Serum stimulation of CCR7 chemotaxis due to coagulation factor XIIa-dependent production of high-molecular-weight kininogen domain 5

Abstract

Chemokines and their receptors play a critical role in immune function by directing cell-specific movement. C-C chemokine receptor 7 (CCR7) facilitates entry of T cells into lymph nodes. CCR7-dependent chemotaxis requires either of the cognate ligands C-C chemokine ligand 19 (CCL19) or CCL21. Although CCR7-dependent chemotaxis can be augmented through receptor up-regulation or by increased chemokine concentrations, we found that chemotaxis is also markedly enhanced by serum in vitro. Upon purification, the serum cofactor activity was ascribed to domain 5 of high-molecular-weight kininogen. This peptide was necessary and sufficient for accelerated chemotaxis. The cofactor activity in serum was dependent on coagulation factor XIIa, a serine protease known to induce cleavage of high-molecular-weight kininogen (HK) at sites of inflammation. Within domain 5, we synthesized a 24-amino acid peptide that could recapitulate the activity of intact serum through a mechanism distinct from up-regulating CCR7 expression or promoting chemokine binding to CCR7. This peptide interacts with the extracellular matrix protein thrombospondin 4 (TSP4), and antibodies to TSP4 neutralize its activity. In vivo, an HK domain 5 peptide stimulated homing of both T and B cells to lymph nodes. A circulating cofactor that is activated at inflammatory foci to enhance lymphocyte chemotaxis represents a powerful mechanism coupling inflammation to adaptive immunity.

Immune and Stroma Related Genes in Breast Cancer: A Comprehensive Analysis of Tumor Microenvironment Based on the Cancer Genome Atlas (TCGA) Database

“…Researchers have found that CCR7 is highly expressed on human B cells, expanded T cells instead of naïve T cells (38) and dendritic cells (39) and its expression on peripheral T cells was positively related to the chemotactic migration of T cells to CCL19 and CCL21 (40). On the other hand, CCR7 mediated chemotaxis required the existence of CCL19 or CCL21 (41). In vitro experiment indicated that recombinant CCL19 showed potent chemotactic activity for T-cells and Bcells but not for granulocytes and monocytes.…”

Design, Synthesis, and Evaluation of a Diazirine Photoaffinity Probe for Ligand-Based Receptor Capture Targeting G Protein–Coupled Receptors

“…Conceptually, the target can then be identified through MS analysis. Although this elegant ligand-based receptor-capture (LRC) strategy has resulted in successful identification of certain membrane receptors (Li et al, 2016, 2018; Ponda and Breslow, 2016), identification can only occur for receptors carrying an N-linked glycan in close proximity to the ligand-binding site. To overcome this glycan dependency, others have recently developed ligand-derived probes harboring photoaffinity labels to capture target receptors (Blex et al, 2017; Thomas et al, 2017).…”

CDX2 expression and perioperative patient serum affects the adhesion properties of cultured colon cancer cells

“…In this study, we established an in vitro method for measuring the effect of perioperative factors on the adhesion ability of the LS174T colon cancer cell line using serum from patients undergoing colon cancer surgery. Commonly used methods for cell adhesion assays typically include staining attached cells and using fluorescence for endpoint measurements [39][40][41], but by using the method developed in this paper, it is possible to monitor real-time cell adhesion for the entire adhesion period. While this method does not allow us to distinguish between initial sedimentation, cell attachment, cell spreading and stable cell adhesion, the mentioned are all part of the passive cell adhesion process [42].…”