Viral Protein R (Vpr), an accessory gene of human immunodeficiency virus type 1 (HIV-1), encodes a virion-associated nuclear protein with a variety of biological functions. Forced expression of Vpr induces cell cycle abnormalities at the G2/M phase, macrophage infection, apoptosis and nuclear transportation of the pre-integration complex. Vpr is a transacting factor, and exogenously added Vpr can also induce apoptosis. It has been reported that Vpr is present in blood and cerebrospinal fluids of HIV-1 positive patients and also proposed that Vpr is linked with functional abnormality of central nervous system of the patients.
In recent years, it was reported that Vpr induces DNA double-strand breaks and activates ATM and H2AX. ATM is considered as a major physiological mediator of H2AX phosphorylation in response to DSB formation (lower panel). The focus formation of ATM phosphorylated at serine 1981 (ATM-p) and -H2AX was observed in cells with Vpr expression. In contrast, focus formation of these molecules was not observed in cells without Vpr expression (upper panel).
We commercialized Anti Vpr Monoclonal Antibody useful to the research of diagnosis technique and medical cure for HIV infection.
Focus formation of phosphorylation of ATM (ATM-p) and γ-H2AX following Vpr expression in MIT-23 cells.
The cells were stained with specific antibodies against ATM-p and γ-H2AX. The signals for ATM-p and italic γ-H2AX are depicted as red spots in the nucleus (blue).
• Vpr is detected in blood specimen of about 40% HIV-positive by using this antibody(8D1).
• Vpr in blood of HIV-positive is detected in a concentration of ng-g/mL (nM-pM).
• This antibody(8D1) has not only application to western blotting, FACS, immunoprecipitation but also the neutralizing activity.
• High-purity recombinant Vpr (rVpr) can be purified with 8D1 antibody affinity column chromatography.
lane 1 vector control
lane 2 pCMV-Vpr with SNF2h siRNA
lane 3 pCMV-Vpr with control siRNA.
Fig.1 Western blotting with 8D1 antibody using whole cell extracts of Chromatin fraction.
Chromatin fraction was prepared from HEK293T cells to which pCMV-Vpr with control and SNF2h siRNAs were transfected. (Ref. 1 Fig. 3)
lane 1 rVpr ( - )
lane 2 5 ng of standard rVpr
lane 3 2.5 ng of standard rVpr .
lane 4 1.25 ng of standard rVpr .
lane 5 Molecular marker.
lane 6 HIV-1-positive plasma #006
lane 7 HIV-1-positive plasma #011
Fig.2 Detection of Vpr in plasma of HIV-1-positive patients.
A definite signal of the 14-kDa protein was observed in patients #006 and #011 (Ref. 5 Fig. 1)
1st. Elution: Glutathione column
2nd. Elution: 8D1 affinity column
8D1: anti-Vpr monoclonal antibody Cat# NCG-M01
C217: anti-Vpr monoclonal antibody
Fig.3 LPS-free Vpr protein purification using a glutathione column and an affinity column with anti-Vpr antibody (8D1) (Ref. 4 Fig. 1)
Anti Vpr (HIV-1)
Anti Vpr (HIV-1)
1) Daiki Taneichi, et al, Identification of SNF2h, a Chromatin-Remodeling Factor, as a Novel Binding Protein of Vpr of Human Immunodeficiency Virus Type 1 J Neuroimmune Pharmacol (2011) 6:177.187 PMID: 21519849
2) Mari Shimura, et al, Epigenetic displacement of HP1 from heterochromatin by HIV-1 Vpr causes premature sister chromatid separation J Cell Biol. 2011 Sep 5; 194(5):721-35. Epub 2011 Aug 29. PMID: 21875947
3) Tram N. Q. Pham, et al, Modulation of NKG2D-Mediated Cytotoxic Functions of Natural Killer Cells by Viral Protein R from HIV-1 Primary Isolates: J.Virol. 85: 12254-12261, 2011 PMID: 21957298
4) Shigeki Hoshino, et al, HIV-1 Vpr induces TLR4/MyD88-mediated IL-6 production and reactivates viral production from latency. J. Leukoc Biol. 87:1133-1143, 2010 PMID: 20145198
5) Hoshino, S., et al, Vpr in plasma of HIV-1-positive patients is correlated with the HIV-1 RNA titers. AIDS Res. Hum. Retrovir. 23, 391-397, 2007. PMID: 17411372
6) Nakai-Murakami C, et al, HIV-1 Vpr induces ATM-dependent cellular signal with enhanced homologous recombination. Oncogene. 2007 Jan 25;26(4):477-86. PMID: 16983346
To be used for research only. DO NOT use for human gene therapy or clinical diagnosis.