scholarly journals The Synthetic Immunomodulator Murabutide Controls Human Immunodeficiency Virus Type 1 Replication at Multiple Levels in Macrophages and Dendritic Cells

2000 ◽  
Vol 74 (17) ◽  
pp. 7794-7802 ◽  
Author(s):  
Edith C. A. Darcissac ◽  
Marie-José Truong ◽  
Joëlle Dewulf ◽  
Yves Mouton ◽  
André Capron ◽  
...  

ABSTRACT Macrophages and dendritic cells are known to play an important role in the establishment and persistence of human immunodeficiency virus (HIV) infection. Besides antiretroviral therapy, several immune-based interventions are being evaluated with the aim of achieving better control of virus replication in reservoir cells. Murabutide is a safe synthetic immunomodulator presenting a capacity to enhance nonspecific resistance against viral infections and to target cells of the reticuloendothelial system. In this study, we have examined the ability of Murabutide to control HIV type 1 (HIV-1) replication in acutely infected monocyte-derived macrophages (MDMs) and dendritic cells (MDDCs). Highly significant suppression of viral replication was consistently observed in Murabutide-treated cultures of both cell types. Murabutide did not affect virus entry, reverse transcriptase activity, or early proviral DNA formation in the cytoplasm of infected cells. However, treated MDMs and MDDCs showed a dramatic reduction in nuclear viral two-long terminal repeat circular form and viral mRNA transcripts. This HIV-1-suppressive activity was not mediated by inhibiting cellular DNA synthesis or by activating p38 mitogen-activated protein kinase. Furthermore, Murabutide-stimulated cells expressed reduced CD4 and CCR5 receptors and secreted high levels of β-chemokines, although neutralization of the released chemokines did not alter the HIV-1-suppressive activity of Murabutide. These results provide evidence that a clinically acceptable immunomodulator can activate multiple effector pathways in macrophages and in dendritic cells, rendering them nonpermissive for HIV-1 replication.

2007 ◽  
Vol 81 (14) ◽  
pp. 7559-7570 ◽  
Author(s):  
Nuria Izquierdo-Useros ◽  
Julià Blanco ◽  
Itziar Erkizia ◽  
Maria Teresa Fernández-Figueras ◽  
Francesc E. Borràs ◽  
...  

ABSTRACT Dendritic cells (DCs) are specialized antigen-presenting cells. However, DCs exposed to human immunodeficiency virus type 1 (HIV-1) are also able to transmit a vigorous cytopathic infection to CD4+ T cells, a process that has been frequently related to the ability of DC-SIGN to bind HIV-1 envelope glycoproteins. The maturation of DCs can increase the efficiency of HIV-1 transmission through trans infection. We aimed to comparatively study the effect of maturation in monocyte-derived DCs (MDDCs) and blood-derived myeloid DCs during the HIV-1 capture process. In vitro capture and transmission of envelope-pseudotyped HIV-1 and its homologous replication-competent virus to susceptible target cells were assessed by p24gag detection, luciferase activity, and both confocal and electron microscopy. Maturation of MDDCs or myeloid DCs enhanced the active capture of HIV-1 in a DC-SIGN- and viral envelope glycoprotein-independent manner, increasing the life span of trapped virus. Moreover, higher viral transmission of mature DCs to CD4+ T cells was highly dependent on active viral capture, a process mediated through cholesterol-enriched domains. Mature DCs concentrated captured virus in a single large vesicle staining for CD81 and CD63 tetraspanins, while immature DCs lacked these structures, suggesting different intracellular trafficking processes. These observations help to explain the greater ability of mature DCs to transfer HIV-1 to T lymphocytes, a process that can potentially contribute to the viral dissemination at lymph nodes in vivo, where viral replication takes place and there is a continuous interaction between susceptible T cells and mature DCs.


2007 ◽  
Vol 81 (17) ◽  
pp. 8933-8943 ◽  
Author(s):  
Jian-Hua Wang ◽  
Alicia M. Janas ◽  
Wendy J. Olson ◽  
Li Wu

ABSTRACT Dendritic cells (DCs) potently stimulate the transmission of human immunodeficiency virus type 1 (HIV-1) to CD4+ T cells. Immature DCs (iDCs) located in submucosal tissues can capture HIV-1 and migrate to lymphoid tissues, where they become mature DCs (mDCs) for effective antigen presentation. DC maturation promotes HIV-1 transmission; however, the underlying mechanisms remain unclear. Here we have compared monocyte-derived iDCs and mDCs for their efficiencies and mechanisms of HIV-1 transmission. We have found that mDCs significantly facilitate HIV-1 endocytosis and efficiently concentrate HIV-1 at virological synapses, which contributes to mDC-enhanced viral transmission, at least in part. mDCs were more efficient than iDCs in transferring HIV-1 to various types of target cells independently of C-type lectins, which partially accounted for iDC-mediated HIV-1 transmission. Efficient HIV-1 trans-infection mediated by iDCs and mDCs required contact between DCs and target cells. Moreover, rapid HIV-1 degradation occurred in both iDCs and mDCs, which correlated with the lack of HIV-1 retention-mediated long-term viral transmission. Our results provide new insights into the mechanisms underlying DC-mediated HIV-1 transmission, suggesting that HIV-1 exploits mDCs to facilitate its dissemination within lymphoid tissues.


