scholarly journals Cell-to-Cell Spreading of HIV-1 in Myeloid Target Cells Escapes SAMHD1 Restriction

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Maorong Xie ◽  
Héloïse Leroy ◽  
Rémi Mascarau ◽  
Marie Woottum ◽  
Maeva Dupont ◽  
...  

ABSTRACT Dendritic cells (DCs) and macrophages as well as osteoclasts (OCs) are emerging as target cells of HIV-1 involved in virus transmission, dissemination, and establishment of persistent tissue virus reservoirs. While these myeloid cells are poorly infected by cell-free viruses because of the high expression levels of cellular restriction factors such as SAMHD1, we show here that HIV-1 uses a specific and common cell-to-cell fusion mechanism for virus transfer and dissemination from infected T lymphocytes to the target cells of the myeloid lineage, including immature DCs (iDCs), OCs, and macrophages, but not monocytes and mature DCs. The establishment of contacts with infected T cells leads to heterotypic cell fusion for the fast and massive transfer of viral material into OC and iDC targets, which subsequently triggers homotypic fusion with noninfected neighboring OCs and iDCs for virus dissemination. These two cell-to-cell fusion processes are not restricted by SAMHD1 and allow very efficient spreading of virus in myeloid cells, resulting in the formation of highly virus-productive multinucleated giant cells. These results reveal the cellular mechanism for SAMHD1-independent cell-to-cell spreading of HIV-1 in myeloid cell targets through the formation of the infected multinucleated giant cells observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients. IMPORTANCE We demonstrate that HIV-1 uses a common two-step cell-to-cell fusion mechanism for massive virus transfer from infected T lymphocytes and dissemination to myeloid target cells, including dendritic cells and macrophages as well as osteoclasts. This cell-to-cell infection process bypasses the restriction imposed by the SAMHD1 host cell restriction factor for HIV-1 replication, leading to the formation of highly virus-productive multinucleated giant cells as observed in vivo in lymphoid and nonlymphoid tissues of HIV-1-infected patients. Since myeloid cells are emerging as important target cells of HIV-1, these results contribute to a better understanding of the role of these myeloid cells in pathogenesis, including cell-associated virus sexual transmission, cell-to-cell virus spreading, and establishment of long-lived viral tissue reservoirs.

Author(s):  
Sandra M. Gonzalez ◽  
Wbeimar Aguilar-Jimenez ◽  
Natalia Alvarez ◽  
Maria T. Rugeles

Abstract Background Dendritic cells (DCs) play a crucial role during HIV-1 transmission due to their ability to transfer virions to susceptible CD4+ T cells, particularly in the lymph nodes during antigen presentation which favors the establishment of systemic infection. As mature dendritic cells (mDCs) exhibit a greater ability to transfer virions, compared to immature DCs (iDCs), maintenance of an iDC phenotype could decrease viral transmission. The immunomodulatory vitamin D (VitD) has been shown to reduce activation and maturation of DCs; hence, we hypothesized that it would reduce viral transference by DCs. Materials and methods We evaluated the effect of in vitro treatment with a precursor of VitD, cholecalciferol, on the activation/maturation phenotype of differentiated monocyte-derived DCs and their ability to transfer HIV-1 to autologous CD4+ T cells. Results Our findings show that although cholecalciferol decreases the activation of iDCs, it did not impact the maturation phenotype after LPS treatment nor iDCs’ ability to transfer viral particles to target cells. Conclusion These findings suggest that despite cholecalciferol potentially modulates the phenotype of mucosal iDCs in vivo, such modulation might not impact the ability of these cells to transfer HIV-1 to target CD4+ T cells.


2008 ◽  
Vol 82 (16) ◽  
pp. 7886-7896 ◽  
Author(s):  
Thijs van Montfort ◽  
Adri A. M. Thomas ◽  
Georgios Pollakis ◽  
William A. Paxton

