RESUMO
Snake venoms contain an astounding variety of different proteins. Among them are numerous C-type lectin family members, which are grouped into classical Ca2+- and sugar-binding lectins and the non-sugar-binding snake venom C-type lectin-related proteins (SV-CLRPs), also called snaclecs. Both groups share the robust C-type lectin domain (CTLD) fold but differ in a long loop, which either contributes to a sugar-binding site or is expanded into a loop-swapping heterodimerization domain between two CLRP subunits. Most C-type lectin (-related) proteins assemble in ordered supramolecular complexes with a high versatility of subunit numbers and geometric arrays. Similarly versatile is their ability to inhibit or block their target molecules as well as to agonistically stimulate or antagonistically blunt a cellular reaction triggered by their target receptor. By utilizing distinct interaction sites differentially, SV-CLRPs target a plethora of molecules, such as distinct coagulation factors and receptors of platelets and endothelial cells that are involved in hemostasis, thrombus formation, inflammation and hematogenous metastasis. Because of their robust structure and their high affinity towards their clinically relevant targets, SV-CLRPs are and will potentially be valuable prototypes to develop new diagnostic and therapeutic tools in medicine, provided that the molecular mechanisms underlying their versatility are disclosed.
Assuntos
Lectinas Tipo C/química , Venenos de Serpentes/química , Animais , Humanos , Conformação ProteicaRESUMO
Objective:In order to get recombinant protein OCILRP 2-Fc and anti-OCILRP2 antibody for further study of OCILRP2.Methods:Eukaryotic expression vector pIg-CD5-OCILRP2 which fused with extracellular domain of OCILRP 2 and human IgG1 Fc fragment was constructed.G418 was used for stable expression cell strain after pIg-CD5-OCILRP2 transfected into CHO cells.Recombinant protein OCILRP 2-Fc purified from CHO cell supernatant was used to immunize rabbit and anti-OCILRP2 polyclonal antibody was purified from rabbit serum by using protein G column.Results: ELISA data showed that we got a high-titer anti-serum and anti-OCILRP2 antibody purified from the rabbit serum.Western blot indicated this antibody could specifically bind to OCILRP 2-Fc and OCILRP2 in NIH/3T3 lysate.OCILRP2 expression in murine bone marrow derived dendritic cells ( DC) was detected by this polyclonal antibody ,too.Compared to immature DC ,OCILRP2 expression was elevated in LPS induced-mature DC.Conclusion: This study has offered an available tool and provided a clue for further study of the roles of OCILRP 2 in immune response.
RESUMO
Recognition of glycosylation patterns is one of the basic features of innate immunity. Ability of C-type lectin-like receptors such as NKR-P1 to bind saccharide moieties has become recently a controversial issue. In the present study, binding assay with soluble fluorescently labeled recombinant rat NKR-P1A and mouse NKR-P1C proteins revealed apparently no affinity to the various neoglycoproteins. Lack of functional linkage between NKR-P1 and previously described saccharide binder was supported by the fact, that synthetic N-acetyl-D-glucosamine octabranched dendrimer on polyamidoamine scaffold (GN8P) did not change gene expression of NKR-P1 isoforms in C57BL/6 and BALB/c mice divergent in the NK gene complex (both in vitro and in vivo). Surprisingly, N-acetyl-D-glucosamine-coated tetrabranched polyamido-amine dendrimer specifically binds to NKT cells and macrophages but not to NK cells (consistently with changes in cytokine patterns). Despite the fact that GN8P has been tested as an immunomodulator in anti-cancer treatment animal models for many years, surprisingly no changes in cytokine profiles in serum relevant to anti-cancer responses using B16F10 and CT26 harboring mouse strains C57BL/6 and BALB/c are observed. Our results indicate possible indirect involvement of NK cells in GN8P mediated immune responses.