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.


2008 ◽  
Vol 83 (6) ◽  
pp. 2778-2782 ◽  
Author(s):  
Corinne Barat ◽  
Caroline Gilbert ◽  
Michel J. Tremblay

ABSTRACT Dendritic cells (DC) are considered to be important contributors to human immunodeficiency virus type 1 (HIV-1) transmission and pathogenesis. As the first target cells in mucosal tissues, they can be become productively infected and can also capture virions and transfer them efficiently to CD4+ T cells located within lymphoid tissues. Resting CD4+ T cells appear to be another major target of HIV-1 in vivo, yet several blocks restrict replication in such cells. We report here that physical contact between virus-infected quiescent CD4+ T cells and uninfected autologous immature DC in the absence of any foreign antigen relieves these restrictions, allowing a highly productive HIV-1 replication.


2005 ◽  
Vol 49 (12) ◽  
pp. 4911-4919 ◽  
Author(s):  
Julie M. Strizki ◽  
Cecile Tremblay ◽  
Serena Xu ◽  
Lisa Wojcik ◽  
Nicole Wagner ◽  
...  

ABSTRACT Inhibiting human immunodeficiency virus type 1 (HIV-1) infection by blocking the host cell coreceptors CCR5 and CXCR4 is an emerging strategy for antiretroviral therapy. Currently, several novel coreceptor inhibitors are being developed in the clinic, and early results have proven promising. In this report, we describe a novel CCR5 antagonist, vicriviroc (formerly SCH-D or SCH 417690), with improved antiviral activity and pharmacokinetic properties compared to those of SCH-C, a previously described CCR5 antagonist. Like SCH-C, vicriviroc binds specifically to the CCR5 receptor and prevents infection of target cells by CCR5-tropic HIV-1 isolates. In antiviral assays, vicriviroc showed potent, broad-spectrum activity against genetically diverse and drug-resistant HIV-1 isolates and was consistently more active than SCH-C in inhibiting viral replication. This compound demonstrated synergistic anti-HIV activity in combination with drugs from all other classes of approved antiretrovirals. Competition binding assays revealed that vicriviroc binds with higher affinity to CCR5 than SCH-C. Functional assays, including inhibition of calcium flux, guanosine 5′-[35S]triphosphate exchange, and chemotaxis, confirmed that vicriviroc acts as a receptor antagonist by inhibiting signaling of CCR5 by chemokines. Finally, vicriviroc demonstrated diminished affinity for the human ether a-go-go related gene transcript ion channel compared to SCH-C, suggesting a reduced potential for cardiac effects. Vicriviroc represents a promising new candidate for the treatment of HIV-1 infection.


2001 ◽  
Vol 75 (16) ◽  
pp. 7621-7628 ◽  
Author(s):  
Julianna Lisziewicz ◽  
Dmitry I. Gabrilovich ◽  
Georg Varga ◽  
Jianqing Xu ◽  
Philip D. Greenberg ◽  
...  

ABSTRACT A novel technology combining replication- and integration-defective human immunodeficiency virus type 1 (HIV-1) vectors with genetically modified dendritic cells was developed in order to induce T-cell immunity. We introduced the vector into dendritic cells as a plasmid DNA using polyethylenimine as the gene delivery system, thereby circumventing the problem of obtaining viral vector expression in the absence of integration. Genetically modified dendritic cells (GMDC) presented viral epitopes efficiently, secreted interleukin 12, and primed both CD4+ and CD8+ HIV-specific T cells capable of producing gamma interferon and exerting potent HIV-1-specific cytotoxicity in vitro. In nonhuman primates, subcutaneously injected GMDC migrated into the draining lymph node at an unprecedentedly high rate and expressed the plasmid DNA. The animals presented a vigorous HIV-specific effector cytotoxic-T-lymphocyte (CTL) response as early as 3 weeks after a single immunization, which later developed into a memory CTL response. Interestingly, antibodies did not accompany these CTL responses, indicating that GMDC can induce a pure Th1 type of immune response. Successful induction of a broad and long-lasting HIV-specific cellular immunity is expected to control virus replication in infected individuals.


2002 ◽  
Vol 76 (15) ◽  
pp. 7812-7821 ◽  
Author(s):  
Rogier W. Sanders ◽  
Esther C. de Jong ◽  
Christopher E. Baldwin ◽  
Joost H. N. Schuitemaker ◽  
Martien L. Kapsenberg ◽  
...  

