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Mashikian MV, Ryan TC, Seman A, Brazer W, Center DM, Cruikshank WW. Reciprocal Desensitization of CCR5 and CD4 Is Mediated by IL-16 and Macrophage-Inflammatory Protein-1β, Respectively. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.6.3123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The ability of HIV-1 gp120 to inhibit chemokine signaling prompted us to determine whether signaling through CD4 by a natural ligand, IL-16, could alter cellular responsiveness to chemokine stimulation. These studies demonstrate that IL-16/CD4 signaling in T lymphocytes results in a selective loss of macrophage-inflammatory protein (MIP)-1β/CCR5-induced chemotaxis. There was no effect on monocyte chemoattractant protein-2/CCR1, -2, or -3-induced chemotaxis. Desensitization of CCR5 by IL-16 required at least 10 min of pretreatment; no modulation of CCR5 expression was observed, nor was MIP-1β binding to CCR5 altered. Using murine T cell hybridomas transfected to express native or mutated forms of CD4, it was determined that IL-16/CD4 induces a p56lck-dependent signal that results in desensitization of CCR5. The desensitization process is reciprocal and again selective, as prior CCR5 stimulation, but not CCR1, -2, or -3 stimulation, completely inhibits IL-16/CD4-induced T cell migration. Of interest, while p56lck enzymatic activity is not required for IL-16-induced migration, it was required for desensitization of CCR5. These studies indicate the existence of reciprocal receptor cross-desensitization between CD4 and CCR5 induced by two proinflammatory cytokines and suggest a selective relationship between the two receptors.
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Affiliation(s)
| | - T. C. Ryan
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118
| | - A. Seman
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118
| | - W. Brazer
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118
| | - D. M. Center
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118
| | - W. W. Cruikshank
- Pulmonary Center, Boston University School of Medicine, Boston, MA 02118
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Koedel U, Kohleisen B, Sporer B, Lahrtz F, Ovod V, Fontana A, Erfle V, Pfister HW. HIV Type 1 Nef Protein Is a Viral Factor for Leukocyte Recruitment into the Central Nervous System. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.3.1237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Recombinant HIV-1 Nef protein, but not Tat, gp120, and gp160, provoked leukocyte recruitment into the CNS in a rat model. The strong reduction of bioactivity by heat treatment of Nef, and the blocking effect of the mAb 2H12, which recognizes the carboxy-terminal amino acid (aa) residues 171–190 (but not of mAb 3E6, an anti-Nef Ab of the same isotype, which maps the aa sequence 168–175, as well as a mixture of mAbs to CD4) provided evidence for the specificity of the observed Nef effects. Using a modified Boyden chamber technique, Nef exhibited chemotactic activity on mononuclear cells in vitro. Coadministration of the anti-Nef mAb 2H12, as well as treatment of Nef by heat inhibited Nef-induced chemotaxis. Besides soluble Nef, chemotaxis was also induced by a Nef-expressing human astrocytoma cell line, but not by control cells. These data suggest a direct chemotactic activity of soluble Nef. The detection of elevated levels of IL-6, TNF-α, and IFN-γ in rat cerebrospinal fluid 6 h after intracisternal Nef injection hint at the additional involvement of indirect mechanisms in Nef-induced leukocyte migration into rat CNS. These data propose a mechanism by which HIV-1 Nef protein may be essential for AIDS neuropathogenesis, as a mediator of the recruitment of leukocytes that may serve as vehicles of the virus and perpetrators for disease through their production of neurotoxins.
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Affiliation(s)
- Uwe Koedel
- *Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Birgit Kohleisen
- †Institute of Molecular Virology, GSF-Research Center for Environment and Health Neuherberg, Neuherberg; Germany,
| | - Bernd Sporer
- *Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Fritz Lahrtz
- ‡Institute of Biomedical Sciences, University of Tampere, Tampere, Finland; and
| | - Vladimir Ovod
- ‡Institute of Biomedical Sciences, University of Tampere, Tampere, Finland; and
| | - Adriano Fontana
- §Institute of Clinical Immunology, University Hospital Zürich, Zürich, Switzerland
| | - Volker Erfle
- †Institute of Molecular Virology, GSF-Research Center for Environment and Health Neuherberg, Neuherberg; Germany,
| | - Hans-Walter Pfister
- *Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University of Munich, Munich, Germany
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Su SB, Gao JL, Gong WH, Dunlop NM, Murphy PM, Oppenheim JJ, Wang JM. T21/DP107, A Synthetic Leucine Zipper-Like Domain of the HIV-1 Envelope gp41, Attracts and Activates Human Phagocytes by Using G-Protein-Coupled Formyl Peptide Receptors. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.10.5924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
A leucine zipper-like domain, T21/DP107, located in the amino terminus of the ectodomain of gp41, is crucial to the formation of fusogenic configuration of the HIV-1 envelope protein gp41. We report that the synthetic T21/DP107 segment is a potent stimulant of migration and calcium mobilization in human monocytes and neutrophils. The activity of T21/DP107 on phagocytes was pertussis toxin-sensitive, suggesting this peptide uses Gi-coupled seven-transmembrane receptor(s). Since the bacterial chemotactic peptide fMLP partially desensitized the calcium-mobilizing activity of T21/DP107 in phagocytes, we postulated that T21/DP107 might preferentially use a lower affinity fMLP receptor. By using cells transfected to express cloned prototype chemotactic N-formyl peptide receptor (FPR) or its variant, FPR-like 1 (FPRL1), we demonstrate that T21/DP107 activates both receptors but has a much higher efficacy for FPRL1. In addition, T21/DP107 at nM concentrations induced migration of FPRL1-transfected human embryonic kidney 293 cells. In contrast, fMLP did not induce significant chemotaxis of the same cells at a concentration as high as 50 μM. Although a lipid metabolite, lipoxin A4, was a high-affinity ligand for FPRL1, it was not reported to induce Ca2+ mobilization or chemotaxis in FPRL1-transfected cells. Therefore, T21/DP107 is a first chemotactic peptide agonist identified thus far for FPRL1. Our results suggest that this peptide domain of the HIV-1 gp41 may have the potential to activate host innate immune response by interacting with FPR and FPRL1 on phagocytes.
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Affiliation(s)
- Shao Bo Su
- *Laboratory of Molecular Immunoregulation, Division of Basic Sciences
| | - Ji-liang Gao
- ‡Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Wang-hua Gong
- †Intramural Research Support Program, Science Applications International Corporation-Frederick, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, MD 21702; and
| | - Nancy M. Dunlop
- *Laboratory of Molecular Immunoregulation, Division of Basic Sciences
| | - Philip M. Murphy
- ‡Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | | | - Ji Ming Wang
- *Laboratory of Molecular Immunoregulation, Division of Basic Sciences
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