TIMD4

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)-- Cero Therapeutics Holdings, Inc., (NASDAQ:CERO) ("CERo") an innovative immunotherapy company seeking to advance the next generation of engineered T cell therapeutics that employ phagocytic mechanisms today announced the publication in Clinical Cancer Research, a journal of the American Association for Cancer Research, a paper titled “Therapeutic Targeting of TIM-4-L With Engineered T Cells for Acute Myeloid Leukemia.” The paper details preclinical studies by CERo analyzing its lead clinical candidate CER-1236 in targeting Acute Myelogenous Leukemia (AML) tumor cells from human patients, and the candidate’s killing effects on these tumor cells. The results in the paper found that the target for CER-1236 is found in the large majority (83%) of leukemic cells extracted from the bone marrow from patients, and that more importantly CER-1236 effectively eliminated leukemic cells in the company’s experiments. Finally, the target for CER-1236 was found by CERo to be highly expressed and detectable across common AML genetic classification subtypes, including patient samples with adverse risk mutations in TP53, ASXL1 and RUNX1. “This new publication provides support for our plans to test CER-1236 in AML patients in our planned Phase I clinical trial, and moreover extends the scientific data we have produced showing the target for CER-1236 is present on tumor cells from diverse cancers, including ovarian, non-small cell lung cancer (NSCLC), and B cell malignancies,” said Daniel Corey M.D, Ph.D, CERo’s Founder and Chief Technology Officer. “We’re very pleased with this publication in Clinical Cancer Research supporting our near term plans to advance CER-1236 into the clinic. As we have previously reported, CERo plans to Investigational New Drug (IND) application in the first half of 2024, and is targeting initial treatment of AML patients as well as B Cell lymphoma patients before the end of the year,” said Brian G Atwood, CERo’s Chairman and Chief Executive Officer. About CERo Therapeutics, Inc. CERo is an innovative immunotherapy company advancing the development of next generation engineered T cell therapeutics for the treatment of cancer. Its proprietary approach to T cell engineering, which enables it to integrate certain desirable characteristics of both innate and adaptive immunity into a single therapeutic construct, is designed to engage the body’s full immune repertoire to achieve optimized cancer therapy. This novel cellular immunotherapy platform is expected to redirect patient-derived T cells to eliminate tumors by building in engulfment pathways that employ phagocytic mechanisms to destroy cancer cells, creating what CERo refers to as Chimeric Engulfment Receptor T cells ("CER-T"). CERo believes the differentiated activity of CER-T cells will afford them greater therapeutic application than currently approved chimeric antigen receptor ("CAR-T") cell therapy, as the use of CER-T may potentially span both hematological malignancies and solid tumors. CERo anticipates initiating clinical trials for its lead product candidate, CER-1236, in 2024 for hematological malignancies. Forward-Looking Statements This communication contains statements that are forward-looking and as such are not historical facts. This includes, without limitation, statements regarding the financial position, business strategy and the plans and objectives of management for future operations of CERo. These statements constitute projections, forecasts and forward-looking statements, and are not guarantees of performance. Such statements can be identified by the fact that they do not relate strictly to historical or current facts. When used in this communication, words such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “strive,” “would” and similar expressions may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. When CERo discusses its strategies or plans, it is making projections, forecasts or