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

摘要 CXCR4/CXCR7-CXCL12信号对免疫和癌细胞功能起着重要的调节作用。我们的工作和 其他人已经证实了趋化因子异二聚体的存在和潜力，特别是CXCL4-CXCL12 与抑制CXCL12-CXCR4信号有关，提示了一种新的调控靶向机制。 包括CXCL4-CXCL12在内的这些新发现的相互作用的生物学后果 含CXCR7的杂二聚体还没有被研究过。此外，CXCL4-CXCL12趋化因子是否异源- 二聚化可能作为阻止CXCL12驱动的细胞功能未知的治疗靶点。 因此，我们将检验CXCL12？1-链结合多肽的假设，模拟CXCL4 CXCL12与CXCL12的接口，对CXCL12-CXCR4/中的信号和生物活性有重要影响 CXCR7驱动的信令。具体地说，我们将确定CXCL12？1链结合的抑制潜力 CXCL12-CXCR4/CXCR7中的多肽驱动巨噬细胞和上皮细胞的信号转导。非-- 研究的重叠的特定目标将定义结合特征并优化CXCL12？1- 链结合多肽(Aim 1)；并测定CXCL12的功能信号调制潜力 ？单链结合多肽分别与CXCR4和CXCR7(目标2)结合。我们将评估CXCL12- CXCL12？1-链结合肽异二聚体信号转导CXCR4和CXCR7相关功能 关键细胞功能的活动，以及促进稳定CXCL12的最佳生物物理条件- CXCL12？1-链结合肽的相互作用和特异性CXCL12？1-链结合的潜力 抑制CXCL12-CXCR4/CXCR7信号转导和调节CXCL12驱动的细胞功能的多肽。 总而言之，通过完成与完成 建议的AIMS将更好地理解CXCL12异二聚体在CXCR4和CXCR4上的信号传递 CXCR7及CXCL12？1链结合肽在防止CXCL12驱动的改变中的作用 信令和功能。在这些结果的基础上，并针对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 趋化因子信号转导中的异源二聚体及其作为预防疾病进展靶点的潜力。这一地区 该项目将通过以下方式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 北卡罗来纳大学夏洛特分校，一所快速发展的城市机构，寻求加强其 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与实验室的实践体验 研究技术，并介绍他们在生物医学研究的职业生涯。学生将参与点对点的 所有级别的同行培训，包括强调专业成功所需的技能，如团队合作 和交流。

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.