GenScript Biotech

Recombinant CHO-K1 cells stably overexpress Homo sapiens programmed death-ligand 1 (PD-L1) on the cell surface. The surface expression is validated by FACS analysis. This cell line is recommended for cell-based binding assay to screen antibodies against PD-L1 or to measure binding affinity between PD-L1 and anti-PD-L1 antibodies.

Programmed cell death 1 ligand 2 (PD-L2) is a protein that in humans is encoded by the PDCD1LG2 gene. PDCD1LG2 has also been designated as CD273 (cluster of differentiation 273). Inhibitory molecules of the B7/CD28 family play a key role in the induction of immune tolerance in the tumor microenvironment. The programmed death-1 receptor (PD-1), with its ligands PD-L1 and PD-L2, constitutes an important member of these inhibitory pathways. PD-L2 expression was initially thought to be restricted to antigen-presenting cells such as macrophages and dendritic cells (DCs). PD-L2 expression can be induced on a wide variety of other immune cells and nonimmune cells depending on microenvironmental stimuli.

The prolactin releasing hormone receptor PRLHR also named PrRP receptor is a G-protein coupled receptor that binds the prolactin releasing hormone. RT-PCR analysis showed expression of PRLHR in the human brain, pituitaries, normal portions of adrenal glands and various tumor tissues. Northern blot analysis showed high expression of PRLHR only in tumor tissues of pheochromocytomas, indicating that PRLHR expression is high in pheochromocytomas. The present study has shown that PRLHR mRNA was widely expressed in the brain tissues, pituitaries, adrenal glands and various tumors. The high expression of PRLHR receptor in pheochromocytomas suggests potential pathophysiological roles of PRLHR in these tumors

The platelet-activating factor (PAF) receptor (PTAFR) is a G protein coupled receptor that signals through multiple pathways and mediates several cellular responses including cell motility, smooth muscle contraction, and releases of cytokine and leukotriene (Stafforini et al., 2003). In humans, various diseases have been associated with PAF, such as allergic asthma, endotoxic shock, atherosclerosis and psoriasis.

Parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor (PTHR1) is a G protein coupled receptor which mediates the actions of both amino-terminal PTH and PTHrP fragments. The most abundant expression of PTHR1 is found in renal tubular cells and in osteoblasts, where the PTH/PTHrP receptor mediates the endocrine actions of PTH, and in prehypertrophic chondrocytes of the metaphyseal growth plate, where it mediates the autocrine/paracrine actions of PTHrP. Intact PTH (PTH 1-84) is compounded by a peptide of 84 amino acids (AA), the amino-terminal sequence, constituted by the first 34 AA (N-terminal structure), is necessary for its action.

Recombinant CHO-K1 cells stably overexpress human SARS-CoV-2 spike protein on their surface. The surface expression of SARS-CoV-2 spike protein is validated by FACS analysis. This stable cell line product is designed for screening antibodies against the SARS-CoV-2 spike protein, as well as measuring binding affinity and stability of antibody-based biologics that bind with spike protein. GenScript also offers spike protein expressing HEK293T stable cell line (Cat. No. M00804) for SARS-CoV-2 study.

Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biologic effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SST1 receptor is a Gi/Go-coupled GPCR which is expressed in pancreatic islets, pituitary, Cerebellum (Purkinje cells), frontal cortex (pyramidal cells), hippocampus (CA1-4 subfields and some granule cells of the dentate gyrus). It inhibits cAMP accumulation and stimulates tyrosine phosphatase activity, it also can antiproliferation.
GenScript’s SST1-expressing stable cell line was made in CHO-K1/Gqi5 host cell and optimized for calcium assays.

Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biologic effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SST2 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in cerebrum and kidney. Studies showed the involvement of the SST2 receptor in the inhibition of glucagon secretion.

Somatostatin receptors (SSTRs), a family of seven transmembrane (TM) domain G-protein-coupled receptors having five distinct subtypes (termed SSTR1-5), are activated by somatostatin secreted from the nerve and endocrine cells. SSTRs are widely expressed in many tissues, frequently as multiple subtypes that coexist in the same cell. With expressions in a tissue-specific manner, SSTRs are involved in the regulation of secretion of insulin, glucagon, and growth hormone as well as cell growth induced by neuronal excitation in both the central and peripheral nervous systems. The five receptors share common signaling pathways such as the inhibition of adenylyl cyclase, activation of phosphotyrosine phosphatase (PTP), and modulation of mitogen-activated protein kinase (MAPK) through G-protein-dependent mechanisms. Aberrant expression of somatostatin receptors is known to be involved in a large number of human tumors. The human medullary thyroid carcinoma cell line TT expresses all SSTR subtypes. SSTR3 mRNA is detected in the brain and pancreatic islets. SSTR3 uniquely triggers PTP-dependent apoptosis accompanied by the activation of p53 and pro-apoptotic protein Bax, and displays acute desensitization of adenylyl cyclase coupling.

Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biologic effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SST4 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in fetal and adult brain and lung. SST4 enhances AMPA receptor-mediated currents in the hippocampus, and interacts with the SST2 receptor.

