Innate Sensing of HIV-1 by Dendritic Cell-Specific ICAM-3 Grabbing Nonintegrin on Dendritic Cells: Degradation and Presentation Versus Transmission of Virus to T Cells Is Determined by Glycan Composition of Viral Envelope

2017 ◽  
Vol 33 (8) ◽  
pp. 765-767 ◽  
Author(s):  
Muzafar Jan ◽  
Sunil K. Arora
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.


1998 ◽  
Vol 187 (10) ◽  
pp. 1623-1631 ◽  
Author(s):  
Jeanette C. Reece ◽  
Amanda J. Handley ◽  
E. John Anstee ◽  
Wayne A. Morrison ◽  
Suzanne M. Crowe ◽  
...  

Macrophage tropic HIV-1 is predominant during the initial viremia after person to person transmission of HIV-1 (Zhu, T., H. Mo, N. Wang, D.S. Nam, Y. Cao, R.A. Koup, and D.D. Ho. 1993. Science. 261:1179–1181.), and this selection may occur during virus entry and carriage to the lymphoid tissue. Human skin explants were used to model HIV-1 selection that may occur at the skin or mucosal surface. Macrophage tropic, but not T cell line tropic strains of HIV-1 applied to the abraded epidermis were recovered from the cells emigrating from the skin explants. Dermis and epidermis were separated by dispase digestion after virus exposure to determine the site of viral selection within the skin. Uptake and transmission to T cells of all HIV-1 isolates was found with the dermal emigrant cells, but only macrophage tropic virus was transferred by emigrants from the epidermis exposed to HIV-1, indicating selection only within the epidermis. CD3+, CD4+ T cells were found in both the dermal and epidermal emigrant cells. After cell sorting to exclude contaminating T cells, macrophage tropic HIV-1 was found in both the dermal emigrant dendritic cells and in dendritic cells sorted from the epidermal emigrants. These observations suggest that selective infection of the immature epidermal dendritic cells represents the cellular mechanism that limits the initial viremia to HIV-1 that can use the CCR5 coreceptor.


Virology ◽  
2007 ◽  
Vol 362 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Aude Magérus-Chatinet ◽  
Huifeng Yu ◽  
Séverine Garcia ◽  
Elodie Ducloux ◽  
Benoit Terris ◽  
...  

2010 ◽  
Vol 17 (3-4) ◽  
pp. 229-240 ◽  
Author(s):  
Esaki Muthu Shankar ◽  
Karlhans Fru Che ◽  
Davorka Messmer ◽  
Jeffrey D. Lifson ◽  
Marie Larsson

1993 ◽  
Vol 178 (2) ◽  
pp. 633-642 ◽  
Author(s):  
N Bhardwaj ◽  
J W Young ◽  
A J Nisanian ◽  
J Baggers ◽  
R M Steinman

Dendritic cells are potent antigen-presenting cells for several primary immune responses and therefore provide an opportunity for evaluating the amounts of cell-associated antigens that are required for inducing T cell-mediated immunity. Because dendritic cells express very high levels of major histocompatibility complex (MHC) class II products, it has been assumed that high levels of ligands bound to MHC products ("signal one") are needed to stimulate quiescent T cells. Here we describe quantitative aspects underlying the stimulation of human blood T cells by a bacterial superantigen, staphylococcal enterotoxin A (SEA). The advantages of superantigens for quantitative studies of signal one are that these ligands: (a) engage MHC class II and the T cell receptor but do not require processing; (b) are efficiently presented to large numbers of quiescent T cells; and (c) can be pulsed onto dendritic cells before their application to T cells. Thus one can relate amounts of dendritic cell-associated SEA to subsequent lymphocyte stimulation. Using radioiodinated SEA, we noted that dendritic cells can bind 30-200 times more superantigen than B cells and monocytes. Nevertheless, this high SEA binding does not underlie the strong potency of dendritic cells to present antigen to T cells. Dendritic cells can sensitize quiescent T cells, isolated using monoclonals to appropriate CD45R epitopes, after a pulse of SEA that occupies a maximum of 0.1% of surface MHC class II molecules. This corresponds to an average of 2,000 molecules per dendritic cell. At these low doses of bound SEA, monoclonal antibodies to CD3, CD4, and CD28 almost completely block T cell proliferation. In addition to suggesting new roles for MHC class II on dendritic cells, especially the capture and retention of ligands at low external concentrations, the data reveal that primary T cells can generate a response to exceptionally low levels of signal one as long as these are delivered on dendritic cells.


