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P Di Marzio

Bio: P Di Marzio is an academic researcher from Aaron Diamond AIDS Research Center. The author has contributed to research in topics: Viral replication & Virus. The author has an hindex of 4, co-authored 4 publications receiving 4938 citations.

Papers
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Journal ArticleDOI
20 Jun 1996-Nature
TL;DR: The principal cofactor for entry mediated by the envelope glycoproteins of primary macrophage-tropic strains of HIV-1 is CC-CKR-5, a receptor for the β-chemokines RANTES, Mip-1α and MIP-1β.
Abstract: Entry of HIV-1 into target cells requires cell-surface CD4 and additional host cell cofactors. A cofactor required for infection with virus adapted for growth in transformed T-cell lines was recently identified and named fusin. However, fusin does not promote entry of macrophage-tropic viruses, which are believed to be the key pathogenic strains in vivo. The principal cofactor for entry mediated by the envelope glycoproteins of primary macrophage-tropic strains of HIV-1 is CC-CKR-5, a receptor for the β-chemokines RANTES, MIP-1α and MIP-1β.

3,802 citations

Journal ArticleDOI
TL;DR: It is shown here that Vpr arrests the cell cycle in G2 by preventing the activation of the p34cdc2/cyclin B complex that is required for entry into M phase, and in vivo, Vpr might, by preventing p34CDc2 activation, delay or prevent apoptosis of infected cells.
Abstract: The Vpr accessory gene product of human immunodeficiency virus types 1 and 2 and simian immunodeficiency virus is believed to play a role in permitting entry of the viral core into the nucleus of nondividing cells. A second role for Vpr was recently suggested by Rogel et al. (M. E. Rogel, L. I. Wu, and M. Emerman, J. Virol. 69:882-888, 1995), who showed that Vpr prevents the establishment in vitro of chronically infected HIV producer cell lines, apparently by causing infected cells to arrest in the G2/M phase of the cell cycle. In cycling cells, progression from G2 to M phase is driven by activation of the p34cdc2/cyclin B complex, an event caused, in part, by dephosphorylation of two regulatory amino acids of p34cdc2 (Thr-14 and Tyr-15). We show here that Vpr arrests the cell cycle in G2 by preventing the activation of the p34cdc2/cyclin B complex. Vpr expression in cells caused p34cdc2 to remain in the phosphorylated, inactive state, p34cdc2/cyclin B complexes immunoprecipitated from cells expressing Vpr were almost completely inactive in a histone H1 kinase assay. Coexpression of a constitutively active mutant p34cdc2 molecule with Vpr relieved the G2 arrest. These findings strongly suggest that Vpr arrests cells in G2 by preventing the activation of the p34cdc2/cyclin B complex that is required for entry into M phase. In vivo, Vpr might, by preventing p34cdc2 activation, delay or prevent apoptosis of infected cells. This would increase the amount of virus each infected cell produced.

916 citations

Journal ArticleDOI
TL;DR: It is speculated that human immunodeficiency virus type 1 Vpr has two sites for interaction with cellular factors: one in the alpha-helical region that specifies nuclear localization andOne in the carboxy-terminal domain that is required for Cdc2 inhibition.
Abstract: Human immunodeficiency virus type 1 Vpr is a virion-associated, regulatory protein that is required for efficient viral replication in monocytes/macrophages. The protein is believed to act in conjunction with the Gag matrix protein to allow import of the viral preintegration complex in nondividing cells. In cells, Vpr localizes to the nucleus. Recently, we showed that Vpr prevents the activation of p34cdc2-cyclin B. This results in arrest of Vpr-expressing cells in the G2/M phase of the cell cycle. Here, we use a panel of expression vectors encoding Vpr molecules mutated in the amino-terminal alpha-helical region, the central hydrophobic region, or the carboxy-terminal basic region to define the functional domains of the protein. The results showed cell cycle arrest was largely controlled by the carboxy-terminal basic domain of the protein. In contrast, the amino-terminal alpha-helical region of Vpr was required for nuclear localization and packaging into virions. The carboxy terminus appeared to be unnecessary for nuclear localization. In the alpha-helical region, mutation of Ala-30 to Pro resulted in a protein that localized to the cytoplasm. Surprisingly, fusion of Vpr to luciferase resulted in a molecule that failed to localize to the nucleus. In addition, we show that simian immunodeficiency virus Vpr, but not Vpx, induces G2 arrest. We speculate that Vpr has two sites for interaction with cellular factors: one in the alpha-helical region that specifies nuclear localization and one in the carboxy-terminal domain that is required for Cdc2 inhibition.

273 citations

Journal ArticleDOI
01 Oct 2000-Cytokine
TL;DR: It is reported here that treating monocyte-derived macrophages (MDM) with a trimeric soluble form of CD40L (CD40LT) induced them to secrete high levels of the beta-chemokines RANTES, Mip-1alpha and MIP-1beta that are ligands for CCR5 and able to inhibit HIV-1 entry.