Somatostatin receptors (SSTRs), a family of seven transmembrane (TM) domain G-protein-coupled receptors having five distinct subtypes (termed SSTR1–5), are activated by somatostatin secreted from the nerve and endocrine cells. SSTRs are widely expressed in many tissues, frequently as multiple subtypes that coexist in the same cell. With expressions in a tissue-specific manner, SSTRs are involved in the regulation of secretion of insulin, glucagon and growth hormone as well as cell growth induced by neuronal excitation in both the central and peripheral nervous systems. The five receptors share common signaling pathways such as the inhibition of adenylyl cyclase, activation of phosphotyrosine phosphatase (PTP), and modulation of mitogen-activated protein kinase (MAPK) through G-protein-dependent mechanisms. Aberrant expression of somatostatin receptors is known to be involved in a large number of human tumors. The human medullary thyroid carcinoma cell line TT expresses all SSTR subtypes. SSTR5 induces cell cycle arrest via PTP-dependent modulation of MAPK, which is associated with the induction of the retinoblastoma tumor suppressor protein and p21. In addition, SSTR 5 displays acute desensitization of adenylyl cyclase coupling and undergoes rapid agonist-dependent endocytosis.

TIGIT (T cell immunoreceptor with Ig and ITIM domains) was recently characterized as an inhibitory receptor, which is expressed mainly on NK, Treg, CD8+ T, and CD4+ T cells. TIGIT harbors an immunoglobulin tail tyrosine (ITT)-like phosphorylation motif and an ITIM (immunoreceptor tyrosine-based inhibition motif) in its cytoplasmic tail. The poliovirus receptor (PVR or CD155) was identified as the physical ligand of TIGIT with high affinity, and PVRL2 (Nectin2 or CD112) also binds to TIGIT with a weaker binding capacity. TIGIT/PVR engagement suppresses T cell activation through IL-10 secretion mediated by dendritic cells. Furthermore, TIGIT also exerts an intrinsic inhibitory function to T cell activation.

T cell immunoglobulin mucin-3 (TIM-3) is a member of the T-cell Immunoglobulin- and Mucin-domain-containing family of type I membrane glycoproteins that regulate autoimmune and allergic disease. TIM-3 is selectively expressed on Th1 cells and interacts with galectin-9. It negatively regulates Th1 responses and affects macrophage activation. The 280 amino acid mature human TIM-3 contains a V-type Ig-like domain that shows multiple polymorphisms, followed by a mucin-like domain in the 171 amino acid extracellular region, which shares 60% amino acid identity with mouse TIM-3 ECD.

Thyrtropin-releasing hormone receptor1 (TRH1) is a member of G-protein coupled receptor family A. This protein is a receptor for Thyrtropin-releasing hormone (TRH). Human TRH1 is expressed in lymphocytes, pituitary gland and CNS. It can stimulate the releasing of prolactin (PRL), thyrotropin (TSH). TRH1 receptor knockout mice exhibit a slightly reduced growth rate, considerable decrease in serum T₃, T₄, and prolactin levels but no alteration of thyroid-stimulating hormone levels.

The Urotensin II receptor (UT2), also named UTS2R, GPR14, which is expressed in endothelium, smooth muscle, heart and pancreas. Pharmacological inhibition of urotensin II receptor interactions prevents renal insufficiency following renal artery ligation. .

The antidiuretic hormone arginine vasopressin (AVP) receptors are G protein-coupled receptors which consists of at least three types: V1A (vascular/hepatic) and V1B (anterior pituitary) receptors, which act through phosphatidylinositol hydrolysis to mobilize intracellular Ca²⁺; and V2 (kidney) receptor, which is coupled to adenylate cyclase. V1B receptors are expressed in anterior pituitary where they mediate the release of ACTH . Its peripheral actions, such as antidiuresis, contraction of vascular smooth muscle, and stimulation of hepatic glycogenolysis are well characterized.

Arginine vasopressin (AVP) is a cyclic nonapeptide that acts by binding to a family of vasopressin receptors that includes V1a, V1b, and V2 receptors. In particular, V2 receptors are expressed in kidney where vasopressin exerts its antidiuretic action. V1a and V1b couple to Gq and calcium release, whereas V2 couples to Gs. Mutations in V2 result in X-linked nephrogenic diabetes insipidus, a syndrome in which the kidney is unable to concentrate urine, leading to dehydration and hypernatremia. Conversely, elevated levels of AVP lead to hyponatremia in the syndrome of inappropriate antidiuretic hormone secretion (SIADH), congestive heart failure or cirrhosis, and V2 selective antagonists have been developed to treat these conditions.

Recombinant CHO-K1 cells stably overexpress V-domain Ig suppressor of T cell activation (VISTA) on the cell surface. The surface expression of VISTA is validated by FACS analysis. This cell line is designed for cell-based binding for screening antibodies binding with VISTA and evaluating target binding affinity.

The widespread neuropeptide vasoactive intestinal peptide (VIP) has two receptors VPAC1 and VPAC2. The vasoactive intestinal polypeptide receptor VPAC1 is G_s-coupled GPCRs expressed in the lung, prostate, peripheral blood leukocytes, liver, brain, small intestine colon, heart, spleen, placenta, kidney, thymus, and testis.

The Vasoactive intestinal polypeptide receptor 2 (VPAC2) is a Gs-coupled receptor expressed in the stroma of uterus and prostate; smooth muscles in gastrointestinal tract, seminal vesicles and skin; blood vessels; thymus. VPAC2 is an essential regulator of the circadian pacemaker of the hypothalamic suprachiasmatic nuclei.