Varied levels of reactivity by different E-selectin/Fc constructs with cutaneous lymphocyte-associated antigen (CLA)(+) CD4(+) T cells

An adhesion based approach for the detection of esophageal cancer

Esophageal cancer has a 5 year survival rate of ∼20%. This dismal prognosis is due, in part, to the fact that esophageal cancer often presents at a late stage. Thus, there is a critical need for assays that enable the early detection of cancerous tissue within the esophagus. The luminal surface of the esophagus expresses signature molecule(s) at sites of transformation providing an avenue for the development of in situ assays that detect neoplastic growth within the esophagus. An attractive approach, receiving increased attention, is the endoscopic administration of particles conjugated with ligands to signature molecules present on transforming tissue. Detection of the particles within the esophagus, post-washing, would indicate the presence of the signature molecule and thus transforming tissue. In this work, we utilized cancerous and normal esophageal cells to provide in vitro proof of principle for this approach utilizing ligand-conjugated microspheres and demonstrate the need, and provide the framework for, engineering this technology. Specifically, the study (i) reveals selective increased expression of signature molecules on cancerous esophageal cells relative to normal cells; (ii) demonstrates selective binding of ligand-conjugated microspheres to cancerous esophageal cells relative to normal cells; (iii) demonstrates that the selective recognition of cancerous, relative to normal esophageal cells, is highly dependent on the biophysical design of the assay; and (iv) advocates utilizing the knowledge from the field of cell adhesion as a guide for the effective development of ligand-conjugated particle-based schemes that seek to detect esophageal oncogenesis in situ.

Dynamic biochemical tissue analysis detects functional selectin ligands on human cancer tissues

Cell adhesion mediated by selectins (expressed by activated endothelium, activated platelets, and leukocytes) binding to their resepective selectin ligands (expressed by cancer cells) may be involved in metastasis. Therefore, methods of characterizing selectin ligands expressed on human tissue may serve as valuable assays. Presented herein is an innovative method for detecting functional selectin ligands expressed on human tissue that uses a dynamic approach, which allows for control over the force applied to the bonds between the probe and target molecules. This new method of tissue interrogation, known as dynamic biochemical tissue analysis (DBTA), involves the perfusion of molecular probe-coated microspheres over tissues. DBTA using selectin-coated probes is able to detect functional selectin ligands expressed on tissue from multiple cancer types at both primary and metastatic sites.

Cutaneous lymphocyte-associated antigen (CLA) T cells up-regulate P-selectin ligand expression upon their activation

Memory T cells expressing CLA occur in humans and accumulate in normal and inflamed skin. These cells uniformly bind to the vascular adhesion molecule E-selectin, yet only a subset binds to P-selectin. The latter cells are distinguished by the mAb CHO-131, and are enriched in psoriasis lesions. Activated T cells up-regulate CLA expression, but little is currently known about their binding to P-selectin. We observed that CLA(+) CD4(+) T cells derived from stimulated naive T cells uniformly express the CHO-131 epitope. This occurred as well upon the restimulation of memory CLA(+) CD4(+) T cells. The latter cells also expressed higher levels of PSGL-1 modified by P-selectin glycan ligands; C2GlcNAcT-1 mRNA, a glycosyltransferase critical for such glycan synthesis; and more uniformly bound to P-selectin. Our findings thus indicate that unlike memory CLA(+) CD4(+) T cells, when activated these cells can broadly bind to P-selectin, suggesting a more diverse tissue trafficking capacity.

The E-selectin ligand basigin/CD147 is responsible for neutrophil recruitment in renal ischemia/reperfusion

E-selectin and its ligands are essential for extravasation of leukocytes in inflammation. Here, we report that basigin (Bsg)/CD147 is a ligand for E-selectin that promotes renal inflammation in ischemia/reperfusion. Compared with wild-type mice, Bsg-deficient (Bsg(-/-)) mice demonstrated striking suppression of neutrophil infiltration in the kidney after renal ischemia/reperfusion. Although E-selectin expression increased similarly between the two genotypes, Bsg(-/-) mice exhibited less renal damage, suggesting that Bsg on neutrophils contribute to renal injury in this model. Neutrophils expressed Bsg with N-linked polylactosamine chains and Bsg(-)(/)(-) neutrophils showed reduced binding to E-selectin. Bsg isolated from HL-60 cells bound to E-selectin, and tunicamycin treatment to abolish N-linked glycans from Bsg abrogated this binding. Furthermore, Bsg(-)(/)(-) neutrophils exhibited reduced E-selectin-dependent adherence to human umbilical vein endothelial cells in vitro. Injection of labeled neutrophils into mice showed that Bsg(-)(/)(-) neutrophils were less readily recruited to the kidney after renal ischemia/reperfusion than Bsg(+/+) neutrophils, regardless of the recipient's genotype. Taken together, these results indicate that Bsg is a physiologic ligand for E-selectin that plays a critical role in the renal damage induced by ischemia/reperfusion.

Two different homing pathways involving integrin β7 and E-selectin significantly influence trafficking of CD4 cells to the genital tract following Chlamydia muridarum infection

PROBLEM

Chlamydia trachomatis causes STI and reproductive dysfunction worldwide which is not preventable with antibiotics. Identifying a population of endocervical T cells to target in vaccine development would enhance efficacy.

METHOD OF STUDY

Trafficking of murine CD4+ lymphocytes to Chlamydia muridarum infected genital tract (GT) tissue in vivo was measured using adoptive transfer studies of fluorescent CD4+ T cells from integrin β7-/- mice or mice which lack E-selectin on endothelial cells.

RESULTS

Murine in vivo migration studies showed that lack of α4β7 or E-selectin significantly reduced trafficking of CD4 T cells to the GT of mice infected with C. muridarum.

CONCLUSION

CD4+ T cells use at least two different adhesive mechanisms involving an integrin of the mucosal homing pathway and selectin pathway to accumulate in the GT during C. muridarum infection.