检验以下假设：HIV BNAB- 唾液酸酶结合物在体外和（2B）的体外减少HIV储存库（2a）的大小，并且（2C）延迟病毒 使用经过修改的脾注射艾滋病毒感染的储层（SPHIR-il15）的修改版本反弹 具有高NK寿命的非拟合人源化小鼠模型。我们还将确认bnab-的机制 唾液酸酶结合物通过检查FC介导的功能和 NK靶向中的SIGLEC结合。我们的跨学科方法是利用 Glyco-免疫学的新兴领域可增强NK细胞杀死Art抑制个体的HIV+细胞的能力。 我们的目标是提供一种新型的机制和方法，可以利用功能来治愈HIV感染。