forward-looking statements. Such statements are based on the beliefs of, as well as assumptions made by and information currently available to, CERo’s management. Actual results could differ from those implied by the forward-looking statements in this communication. Certain risks that could cause actual results to differ are set forth in CERo’s filings with the Securities and Exchange Commission, including its Current Report on Form 8-K, as amended, filed on February 27, 2024, and the documents incorporated by reference therein. The risks described in CERo’s filings with the Securities and Exchange Commission are not exhaustive. New risk factors emerge from time to time and it is not possible to predict all such risk factors, nor can CERo assess the impact of all such risk factors on its business, or the extent to which any factor or combination of factors may cause actual results to differ materially from those contained in any forward-looking statements. Forward-looking statements are not guarantees of performance. You should not put undue reliance on these statements, which speak only as of the date hereof. All forward-looking statements made by CERo or persons acting on its behalf are expressly qualified in their entirety by the foregoing cautionary statements. CERo undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

组织驻留巨噬细胞(TRM)在免疫和组织修复中具有独特的转录特征和功能，同时也是小鼠和人体肿瘤相关巨噬细胞(TAM)的重要来源。然而人和小鼠中的巨噬细胞分子生物学描述并不相同。TRM异质性对TAM的影响在肺癌、胰腺癌和乳腺癌的小鼠模型中，组织驻留巨噬细胞来源的肿瘤相关巨噬细胞(TRM-TAMs)积极支持早期肿瘤扩散并促进肿瘤生长。TRM-TAM在不同的癌症中表现出不同的功能特性。例如，胰腺中的TRM-TAM表现出独特的促纤维化表型，产生和重塑细胞外基质分子；肺TRM-TAM则通过诱导肿瘤细胞上皮-间充质转化和突出的Treg细胞诱导来减弱抗肿瘤适应性免疫反应，从而促进肿瘤侵袭；TIM4+胸/腹膜腔驻留巨噬细胞通过将CD8+ T细胞隔离在远离肿瘤靶点的部位上来损害抗肿瘤免疫。一组可自我更新的CD163+ TIM4+ 组织驻留网膜巨噬细胞通过为肿瘤干细胞提供保护性生态位，与卵巢癌细胞的转移扩散有因果关系，等等。而在TAMs研究中发现，TAM的不同来源(比如TRM来源和单核细胞来源)可能导致其对耗竭或调节干预表现出不同的敏感性，在治疗中或许就需要双重TAM靶向策略以提高免疫治疗效果。同时，人和小鼠中不同表征的巨噬细胞分化阶段的比例在两个物种之间有很大的差异，也会影响对于临床疗效的判断。cavity macrophages：人vs鼠组织驻留的网膜腔巨噬细胞是TAM的重要来源之一，在卵巢癌、肝纤维化等实体瘤TME的形成中起到重要作用。大多数小鼠网膜巨噬细胞特征是GATA6+和CXCL1、SELP等其他相关基因的表达。体内动态平衡中，小鼠腹膜巨噬细胞存在两种不同的巨噬细胞群。（一）大腹腔巨噬细胞(LCM)LCM是更主要的巨噬细胞群，仅存在于腹膜、胸膜和心包腔的腔液中。表征：LCM表达F4/80hi CD115+ ICAM2+，来源于胚胎前体，依赖转录因子GATA6进行发育和维持。在没有GATA6的情况下，LCM会下调CD73，并上调CD206和LYVE1等。功能：作为对炎症或损伤的反应，LCM通过聚集在扰动的空洞表面或纤维蛋白凝块内来帮助遏制早期感染发生。 （二）小腹腔巨噬细胞(SCM)表征：SCM表达F4/80lo MHCII+，超过75%的SCM还表达CD226。该亚群起源于类似于单核细胞的CCR2依赖性前体，其发育程序依赖于转录因子IRF4。功能：以前一般将其归类为M1类巨噬细胞。但是其中部分群体的同时表达巨噬细胞和DC的混合功能特征。LCM和SCM都表达CD115和和CD11b。在人体中：尽管人体中同样存在GATA6+的腹膜巨噬细胞，但是数量非常少。相对地，人体中数量丰富的CCR2+或GLUL+巨噬细胞则没有在小鼠中发现明显对应的亚群。CCR2+也代表了与单核细胞浸润有关的早期分化阶段。若要对应，人体表达GATA6+的巨噬细胞亚群为TIMD4+亚群，和小鼠中的GATA6+ LCM1亚群一样表达SELP信使RNA。而表达相同RNA的其他巨噬细胞还包括：MRC1+ LYVE1+ CD163+ 巨噬细胞；GLUL+ CD163++ FABP5+ 巨噬细胞；Marco+ 巨噬细胞；IL1B+ 巨噬细胞；干扰素刺激基因(ISG)+ 巨噬细胞；CCR2+ 巨噬细胞；以及CD1C+CD14+ 巨噬细胞。其中，小鼠中存在和MRC1+LYVE1+CD163+ 巨噬细胞同样表达和起源的亚群，但是比例比人体内更少。这代表着人腹腔巨噬细胞的分化周期相对于小鼠来说，更多存在于GATA6表达之前的分化阶段，许多巨噬细胞似乎在GATA6表达之前的阶段停滞或在表达后不久死亡。而CD1C+CD14+ 巨噬细胞则和小鼠F4/80lo MHCII+ SCM具有相似的特征。人CD1C+ 细胞在小鼠中可对应CD226+ 干细胞。在人体中，CD1C+细胞相对丰富，可分为：CD1C+ CD14+亚群：表达编码CD16、CD115、CD63、CD163和巨噬细胞相关基因；CD1C+ CD14- 亚群：表达一些DC经典表征基因，包括LTB、肥大细胞特异性表征FCER1A、CD37和CD1E。同时，CD1c+人腹膜单核巨噬细胞群中同样存在具有混合巨噬细胞和DC特征的CD1c+ cDC2和CD1c+ CD14+ CD64+ CD226+ 细胞亚群。小结巨噬细胞的亚群表征多样，在人体中的研究也尚待继续完善。F4/80、Ly6G和Ly6C等小鼠特异性分子标记物在人巨噬细胞中不表达，为研究中在小鼠模型和人体之间进行翻译带来了困难。更准确的亚群特征对应研究或提高TME相关免疫疗法的可行性。参考文献：1.Han, J., Gallerand, A., Erlich, E.C. et al. Human serous cavity macrophages and dendritic cells possess counterparts in the mouse with a distinct distribution between species. Nat Immunol (2023). https://doi-org.libproxy1.nus.edu.sg/10.1038/s41590-023-01688-72.Andrea Vogel, Thomas Weichhart,Tissue-resident macrophages — early passengers or drivers in the tumor niche?,Current Opinion in Biotechnology,Volume 83,2023,102984,ISSN 0958-1669,https://doi-org.libproxy1.nus.edu.sg/10.1016/j.copbio.2023.102984.3.Zhi Wang, Kailei Du, Nake Jin, Biao Tang, Wenwu Zhang,Macrophage in liver Fibrosis: Identities and mechanisms,International Immunopharmacology,Volume 120,2023,110357,ISSN 1567-5769,https://doi-org.libproxy1.nus.edu.sg/10.1016/j.intimp.2023.110357.

