Roger Hipkin

Learn More
Histamine exerts its numerous physiological functions through interaction with G protein-coupled receptors. Three such receptors have been defined at both the pharmacological and molecular level, while pharmacological evidence hints at the existence of further subtypes. We report here the cloning and characterization of a fourth histamine receptor subtype.(More)
The endocannabinoids anandamide and 2-arachidonyl glycerol (2-AG) bind to G protein-coupled central and peripheral cannabinoid receptors CB1 and CB2, respectively. Due to the relatively high expression of the CB2 isotype on peripheral immune cells, it has been hypothesized that this receptor mediates the immunosuppressive effects of cannabinoids.(More)
Previous studies indicated that partial agonists cause less desensitization of the beta2-adrenergic receptor (betaAR) than full agonists; however, the molecular basis for this in intact cells has not been investigated. In the present work, we have determined the rates of desensitization, internalization, and phosphorylation caused by a series of betaAR(More)
The human CXC chemokines IP-10 (10-kDa interferon-inducible protein), MIG (monokine induced by human interferon-gamma), and I-TAC (interferon-inducible T cell alpha chemoattractant) attract lymphocytes through activation of CXCR3. In the studies presented here, we examined interaction of these chemokines with human CXCR3 expressed in recombinant cells and(More)
Functional interleuin-8 (IL-8) receptors (IL-8RA and IL-8RB: CXCR1 and CXCR2, respectively) have been described in human, monkey, dog, rabbit, and guinea pig. Although three IL-8R homologues have been found in rat, only one of these, rat CXCR2, appears to be functional based on responsiveness to ligands. Similarly, CXC chemokines induce biological responses(More)
Chemokines have long been implicated in the initiation and amplification of inflammatory responses by virtue of their role in leukocyte chemotaxis. The expression of one of the receptors for these chemokines, CXCR2, on a variety of cell types and tissues suggests that these receptors may have a broad functional role under both constitutive conditions and in(More)
Human tumors frequently express somatostatin receptors. However, none of the receptor subtype proteins have been individually visualized in normal or neoplastic human tissues. Here, the distribution of the sst2A receptor was investigated using immunohistochemistry with the specific anti-peptide antibody R2-88 in 47 human tumors. All tumors selected for(More)
Inhibiting human immunodeficiency virus type 1 (HIV-1) infection by blocking the host cell coreceptors CCR5 and CXCR4 is an emerging strategy for antiretroviral therapy. Currently, several novel coreceptor inhibitors are being developed in the clinic, and early results have proven promising. In this report, we describe a novel CCR5 antagonist, vicriviroc(More)
In neutrophils, growth-related protein-alpha (CXCL1) and interleukin-8 (CXCL8), are potent chemoattractants (Cytokine 14:27-36, 2001; Biochemistry 42:2874-2886, 2003) and can stimulate myeloperoxidase release via activation of the G protein-coupled receptors CXCR1 and CXCR2. The role of CXCR1 and CXCR2 in the pathogenesis of inflammatory responses has(More)
Evidence has emerged suggesting a role for the cannabinoid CB2 receptor in immune cell motility. This provides a rationale for a novel and generalized immunoregulatory role for cannabinoid CB2 receptor-specific compounds. In support of this possibility, we will review the biology of a class of cannabinoid CB2 receptor-specific inverse agonist, the triaryl(More)