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) preferentially utilizes the CCR5 coreceptor for target cell entry in the acute phase of infection, while later in disease progression the virus switches to the CXCR4 coreceptor in approximately 50% of patients. In response to HIV-1 the adaptive immune response is triggered, and antibody (Ab) production is elicited to block HIV-1 entry. We recently determined that dendritic cells (DCs) can efficiently capture Ab-neutralized HIV-1, restore infectivity, and transmit infectious virus to target cells. Here, we tested the effect of Abs on trans transmission of CCR5 or CXCR4 HIV-1 variants. We observed that transmission of HIV-1 by immature as well as mature DCs was significantly higher for CXCR4- than CCR5-tropic viral strains. Additionally, neutralizing Abs directed against either the gp41 or gp120 region of the envelope such as 2F5, 4E10, and V3-directed Abs inhibited transmission of CCR5-tropic HIV-1, whereas Ab-treated CXCR4-tropic virus demonstrated unaltered or increased transmission. To further study the effects of coreceptor usage we tested molecularly cloned HIV-1 variants with modifications in the envelope that were based on longitudinal gp120 V1 and V3 variable loop sequences from a patient progressing to AIDS. We observed that DCs preferentially facilitated infection of CD4+ T lymphocytes of viral strains with an envelope phenotype found late in disease. Taken together, our results illustrate that DCs transmit CXCR4-tropic HIV-1 much more efficiently than CCR5 strains; we hypothesize that this discrimination could contribute to the in vivo coreceptor switch after seroconversion and could be responsible for the increase in viral load.


2017 ◽  
Vol 91 (24) ◽  
Author(s):  
Lucie Bracq ◽  
Maorong Xie ◽  
Marie Lambelé ◽  
Lan-Trang Vu ◽  
Julie Matz ◽  
...  

ABSTRACT HIV-1-infected macrophages participate in virus dissemination and establishment of virus reservoirs in host tissues, but the mechanisms for virus cell-to-cell transfer to macrophages remain unknown. Here, we reveal the mechanisms for cell-to-cell transfer from infected T cells to macrophages and virus spreading between macrophages. We show that contacts between infected T lymphocytes and macrophages lead to cell fusion for the fast and massive transfer of CCR5-tropic viruses to macrophages. Through the merge of viral material between T cells and macrophages, these newly formed lymphocyte-macrophage fused cells acquire the ability to fuse with neighboring noninfected macrophages. Together, these two-step envelope-dependent cell fusion processes lead to the formation of highly virus-productive multinucleated giant cells reminiscent of the infected multinucleated giant macrophages detected in HIV-1-infected patients and simian immunodeficiency virus-infected macaques. These mechanisms represent an original mode of virus transmission for viral spreading and a new model for the formation of macrophage virus reservoirs during infection. IMPORTANCE We reveal a very efficient mechanism involved in cell-to-cell transfer from infected T cells to macrophages and subsequent virus spreading between macrophages by a two-step cell fusion process. Infected T cells first establish contacts and fuse with macrophage targets. The newly formed lymphocyte-macrophage fused cells then acquire the ability to fuse with surrounding uninfected macrophages, leading to the formation of infected multinucleated giant cells that can survive for a long time, as evidenced in vivo in lymphoid organs and the central nervous system. This route of infection may be a major determinant for virus dissemination and the formation of macrophage virus reservoirs in host tissues during HIV-1 infection.


2006 ◽  
Vol 14 (4) ◽  
pp. 203-206 ◽  
Author(s):  
Michael S. Wertheim ◽  
William D. Mathers ◽  
Lyndell Lim ◽  
Angela S. Watkins ◽  
Friederike Mackensen ◽  
...  

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Baohui Xu ◽  
Haojun Xuan ◽  
Naoki Fujimura ◽  
Sara A Michie ◽  
Ronald L Dalman

Introduction: Abdominal aortic aneurysms (AAA) manifest histologic features consistent with other chronic inflammatory diseases. Infiltrating mural myeloid cells (e.g. macrophages) are already recognized as important contributors to aneurysm pathogenesis, however, the role of plasmacytoid dendritic cells (pDC), major type 1 interferon-producing myeloid cells involving in autoimmune diseases and atherosclerosis, has not been previously investigated in this context. Methods and Results: AAAs were created in 12 week old male C57BL/6J mice by transient intra-aortic infusion of porcine pancreatic elastase (PPE). AAA development and progression were assessed via serial ultrasound determination of aortic diameter in vivo , and histology at sacrifice. The fraction of circulating leukocytes identified as pDCs was significantly increased immediately following PPE infusion (aneurysm initiation). Treatment with mPDCA-1 mAb (400 μg i.p. q.o.d.), beginning one day prior to PPE infusion, depleted more than 90% of bone marrow, spleen and peripheral blood pDCs (data not shown) and suppressed subsequent aneurysm development and progression compared to that noted in PPE-infused mice treated with control mAb. mPDCA-1 treatment promoted aortic medial elastin and smooth muscle preservation, while limiting mural macrophage accumulation and neocapillary formation. Conclusion: These findings suggest a role for plasmacytoid dendritic cells in promoting the initiation and progression of experimental abdominal aortic aneurysms.


