Natural Cytotoxicity Receptors NKp30, NKp44 and NKp46 Bind to Different Heparan Sulfate/Heparin Sequences

Abstract

Natural Killer (NK) cells recognize and destroy tumors and virus-infected cells in an antibody-independent manner. The regulation of NK cells is mediated by activating and inhibiting receptors on the NK cell surface. One important family of activating receptors is the natural cytotoxicity receptors (NCRs) which include NKp30, NKp44 and NKp46. The NCRs initiate tumor targeting by recognition of heparan sulfate on cancer cells. This study aims to elucidate heparan sulfate structural motifs that are important for NCR binding. Microarray and surface plasmon resonance experiments with a small library of heparan sulfate/heparin oligosaccharides helped to clarify the binding preferences of the three NCRs. We demonstrate that the NCRs interact with highly charged HS/heparin structures, but differ in preferred modification patterns and chain lengths. The affinity of NKp30 and NKp44 for synthetic HS/heparin is approximately one order of magnitude higher than the affinity of NKp46. We further show the relevance of synthetic HS/heparin for the binding of NCRs to tumor cells and for NCR-mediated activation of natural killer cells. In conclusion, NCRs recognize different microdomains on heparan sulfate with different affinities.

Nidogen-1 is a novel extracellular ligand for the NKp44 activating receptor

“…For example, NKp44 appears to differently modulate NK cell function by cis- or trans-interactions with heparan-sulphate proteoglycans (present at the NK or target cell surface). 27,28 In addition, this receptor has been reported to transduce inhibitory signals upon interaction with Proliferating Cell Nuclear Antigen (PCNA). 29,30 NKp30 triggers cytotoxicity and cytokine release upon binding B7H6 or BAT3 at the cell surface.…”

Synthetic di-sulfated iduronic acid attenuates asthmatic response by blocking T-cell recruitment to inflammatory sites

“…Glycan Microarray. Microarrays were fabricated as previously reported (39). Microarray slide was incubated with 100 μL (5 μg) of rhCCL20 (R&D Systems) in HBS-N containing 0.01% Tween 20 for 1 h at room temperature under mild shaking, washed three times with HBS-N, and dried by centrifugation.…”

NCR2 (natural cytotoxicity triggering receptor 2)

“…Recognition of tumor cells is partially mediated through charged based binding of NKp44 with heparin sulfate proteoglycans (HSPG) on the surface of tumor cells (Hershkovitz et al, 2007). Specifically, the 2-Osulfation of iduronic acid and N-acetylation of glucosamine on HSPGs are important for interaction with NKp44 (Hecht et al, 2009). Glycans containing α2,6-N¬-acetylneuraminic acid are also recognized on the surface of cancer cells by NKp44 (Ito et al, 2012).…”