Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Aug 15;174(4):437-45.
doi: 10.1164/rccm.200601-005OC. Epub 2006 May 25.

HIV-1 Nef is associated with complex pulmonary vascular lesions in SHIV-nef-infected macaques

John C Marecki  1 , Carlyne D Cool, Jane E Parr, Virginia E Beckey, Paul A Luciw, Alice F Tarantal, Angela Carville, Richard P Shannon, Adela Cota-Gomez, Rubin M Tuder, Norbert F Voelkel, Sonia C Flores
Affiliations

HIV-1 Nef is associated with complex pulmonary vascular lesions in SHIV-nef-infected macaques

John C Marecki et al. Am J Respir Crit Care Med. .

Abstract

Rationale: HIV-infected patients with pulmonary arterial hypertension have histologic manifestations that are indistinguishable from those found in patients with idiopathic pulmonary arterial hypertension. In addition, the role of pleiotropic viral proteins in the development of plexiform lesions in HIV-related pulmonary hypertension (HRPH) has not been explored. Simian immunodeficiency virus (SIV) infection of macaques has been found to closely recapitulate many of the characteristic features of HIV infection, and thus hallmarks of pulmonary arterial hypertension should also be found in this nonhuman primate model of HIV.

Objectives: To determine whether pulmonary arterial lesions were present in archived SIV-infected macaque lung tissues from Johns Hopkins University and two National Primate Research Centers.

Methods: Archived macaque and human lung sections were examined via immunohistochemistry for evidence of complex vascular lesions.

Results: Complex plexiform-like lesions characterized by lumenal obliteration, intimal disruption, medial hypertrophy, thrombosis, and recanalized lumena were found exclusively in animals infected with SHIV-nef (a chimeric viral construct containing the HIV nef gene in an SIV backbone), but not in animals infected with SIV. The mass of cells in the lesions were factor VIII positive, and contained cells positive for muscle-specific and smooth muscle actins. Lung mononuclear cells were positive for HIV Nef, suggesting viral replication. Endothelial cells in both the SHIV-nef macaques and patients with HRPH, but not in patients with idiopathic pulmonary arterial hypertension, were also Nef positive.

Conclusions: The discovery of complex vascular lesions in SHIV-nef- but not SIV-infected animals, and the presence of Nef in the vascular cells of patients with HRPH, suggest that Nef plays a key role in the development of severe pulmonary arterial disease.