*仅供医学专业人士阅读参考TIM-3在多种免疫细胞上广泛表达，与慢性病毒感染以及肿瘤浸润T细胞的终末分化、功能耗竭密切相关，已被证明是一种极具潜力的免疫检查点靶点。抑制TIM-3能够逆转T细胞耗竭并促进小鼠的肿瘤消退，与PD-1抑制剂联合使用时可增强PD-1抑制剂的抗肿瘤作用。但是到目前为止，抗TIM-3抗体的临床转化表现不佳，也没有报道具有细胞活性的TIM-3小分子抑制剂。近日，山东大学齐鲁医学院的马春红、李春阳、刘新泳等人的最新研究成果发表在《科学转化医学》期刊上。在筛选超过20万种化合物后，研究团队成功鉴定出一种靶向TIM-3的小分子化合物，ML-T7。体内外实验结果显示，ML-T7能够增强CD8阳性T细胞和CAR-T细胞的抗肿瘤活性，单独治疗可直接抑制小鼠肿瘤进展，与PD-1抑制剂具有协同作用[1]。论文首页截图TIM-3是一种膜蛋白，它的IgV结构域存在一个独特的结构，被称为FG-CC'裂缝，是其配体磷脂酰丝氨酸 （PtdSer）和癌胚抗原相关细胞黏附分子1（CEACAM1）的高度保守结合位点。在这项研究中，研究团队通过虚拟筛选结合功能筛选的策略，从Specs数据库的204380种小分子化合物中识别出ML-T7。利用表面等离子体共振（SRP）等技术和分子动力学、晶体结构分析，研究团队证实ML-T7能够特异性地靶向TIM-3的FG-CC'裂缝，而且与TIM-3的亲和力高于PtdSer、CEACAM1。ML-T7通过FG-CC'裂缝与TIM-3稳定结合，破坏TIM-3与PtdSer、CEACAM1的结合和相互作用。ML-T7的筛选和鉴定体外实验和小鼠模型实验结果显示，通过靶向TIM-3，ML-T7能够促进CD8阳性细胞毒性T细胞的存活、增殖和抗肿瘤活性，防止功能耗竭。ML-T7治疗后，CD8阳性细胞毒性T细胞中的IL-2/STAT5信号通路上调，IFN-γ、TNF-α、IL-2等效应因子以及活化标志物（CD25和CD69）、干细胞特性相关细胞因子（TCF1）表达水平提高；相反，PD-1和CTLA-4等耗竭标志物的表达下降，终末耗竭T细胞比例下调。来自先天免疫系统的自然杀伤细胞、树突状细胞，它们的功能同样受到TIM-3的负调节。特别是在树突状细胞中，还有TIM-4的特异性高表达。研究团队发现，ML-T7不仅能提高自然杀伤细胞的杀伤活性，还通过作用于TIM-3和TIM-4，促进树突状细胞的成熟和提升其抗原呈递能力。利用多种原发性肝细胞癌小鼠模型，他们对ML-T7的治疗效果进行观察。结果显示，与对照组相比，每两天腹腔注射一次20mg/kg或50mg/kg剂量的ML-T7治疗，能够显著抑制肿瘤生长，并延长小鼠生存时间，减轻肿瘤微环境的免疫抑制性。进一步研究表明，20mg/kg ML-T7单独治疗与100mg/kg PD-1抑制剂单独治疗的抗肿瘤活性相近，两者联合使用时具有协同效应，重新激活肿瘤微环境中的CD8阳性T细胞和自然杀伤细胞。采用联合治疗后120天时，50%小鼠存活（3/6只），而采用ML-T7或PD-1抑制剂单独治疗的小鼠几乎没有存活（存活0/6只或1/6只）。与PD-1抑制剂联合治疗效果另外，ML-T7处理能够显著提升CAR-T细胞对肿瘤细胞的细胞毒性，同时诱导CAR-T细胞在过继转移后凋亡减少、增殖能力增强。更重要的是，ML-T7处理有效地克服了CAR-T细胞治疗中的难题，即防止功能耗竭，从而提高CAR-T细胞疗效，其中10μM ML-T7对逆转CAR-T细胞耗竭效果最佳。用于增强CAR-T细胞从安全性来看，ML-T7耐受性良好，每两天腹腔注射一次50mg/kg剂量的ML-T7治疗在小鼠中未导致明显的不良事件。总体来说，这项研究展现了TIM-3小分子抑制剂ML-T7用于肿瘤免疫治疗的巨大潜力。ML-T7不仅单打独斗有一手，还能够强化CAR-T细胞疗法和PD-1抑制剂疗法的抗肿瘤活性，安全有效，值得进一步开发用于临床转化。参考文献：[1]https://www-science-org.libproxy1.nus.edu.sg/doi/10.1126/scitranslmed.adg6752本文作者丨张艾迪