Fine-tuning CXCL12-mediated activities using Beta1-strand binding peptides

摘要 CXCR 4/CXCR 7-CXCL 12信号传导关键地调节免疫和癌细胞功能。我们的工作和 其他人已经确定了趋化因子异源二聚体的存在和潜力，特别是CXCL 4-CXCL 12 与CXCL 12-CXCR 4信号传导的抑制相关，提示新的调节靶向机制。 这些新发现的相互作用（包括CXCL 4-CXCL 12）的生物学后果 具有CXCR 7的异二聚体尚未被研究。此外，CXCL 4-CXCL 12趋化因子异源性趋化因子是否与CXCL 4-CXCL 12趋化因子相关。 二聚化可作为治疗靶点以防止CXCL 12驱动的细胞功能是未知的。 因此，我们将检验CXCL 12 β 1-链结合肽，模拟CXCL 4 与CXCL 12相互作用，严重影响明确描述的CXCL 12-CXCR 4/ CXCR 7驱动信号。具体来说，我们将确定CXCL 12 β 1-链结合的抑制潜力 CXCL 12-CXCR 4/CXCR 7中的肽驱动巨噬细胞和上皮细胞中的信号传导。非- 本研究的重叠特定目标将定义结合特征并优化CXCL 12 β 1- 链结合肽（Aim 1）;并确定CXCL 12的功能性信号转导调节潜力 β 1-链结合肽分别结合到CXCR 4和CXCR 7上（Aim 2）。我们将评估CXCL 12- CXCL 12 β 1-链结合肽异二聚体信号传导至CXCR 4和CXCR 7相关功能 对关键细胞功能的活性，沿着促进稳定CXCL 12的最佳生物物理条件。 CXCL 12 β 1-链结合肽相互作用和特异性CXCL 12 β 1-链结合的潜力 CXCL 12-CXCR 4/CXCR 7信号转导和调节CXCL 12驱动的细胞功能的肽。 总之，通过完成与完成实验相关的实验收集的数据， 提出的目标将产生对CXCL 12异二聚体信号传导到CXCR 4上的更好理解， CXCR 7和CXCL 12 β 1-链结合肽在阻止改变CXCL 12驱动的 信号和功能。基于这些结果并靶向趋化因子的异嗜性相互作用， 我们的长期目标是对趋化因子的功能有一个基本的了解 异二聚体在趋化因子信号传导中作用及其作为靶点预防疾病进展的潜力。这一领域 该项目将使本科生接触到一个综合和跨学科的研究环境， 扩大生物科学系、物理系和光学科学系的培训机会， 北卡罗来纳州夏洛特大学，一个快速发展的城市机构，旨在加强其 生物医学研究计划。这个项目已经通过PI吸引了许多本科生 和co-I的课堂教学，并将进一步为本科生提供实验室实践经验 研究技术，并介绍他们在生物医学研究的职业生涯。学生们将参加一个P-to- 在各级进行同侪培训，包括强调取得职业成功所需的技能，如团队合作 和沟通。

ABSTRACT The CXCR4/CXCR7-CXCL12 signaling critically modulate immune and cancer cell functions. Our work and others have established the presence and the potential of chemokine heterodimers especially CXCL4-CXCL12 associated with an inhibition of CXCL12-CXCR4 signaling suggesting a new regulatory targetable mechanism. The biological consequences of these newly discovered interactions including of CXCL4-CXCL12 heterodimers with CXCR7 have not been studied yet. Further, whether CXCL4-CXCL12 chemokine hetero- dimerization may serve as a therapeutic target to prevent CXCL12-driven cell function is unknown. Therefore, we will test the hypothesis that CXCL12 ß1-strand binding peptides, mimicking the CXCL4 interface with CXCL12, critically affect signaling and biological activities in well-delineated CXCL12-CXCR4/ CXCR7 driven signaling. Specifically, we will determine the inhibiting potential of CXCL12 ß1-strand binding peptides in the CXCL12-CXCR4/CXCR7 driven signaling in macrophages and epithelial cells. The non- overlapping specific aims of the study will define binding characteristics and optimize the CXCL12 ß1- strand binding peptides (Aim 1); and determine the functional signaling modulating potential of CXCL12 ß1-strand binding peptides onto CXCR4 and CXCR7 (Aim 2), respectively. We will assess the CXCL12- CXCL12 ß1-strand binding peptide heterodimer signaling onto CXCR4 and CXCR7 associated functional activities on key cell functions, along with the optimal biophysical conditions promoting stable CXCL12- CXCL12 ß1-strand binding peptide interactions and the potential of specific CXCL12 ß1-strand binding peptides to inhibit CXCL12-CXCR4/CXCR7 signaling and modulate CXCL12-driven cell functions. Together, the data gathered through the completion of the experiments associated with the completion of the proposed aims will yield a better understanding of the CXCL12 heterodimer signaling onto CXCR4 and CXCR7 and the potential of CXCL12 ß1-strand binding peptides in preventing altering CXCL12-driven signaling and functions. Building on these results and targeting heterophilic interactions of chemokines, our long-term goal is to develop a fundamental understanding of the functions of chemokine heterodimers in chemokine signaling and their potential as target to prevent disease progression. This AREA project will expose undergraduate students to an integrative and cross-disciplinary research environment by extending training opportunities in the Departments of Biological Sciences and Physics and Optical Sciences at the University of North Carolina Charlotte, a rapidly-growing urban institution that seeks to strengthen its biomedical research program. This project has already attracted many undergraduate students through the PI’s and co-I’s classroom teaching and will further provide undergraduates a hands-on experience with laboratory research techniques and introduce them to a career in biomedical research. Students will participate in peer-to- peer training at all levels, including an emphasis on skills needed for professional success such as teamwork and communication.