23 citations


Cited by
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Journal ArticleDOI
20 Jun 1996-Nature
TL;DR: The principal cofactor for entry mediated by the envelope glycoproteins of primary macrophage-tropic strains of HIV-1 is CC-CKR-5, a receptor for the β-chemokines RANTES, Mip-1α and MIP-1β.
Abstract: Entry of HIV-1 into target cells requires cell-surface CD4 and additional host cell cofactors. A cofactor required for infection with virus adapted for growth in transformed T-cell lines was recently identified and named fusin. However, fusin does not promote entry of macrophage-tropic viruses, which are believed to be the key pathogenic strains in vivo. The principal cofactor for entry mediated by the envelope glycoproteins of primary macrophage-tropic strains of HIV-1 is CC-CKR-5, a receptor for the β-chemokines RANTES, MIP-1α and MIP-1β.

3,802 citations

Journal ArticleDOI
TL;DR: This review introduces the burgeoning family of cytokines, with special emphasis on their role in the pathophysiology of disease and their potential as targets for therapy.
Abstract: The attraction of leukocytes to tissues is essential for inflammation and the host response to infection. The process is controlled by chemokines, which are chemotactic cytokines. This review introduces the burgeoning family of cytokines, with special emphasis on their role in the pathophysiology of disease and their potential as targets for therapy. Structure and Function of Chemokines Over 40 chemokines have been identified to date, most of them in the past few years. The relations among chemokines were not initially appreciated, which led to an idiosyncratic nomenclature consisting of many acronyms. When initially identified, these proteins had no known biologic . . .

3,653 citations

Journal ArticleDOI
09 Aug 1996-Cell
TL;DR: A CKR-5 allele present in the human population appears to protect homozygous individuals from sexual transmission of HIV-1 and is suggested to provide a means of preventing or slowing disease progression.

3,110 citations

Journal ArticleDOI
22 Aug 1996-Nature
TL;DR: It is shown that a mutant allele of CCR-5 is present at a high frequency in caucasian populations, but is absent in black populations from Western and Central Africa and Japanese populations, and a 32-base-pair deletion within the coding region results in a frame shift, and generates a non-functional receptor that does not support membrane fusion or infection by macrophage- and dual-tropic HIV-1 strains.
Abstract: HIV-1 and related viruses require co-receptors, in addition to CD4, to infect target cells. The chemokine receptor CCR-5 (ref.1) was recently demonstrated to be a co-receptor for macrophage-tropic (M-tropic) HIV-1 strains, and the orphan receptor LESTR (also called fusin) allows infection by strains adapted for growth in transformed T-cell lines (T-tropic strains). Here we show that a mutant allele of CCR-5 is present at a high frequency in caucasian populations (allele frequency, 0.092), but is absent in black populations from Western and Central Africa and Japanese populations. A 32-base-pair deletion within the coding region results in a frame shift, and generates a non-functional receptor that does not support membrane fusion or infection by macrophage- and dual-tropic HIV-1 strains. In a cohort of HIV-1 infected caucasian subjects, no individual homozygous for the mutation was found, and the frequency of heterozygotes was 35% lower than in the general population. White blood cells from an individual homozygous for the null allele were found to be highly resistant to infection by M-tropic HIV-1 viruses, confirming that CCR-5 is the major co-receptor for primary HIV-1 strains. The lower frequency of heterozygotes in seropositive patients may indicate partial resistance.

2,668 citations

Journal ArticleDOI
27 Sep 1996-Science
TL;DR: The CKR5Δ32 deletion may act as a recessive restriction gene against HIV-1 infection and may exert a dominant phenotype of delaying progression to AIDS among infected individuals.
Abstract: The chemokine receptor 5 (CKR5) protein serves as a secondary receptor on CD4 + T lymphocytes for certain strains of human immunodeficiency virus-type 1 (HIV-1). The CKR5 structural gene was mapped to human chromosome 3p21, and a 32-base pair deletion allele ( CKR5Δ32 ) was identified that is present at a frequency of ∼0.10 in the Caucasian population of the United States. An examination of 1955 patients included among six well-characterized acquired immunodeficiency syndrome (AIDS) cohort studies revealed that 17 deletion homozygotes occurred exclusively among 612 exposed HIV-1 antibody-negative individuals (2.8 percent) and not at all in 1343 HIV-1-infected individuals. The frequency of CKR5 deletion heterozygotes was significantly elevated in groups of individuals that had survived HIV-1 infection for more than 10 years, and, in some risk groups, twice as frequent as their occurrence in rapid progressors to AIDS. Survival analysis clearly shows that disease progression is slower in CKR5 deletion heterozygotes than in individuals homozygous for the normal CKR5 gene. The CKR5Δ32 deletion may act as a recessive restriction gene against HIV-1 infection and may exert a dominant phenotype of delaying progression to AIDS among infected individuals.

2,586 citations