Clinical efficacy of chimeric antigen receptor (CAR) T cells against pediatric osteosarcoma (OS) has been limited. One strategy to improve efficacy may be to drive chemokine-mediated homing of CAR T cells to tumors. We sought to determine the primary chemokines secreted by OS and evaluate the efficacy of B7-H3.CAR T cells expressing the cognate receptors.
We developed a pipeline to identify chemokines secreted by OS by correlating RNA-seq data with chemokine protein detected in media from fresh surgical specimens. We identified CXCR2 and CXCR6 as promising receptors for enhancing CAR T-cell homing against OS. We evaluated the homing kinetics and efficiency of CXCR2- and CXCR6.T cells and homing, cytokine production, and antitumor activity of CXCR2- and CXCR6.B7-H3.CAR T cells in vitro and in vivo.
T cells transgenically expressing CXCR2 or CXCR6 exhibited ligand-specific enhanced migration over T cells modified with nonfunctional control receptors. Differential homing kinetics were observed, with CXCR2.T-cell homing quickly and plateauing early, whereas CXCR6.T cells took longer to home but achieved a similar plateau. When expressed in B7-H3.CAR T cells, CXCR2- and CXCR6 modification conferred enhanced homing toward OS in vitro and in vivo. CXCR2- and CXCR6-B7-H3.CAR-treated mice experienced prolonged survival in a metastatic model compared with B7-H3.CAR T-cell-treated mice.
Our patient-based pipeline identified targets for chemokine receptor modification of CAR T cells targeting OS. CXCR2 and CXCR6 expression enhanced the homing and anti-OS activity of B7-H3.CAR T cells. These findings support clinical evaluation of CXCR-modified CAR T cells to improve adoptive cell therapy for patients with OS.
©2024 The Authors; Published by the American Association for Cancer Research.

Despite aggressive clinical protocol, all glioblastoma (GBM) recur at the initial site within the irradiated peritumoral microenvironment. Whereas irradiated microenvironment has been recently proposed to accelerate GBM relapse, molecular and cellular mechanisms remain unknown. Here, using relevant in vitro and in vivo models, we decipher how radiation-induced endothelial senescence drives the emergence of aggressive GBM cells. Secretome (SASP) of radiation-induced senescent (RIS) endothelium enhances genomic instability and intratumoral heterogeneity in irradiated GBM cells. In-depth molecular studies revealed that CXCL5 and CXCL8, from the SASP, activate CXCR2 receptor on tumor cells leading to increased DNA hyper-replication, micronuclei formation and aneuploidy. Importantly, through CXCL5/8-CXCR2 axis activation, this SASP increases GBM aggressiveness in vivo . Both chemokines were detected in relapsing, but not primary, GBM biopsies and positively correlated with worst patient outcome. In conclusion, we identify new molecular and preclinical insights of relapsing GBM aggressiveness where RIS vascular niches fuel aggressive tumor emergence.

CXCR1 and CXCR2 signaling play a critical role in neutrophil migration, angiogenesis, and tumorigenesis and are therefore an attractive signaling axis to target in a variety of indications. In human, a total of seven chemokines signal through these receptors and comprise the ELR+CXC chemokine family, so named because of the conserved ELRCXC N-terminal motif. To fully antagonize CXCR1 and CXCR2 signaling, an effective therapeutic should block either both receptors or all seven ligands, yet neither approach has been fully realized clinically. In this work, we describe the generation and characterization of LY3041658, a humanized monoclonal antibody that binds and neutralizes all seven human and cynomolgus monkey ELR+CXC chemokines and three of five mouse and rat ELR+CXC chemokines with high affinity. LY3041658 is able to block ELR+CXC chemokine-induced Ca2+ mobilization, CXCR2 internalization, and chemotaxis in vitro as well as neutrophil mobilization in vivo without affecting other neutrophil functions. In addition to the in vitro and in vivo activity, we characterized the epitope and structural basis for binding in detail through alanine scanning, crystallography, and mutagenesis. Together, these data provide a robust preclinical characterization of LY3041658 for which the efficacy and safety is being evaluated in human clinical trials for neutrophilic skin diseases.

Wound healing represents a dynamic process involving directional migration of different cell types. Chemokines, a family of chemoattractive proteins, have been suggested to be key players in cell-to-cell communication and essential for directed migration of structural cells. Today, the role of the chemokine network in cutaneous wound healing is not fully understood. Unraveling the chemokine-driven communication pathways in this complex process could possibly lead to new therapeutic strategies in wound healing disorders.
We performed a systematic, comprehensive time-course analysis of the expression and function of a broad variety of cytokines, growth factors, adhesion molecules, matrixmetalloproteinases and chemokines in a murine cutaneous wound healing model.
Strikingly, chemokines were found to be among the most highly regulated genes and their expression was found to coincide with the expression of their matching receptors. Accordingly, we could show that resting and activated human primary keratinocytes (CCR3, CCR4, CCR6, CXCR1, CXCR3), dermal fibroblasts (CCR3, CCR4, CCR10) and dermal microvascular endothelial cells (CCR3, CCR4, CCR6, CCR8, CCR9, CCR10, CXCR1, CXCR2, CXCR3) express a distinct and functionally active repertoire of chemokine receptors. Furthermore, chemokine ligand-receptor interactions markedly improved the wound repair of structural skin cells in vitro.
Taken together, we here present the most comprehensive analysis of mediators critically involved in acute cutaneous wound healing. Our findings suggest therapeutic approaches for the management of wound closure by targeting the chemokine network.

The focus of this study was to determine which chemokine receptors are present on oral fibroblasts and whether these receptors influence proliferation, migration, and/or the release of wound healing mediators. This information may provide insight into the superior wound healing characteristics of the oral mucosa. The gingiva fibroblasts expressed 12 different chemokine receptors (CCR3, CCR4, CCR6, CCR9, CCR10, CXCR1, CXCR2, CXCR4, CXCR5, CXCR7, CX3CR1, and XCR1), as analyzed by flow cytometry. Fourteen corresponding chemokines (CCL5, CCL15, CCL20, CCL22, CCL25, CCL27, CCL28, CXCL1, CXCL8, CXCL11, CXCL12, CXCL13, CX3CL1, and XCL1) were used to study the activation of these receptors on gingiva fibroblasts. Twelve of these fourteen chemokines stimulated gingiva fibroblast migration (all except for CXCL8 and CXCL12). Five of the chemokines stimulated proliferation (CCL5/CCR3, CCL15/CCR3, CCL22/CCR4, CCL28/CCR3/CCR10, and XCL1/XCR1). Furthermore, CCL28/CCR3/CCR10 and CCL22/CCR4 stimulation increased IL-6 secretion and CCL28/CCR3/CCR10 together with CCL27/CCR10 upregulated HGF secretion. Moreover, TIMP-1 secretion was reduced by CCL15/CCR3. In conclusion, this in-vitro study identifies chemokine receptor-ligand pairs which may be used in future targeted wound healing strategies. In particular, we identified the chemokine receptors CCR3 and CCR4, and the mucosa specific chemokine CCL28, as having an predominant role in oral wound healing by increasing human gingiva fibroblast proliferation, migration, and the secretion of IL-6 and HGF and reducing the secretion of TIMP-1.
© 2017 The Authors. Journal of Cellular Physiology Published by wiley periodicals, Inc.