ABSTRACT Dendritic cells (DC) support human immunodeficiency virus type 1 (HIV-1) transmission by capture of the virus particle in the mucosa and subsequent transport to the draining lymph node, where HIV-1 is presented to CD4+ Th cells. Virus transmission involves a high-affinity interaction between the DC-specific surface molecule DC-SIGN and the viral envelope glycoprotein gp120 and subsequent internalization of the virus, which remains infectious. The mechanism of viral transmission from DC to T cells is currently unknown. Sentinel immature DC (iDC) develop into Th1-promoting effector DC1 or Th2-promoting DC2, depending on the activation signals. We studied the ability of these effector DC subsets to support HIV-1 transmission in vitro. Compared with iDC, virus transmission is greatly upregulated for the DC1 subset, whereas DC2 cells are inactive. Increased transmission by DC1 correlates with increased expression of ICAM-1, and blocking studies confirm that ICAM-1 expression on DC is important for HIV transmission. The ICAM-1-LFA-1 interaction is known to be important for immunological cross talk between DC and T cells, and our results indicate that this cell-cell contact is exploited by HIV-1 for efficient transmission.


2009 ◽  
Vol 90 (11) ◽  
pp. 2777-2787 ◽  
Author(s):  
Claudia Muratori ◽  
Eliana Ruggiero ◽  
Antonella Sistigu ◽  
Roberta Bona ◽  
Maurizio Federico

Sexual transmission is now the most frequent means of diffusion of human immunodeficiency virus type 1 (HIV-1). Even if the underlying mechanism is still largely unknown, there is a consensus regarding the key role played by mucosal dendritic cells (DCs) in capturing HIV through contact with infected subepithelial lymphocytes, and their capacity to spread HIV by trans-infection. We found that HIV protease inhibitors (PIs) reduced virion endocytosis strongly in monocyte-derived immature (i) DCs contacting HIV-1-infected cells, and that this phenomenon led to dramatically impaired trans-infection activity. This inhibitory effect was not mediated by the block of viral protease activity, as it was also operative when donor cells were infected with a PI-resistant HIV-1 strain. The block of virus maturation imposed by PIs did not correlate with significant variations in the levels of virus expression in donor cells or of Gag/Env virion incorporation. Also, PIs did not affect the endocytosis activity of DCs. In contrast, we noticed that PI treatment inhibited the formation of cell–cell conjugates whilst reducing the expression of ICAM-1 in target iDCs. Our results contribute to a better delineation of the mechanisms underlying HIV-1 trans-infection activity in DCs, whilst having implications for the development of new anti-HIV microbicide strategies.


2004 ◽  
Vol 78 (3) ◽  
pp. 1324-1332 ◽  
Author(s):  
Yoshiyuki Yokomaku ◽  
Hideka Miura ◽  
Hiroko Tomiyama ◽  
Ai Kawana-Tachikawa ◽  
Masafumi Takiguchi ◽  
...  

ABSTRACT Investigating escape mechanisms of human immunodeficiency virus type 1 (HIV-1) from cytotoxic T lymphocytes (CTLs) is essential for understanding the pathogenesis of HIV-1 infection and developing effective vaccines. To study the processing and presentation of known CTL epitopes, we prepared Epstein-Barr virus-transformed B cells that endogenously express the gag gene of six field isolates by adopting an env/nef-deletion HIV-1 vector pseudotyped with vesicular stomatitis virus G protein and then tested them for the recognition by Gag epitope-specific CTL lines or clones. We observed that two field variants, SLFNTVAVL and SVYNTVATL, of an A*0201-restricted Gag CTL epitope SLYNTVATL, and three field variants, KYRLKHLVW, QYRLKHIVW, and RYRLKHLVW, of an A24-restricted Gag CTL epitope KYKLKHIVW escaped from being killed by the CTL lines, despite the fact that they were recognized when the synthetic peptides corresponding to these variant sequences were exogenously loaded onto the target cells. Thus, their escape is likely due to the changes that occur during the processing and presentation of epitopes in the infected cells. Mutations responsible for this mode of escape were located within the epitope regions rather than the flanking regions, and such mutations did not influence the virus replication. The results suggest that the impaired antigen processing and presentation often occur in HIV-1 field isolates and thus are one of the major mechanisms that enable HIV-1 to escape from CTL recognition. We emphasize the importance of testing HIV-1 variants in an endogenous expression system.


1990 ◽  
Vol 172 (4) ◽  
pp. 1151-1158 ◽  
Author(s):  
B Ardman ◽  
M A Sikorski ◽  
M Settles ◽  
D E Staunton

Sera from human immunodeficiency virus type 1 (HIV-1)-infected and -noninfected individuals were screened for antibodies that could bind to native T cell differentiation antigens. Antibodies that could immunoprecipitate CD43 (sialophorin, leukosialin) from a T cell lymphoma line were detected in sera from 27% of patients, and antibodies that could bind specifically to transfected cells expressing CD43 were detected in 47% of patients. The anti-CD43 antibodies were related to HIV-1 infection in that no patients with other chronic viral infections or systemic lupus erythematosus contained such antibodies in their sera. The anti-CD43 autoantibodies bound to a partially sialylated form of CD43 expressed by normal human thymocytes, but not by normal, circulating T lymphocytes. However, the determinant(s) recognized by the anti-CD43 autoantibodies was present on a large proportion of circulating T lymphocytes, but masked from antibody recognition by sialic acid residues. These results demonstrate that HIV-1 infection is specifically associated with the production of autoantibodies that bind to a native T cell surface antigen.


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