2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Jennifer A. Juno ◽  
Kathleen M. Wragg ◽  
Anne B. Kristensen ◽  
Wen Shi Lee ◽  
Kevin J. Selva ◽  
...  

ABSTRACT Sexual HIV-1 transmission occurs primarily in the presence of semen. Although data from macaque studies suggest that CCR5+ CD4+ T cells are initial targets for HIV-1 infection, the impact of semen on T cell CCR5 expression and ligand production remains inconclusive. To determine if semen modulates the lymphocyte CCR5 receptor/ligand axis, primary human T cell CCR5 expression and natural killer (NK) cell anti-HIV-1 antibody-dependent beta chemokine production was assessed following seminal plasma (SP) exposure. Purified T cells produce sufficient quantities of RANTES to result in a significant decline in CCR5bright T cell frequency following 16 h of SP exposure (P = 0.03). Meanwhile, NK cells retain the capacity to produce limited amounts of MIP-1α/MIP-1β in response to anti-HIV-1 antibody-dependent stimulation (median, 9.5% MIP-1α+ and/or MIP-1β+), despite the immunosuppressive nature of SP. Although these in vitro experiments suggest that SP-induced CCR5 ligand production results in the loss of surface CCR5 expression on CD4+ T cells, the in vivo implications are unclear. We therefore vaginally exposed five pigtail macaques to SP and found that such exposure resulted in an increase in CCR5+ HIV-1 target cells in three of the animals. The in vivo data support a growing body of evidence suggesting that semen exposure recruits target cells to the vagina that are highly susceptible to HIV-1 infection, which has important implications for HIV-1 transmission and vaccine design. IMPORTANCE The majority of HIV-1 vaccine studies do not take into consideration the impact that semen exposure might have on the mucosal immune system. In this study, we demonstrate that seminal plasma (SP) exposure can alter CCR5 expression on T cells. Importantly, in vitro studies of T cells in culture cannot replicate the conditions under which immune cells might be recruited to the genital mucosa in vivo, leading to potentially erroneous conclusions about the impact of semen on mucosal HIV-1 susceptibility.


1999 ◽  
Vol 73 (3) ◽  
pp. 1828-1834 ◽  
Author(s):  
Mehdi Gasmi ◽  
Jacqueline Glynn ◽  
Ming-Jie Jin ◽  
Douglas J. Jolly ◽  
Jiing-Kuan Yee ◽  
...  

ABSTRACT A number of human immunodeficiency type 1 (HIV-1)-based vectors have recently been shown to transduce nondividing cells in vivo as well as in vitro. However, if these vectors are to be considered for eventual clinical use, a major consideration is to reduce the probability of unintended generation of replication-competent virus. This can be achieved by eliminating viral genetic elements involved in the generation of replication-competent virus without impairing vector production. We have designed a system to transiently produce HIV-1-based vectors by using expression plasmids encoding Gag, Pol, and Tat of HIV-1 under the control of the cytomegalovirus immediate-early promoter. Our data show that the best vector yield is achieved in the presence of the Rev/Rev-responsive element (RRE) system. However, the constitutive transport element of Mason-Pfizer monkey virus can substitute for RRE and Rev at least to some extent, whereas the posttranscriptional regulatory element of human hepatitis B virus appeared to be inefficient. In addition, we show that high-titer virus preparations can be obtained in the presence of sodium butyrate, which activates the expression of both the packaging construct and the vector genome. Finally, our results suggest that efficient infectivity of vectors defective in the accessory proteins Vif, Vpr, Vpu, and Nef depends on the nature of the target cells.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1112 ◽  
Author(s):  
Samy Sid Ahmed ◽  
Nils Bundgaard ◽  
Frederik Graw ◽  
Oliver Fackler

HIV-1 can use cell-free and cell-associated transmission modes to infect new target cells, but how the virus spreads in the infected host remains to be determined. We recently established 3D collagen cultures to study HIV-1 spread in tissue-like environments and applied iterative cycles of experimentation and computation to develop a first in silico model to describe the dynamics of HIV-1 spread in complex tissue. These analyses (i) revealed that 3D collagen environments restrict cell-free HIV-1 infection but promote cell-associated virus transmission and (ii) defined that cell densities in tissue dictate the efficacy of these transmission modes for virus spread. In this review, we discuss, in the context of the current literature, the implications of this study for our understanding of HIV-1 spread in vivo, which aspects of in vivo physiology this integrated experimental–computational analysis takes into account, and how it can be further improved experimentally and in silico.


Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1567-1572 ◽  
Author(s):  
ST Fan ◽  
K Hsia ◽  
TS Edgington

Abstract Cells of monocytic lineage (Mo) persistently infected with human immunodeficiency virus (HIV) have been suspected to be a major reservoir for in vivo transmission of virus to susceptible target cells. Cellular events and mechanisms that upregulate viral gene expression in such cells are important issues. Because the traffic of such cells is central to biodistribution of HIV, we have explored the impact of interaction of endothelium with HIV-1-infected U1 promonocytic cells. Coculturing of U1 with human umbilical endothelial cells (HUVEC) for 24 to 72 hours in the absence of stimulation induced HIV-1 p24 biosynthesis significantly. Antibody-blocking experiments indicated that CD11/CD18 integrins play a role in upregulation of HIV expression elicited by interaction with HUVEC. Engagement of CD11b/CD18 by adherence of U1 to surfaces coated with either the cognate ligand fibrinogen or monoclonal antibody specific for CD11b/CD18 also enhanced p24 biosynthesis. Furthermore, endothelial cells were found to constitutively synthesize and secrete soluble factors that enhanced HIV- 1 synthesis. The enhancing factors, of estimated size 10 to 45 kD, were induced in HUVEC to high levels by monokines or by lipopolysaccharide, resulting in markedly enhanced HIV-1 expression by U1. These endothelial cell-derived HIV-1-enhancing factors consist of, among others, interleukin-6 (IL-6), IL-1 beta, and granulocyte-macrophage CSF (GM-CSF). Our results suggest that activation of HIV biosynthesis in infected Mo via interaction with endothelium may impact significantly on the tissue distribution and pathogenesis of HIV infections.


2020 ◽  
Vol 94 (15) ◽  
Author(s):  
S. Mediouni ◽  
J. A. Jablonski ◽  
S. Tsuda ◽  
A. Barsamian ◽  
C. Kessing ◽  
...  

ABSTRACT Oregano essential oil has long been known for its health-promoting benefits. Here, we report its activity against viral replication. Oregano oil was found to specifically inhibit lentiviruses, such as human and simian immunodeficiency viruses (HIV and SIV), irrespective of virus tropism, but not hepatitis C virus, adenovirus 5 (ADV5), Zika virus, and influenza (H1N1) virus. Oregano oil’s most abundant components, carvacrol and its isomer, thymol, were shown to block virus-target cell fusion while not perturbing other stages of the virus life cycle. We detected changes in virus particle density, suggesting that cholesterol depletion from the HIV-1 envelope membrane reduces virus entry. Furthermore, infection was rescued by adding exogenous cholesterol. The evolution of viral resistance to carvacrol supported this mechanism of action with the identification of mutations in the viral gp41 fusion protein that counteracted cholesterol depletion. In addition, resistance to carvacrol emerged later than typically observed for other clinically used drugs, strengthening its antiviral potential. Structure-activity relationship studies revealed key motifs of carvacrol and thymol required for HIV neutralization and identified previously unknown active analogs. Carvacrol was also shown to additively cooperate with antiretroviral therapy. In sum, oregano oil and improved carvacrol and thymol analogs could be considered to supplement current HIV therapeutics. IMPORTANCE Oregano essential oil has multiple benefits in traditional medicine, cosmetics, and food industries. Carvacrol and its analog, thymol, are well-described components of oregano oil. Here, we show that these compounds inhibit HIV-target cell fusion independently of viral tropism. Our results suggest that carvacrol and thymol alter the cholesterol content of the viral membrane, blocking HIV-1 entry into the target cell. Resistance to carvacrol has selected for viruses with mutations in the viral envelope glycoprotein, gp41. This protein is known for its interaction with cholesterol present in membrane lipid rafts. Together, these results demonstrate the potential of therapies targeting the viral envelope membrane, and oregano oil is a safe supplement to antiretrovirals, potentially delaying disease progression and resistance development.


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