PubMed Disclaimer

Figures

<b>Figure 1.</b>
Figure 1.
Pulmonary vasculature and plexiform lesions in macaques infected with simian immunodeficiency virus (SIV) or SHIV-nef (a chimeric viral construct containing the HIV nef gene in an SIV backbone). Paraffin-embedded sections from the lungs of macaques infected with SIVmac251-NENPRC1 (A), SHIV-nef1486D95-NENPRC7 (B), SHIV-nef1486D95-NENPRC8 (C), SIVmac239-CNPRC1 (D), SHIV-nefSF33A-CNPRC3 (E), or SHIV-nefSF33A-CNPRC4 (F) were stained with hematoxylin and eosin (H&E) and examined for vascular pathologies by two independent pathologists. Arrows indicate vessels with lymphocytic infiltration (SIV) and plexiform-like lesions (SHIV-nef). Scale bars: 100 μm.
<b>Figure 2.</b>
Figure 2.
Characterization of vascular cells in the lesions of SHIV-nef macaques from the New England National Primate Research Center (NENPRC) and the California National Primate Research Center (CNPRC) cohorts. Paraffin-embedded serial sections from animals NENPRC7 (A–C) and NENPRC8 (D–F), and from animals CNPRC3 (G–I) and CNPRC4 (J–L), were stained with H&E (A, D, G, and J), factor VIII (B, E, H, and K), and mouse monoclonal anti–muscle specific actin (MSA; C, F, I, and L) for visualization of endothelial cells and smooth muscle cells in the plexiform lesions. Scale bars: 50 μm.
<b>Figure 3.</b>
Figure 3.
Identification of endothelial and smooth muscle cell markers in a lesion from an SHIV-nef animal (NENPRC7). Endothelial cells stained with factor VIII (A and B) and smooth muscle cells stained with α-smooth muscle actin (α-SMA; C and D) in lesions from the SHIV-nef animal NENPRC7. Arrows indicate regions of mixed endothelial and smooth muscle cell staining in the lesion. (B) and (D) are magnifications of the lesion in (A) and (C), respectively. Scale bars: (A and C) 50 μm; (B and D) 100 μm.
<b>Figure 4.</b>
Figure 4.
Colocalization of HIV-1 Nef in pulmonary arterial endothelial cells in human patients with HIV-related pulmonary hypertension (HRPH), but not in normal humans or in patients with idiopathic pulmonary arterial hypertension (IPAH). Paraffin-embedded lung sections from normal human lung (A–D), human IPAH lung with plexiform lesions (E–H), and human HRPH lung (I–L) were stained with a monoclonal antibody to HIV-1 Nef and counterstained with methyl green (A, E, and I). Separate sections from the same patients were dual-stained with a rabbit polyclonal antibody to factor VIII and detected with an Alexa Fluor 488–conjugated goat anti-rabbit secondary antibody (B, F, and J) and a mouse monoclonal antibody to HIV-1 Nef and detected with a goat anti-mouse antibody, using Vector red (C, G, and K). The factor VIII and Nef images were digitally merged (D, H, and L) to demonstrate colocalization of Nef in endothelial cells. Human lungs from normal subjects and patients with IPAH lacked staining in either infiltrating mononuclear cells, plexiform lesions, or the unaffected vasculature. The lung from a patient with HRPH showed distinct positive staining in the occluding cells of a plexiform lesion (I, arrows) as well as localization to the endothelial cell layer (K and L, arrows) in an uninvolved vessel from the same section. N = normal patient; I = patient with IPAH; H = patient with HRPH; L = lumen.
<b>Figure 5.</b>
Figure 5.
Colocalization of HIV-1 Nef in pulmonary arterial endothelial cells in SHIV-nef–infected macaques, but not in SIV-infected macaques. Paraffin-embedded lung sections from SIV-infected macaque lung (A–D), SHIV-nefSF33A-CNPRC3 lung (E–H), and SHIV-nefSF33A-CNPRC4 lung (I–L) were stained with a monoclonal antibody to HIV-1 Nef and counterstained with methyl green (A, E, and I). Separate sections from the same animals were dual-stained with a rabbit polyclonal antibody to factor VIII and detected with an Alexa Fluor 488–conjugated goat anti-rabbit secondary antibody (B, F, and J) and a mouse monoclonal antibody to HIV-1 Nef and detected with a goat anti-mouse antibody, using Vector red (C, G, and K). The factor VIII and Nef images were digitally merged (D, H, and L) to demonstrate colocalization in vascular cells. SIV-infected lungs showed no evidence of Nef staining. The staining pattern in the SHIV-nef macaque lungs mimicks the findings in human tissues, with staining in the endothelial cell layer (E, G, and H, arrows) as well as in perivascular sites with massive lymphocytic infiltration (I, K, and L, arrows). S = SIV; SH = SHIV-nef.
<b>Figure 6.</b>
Figure 6.
Hypothetical relationship between HIV-1 Nef and the development of severe angioproliferative pulmonary hypertension. The accessory HIV-1 protein Nef (solid triangles) is expressed early during infection in HIV-infected resident alveolar macrophages and circulating lymphocytes, providing proximate sources for viral proteins for surrounding cells and the circulation. The uptake of Nef into vascular endothelial cells (ECs), in conjunction with immune insufficiency, leads to endothelial cell dysfunction and apoptosis. The engulfment of apoptotic cells by surrounding endothelial cells leads to an apoptosis-resistant population with increased secretion of cytokines and growth factors (GFs). The uncontrolled endothelial cell proliferation leads to complex vascular remodeling, plexiform lesions, and HRPH.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Kim KK, Factor SM. Membranoproliferative glomerulonephritis and plexogenic pulmonary arteriopathy in a homosexual man with acquired immunodeficiency syndrome. Hum Pathol 1987;18:1293–1296. - PubMed
    1. Speich R, Jenni R, Opravil M, Pfab M, Russi EW. Primary pulmonary hypertension in HIV infection. Chest 1991;100:1268–1271. - PubMed
    1. Mette SA, Palevsky HI, Pietra GG, Williams TM, Bruder E, Prestipino AJ, Patrick AM, Wirth JA. Primary pulmonary hypertension in association with human immunodeficiency virus infection: a possible viral etiology for some forms of hypertensive pulmonary arteriopathy. Am Rev Respir Dis 1992;145:1196–1200. - PubMed
    1. Pellicelli AM, Palmieri F, D'Ambrosio C, Rianda A, Boumis E, Girardi E, Antonucci G, D'Amato C, Borgia MC. Role of human immunodeficiency virus in primary pulmonary hypertension: case reports. Angiology 1998;49:1005–1011. - PubMed
    1. Sitbon O, Gressin V, Speich R, Macdonald PS, Opravil M, Cooper DA, Fourme T, Humbert M, Delfraissy JF, Simonneau G. Bosentan for the treatment of human immunodeficiency virus–associated pulmonary arterial hypertension. Am J Respir Crit Care Med 2004;170:1212–1217. - PubMed

Publication types

MeSH terms

Substances