Norma P. Gerard

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We examined the ability of chemokine receptors and related G protein-coupled receptors to facilitate infection by primary, clinical HIV-1 isolates. CCR5, when expressed along with CD4, the HIV-1 receptor, allowed cell lines resistant to most primary HIV-1 isolates to be infected. CCR3 facilitated infection by a more restricted subset of primary viruses, and(More)
The Gram-positive bacterium Streptococcus pneumoniae is a major cause of pneumonia, sepsis and meningitis. Although the invasive disease is severe, some 40% of individuals harbour the pneumococcus in the nasopharynx asymptomatically. Here we investigate the molecular elements of the encounter between host and pathogen that distinguish these different(More)
Amyloid beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We examined the role of neprilysin, a candidate Abeta-degrading peptidase, in the metabolism using neprilysin gene-disrupted mice. Neprilysin deficiency resulted in defects both in the degradation of exogenously administered Abeta and(More)
Chemokine receptors and related seven-transmembrane-segment (7TMS) receptors serve as coreceptors for entry of human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIV) into target cells. Each of these otherwise diverse coreceptors contains an N-terminal region that is acidic and tyrosine rich. Here, we show that the chemokine receptor CCR5, a(More)
Ubiquitously expressed seven-transmembrane receptors (7TMRs) classically signal through heterotrimeric G proteins and are commonly referred to as G protein-coupled receptors. It is now recognized that 7TMRs also signal through beta-arrestins, which act as versatile adapters controlling receptor signaling, desensitization, and trafficking. Most endogenous(More)
Using a combined pharmacological and gene-deletion approach, we have delineated a novel mechanism of neurokinin-1 (NK-1) receptor-dependent hyperalgesia induced by proteinase-activated receptor-2 (PAR2), a G-protein-coupled receptor expressed on nociceptive primary afferent neurons. Injections into the paw of sub-inflammatory doses of PAR2 agonists in rats(More)
The function of the C5a receptors, C5ar (encoded by C5ar) and C5l2 (encoded by Gpr77), especially of C5l2, which was originally termed a 'default receptor', remains a controversial topic. Here we investigated the role of each receptor in the setting of cecal ligation and puncture-induced sepsis by using antibody-induced blockade of C5a receptors and(More)
Among the first cells to invade a site of infection, polymorphonuclear neutrophils (PMN) play an important role in the control of numerous infections. While PMN are considered critical for control of acute infections, their role in chronic infections remains less well understood. Here we report that PMN are essential for accurate early granuloma formation(More)
For efficient entry into target cells, primary macrophage-tropic and laboratory-adapted human immunodeficiency viruses type 1 (HIV-1) require particular chemokine receptors, CCR-5 and CXCR-4, respectively, as well as the primary receptor CD4 (refs 1-6). Here we show that a complex of gp120, the exterior envelope glycoprotein, of macrophage-tropic primary(More)
The complement anaphylatoxin C5a is a proinflammatory component of host defense that functions through two identified receptors, C5a receptor (C5aR) and C5L2. C5aR is a classical G protein-coupled receptor, whereas C5L2 is structurally homologous but deficient in G protein coupling. In human neutrophils, we show C5L2 is predominantly intracellular, whereas(More)