2021 ◽  
Author(s):  
Hongbo Gao ◽  
Ayşe N. Ozantürk ◽  
Qiankun Wang ◽  
Gray H. Harlan ◽  
Aaron J. Schmitz ◽  
...  

The latent reservoir of HIV-1 is a major barrier for viral eradication. Potent HIV-1 broadly neutralizing antibodies (bNabs) have been used to prevent and treat HIV-1 infections in animal models and clinical trials. Combination of bNabs and latency-reversing agents (LRAs) is considered a promising approach for HIV-1 eradication. PCR-based assays that can rapidly and specifically measure singly spliced HIV-1 vpu/env mRNA are needed to evaluate the induction of the viral envelope production at the transcription level and bNab-mediated reservoir clearance. Here we reported a PCR-based method to accurately quantify the production of intracellular HIV-1 vpu/env mRNA. With the vpu/env assay, we determined the LRA combinations that could effectively induce vpu/env mRNA production in CD4+ T cells from ART-treated individuals. None of the tested LRAs were effective alone. A comparison between the quantitative viral outgrowth assay (Q-VOA) and the vpu/env assay showed that vpu/env mRNA production was closely associated with the reactivation of replication-competent HIV-1, suggesting that vpu/env mRNA was mainly produced by intact viruses. Finally, antibody-mediated in vitro killing in HIV-1-infected humanized mice demonstrated that the vpu/env assay could be used to measure the reduction of infected cells in tissues and was more accurate than the commonly used gag-based PCR assay which measured unspliced viral genomic RNA. In conclusion, the vpu/env assay allows convenient and accurate assessment of HIV-1 latency reversal and bNab-mediated therapeutic strategies. Importance HIV-1 persists in individuals on antiretroviral therapy (ART) due to the long-lived cellular reservoirs that contain dormant viruses. Recent discoveries of HIV-1-specific broadly neutralizing antibodies (bNabs) targeting HIV-1 Env protein rekindled the interest in antibody-mediated elimination of latent HIV-1. Latency-reversing agents (LRAs) together with HIV-1 bNabs is a possible strategy to clear residual viral reservoirs, which makes the evaluation of HIV-1 Env expression upon LRA treatment critical. We developed a PCR-based assay to quantify the production of intracellular HIV-1 vpu/env mRNA. Using patient CD4+ T cells, we found that induction of HIV-1 vpu/env mRNA required a combination of different LRAs. Using in vitro, ex vivo and humanized mouse models, we showed that the vpu/env assay could be used to measure antibody efficacy in clearing HIV-1 infection. These results suggest that the vpu/env assay can accurately evaluate HIV-1 reactivation and bNab-based therapeutic interventions.


2003 ◽  
Vol 198 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Vincent Hurez ◽  
Arman Saparov ◽  
Albert Tousson ◽  
Michael J. Fuller ◽  
Takekazu Kubo ◽  
...  

Limited frequencies of T cells express IL-2 in primary antigenic responses, despite activation marker expression and proliferation by most clonal members. To define the basis for restricted IL-2 expression, a videomicroscopic system and IL-2 reporter transgenic model were used to characterize dendritic cell (DC)–T cell interactions. T cells destined to produce IL-2 required prolonged interactions with DCs, whereas most T cells established only transient interactions with DCs and were activated, but did not express IL-2. Extended conjugation of T cells with DCs was not always sufficient to initiate IL-2 expression. Thus, there is intrinsic variability in clonal T cell populations that restricts IL-2 commitment, and prolonged engagement with mature DCs is necessary, but not sufficient, for IL-2 gene transcription.


2020 ◽  
Author(s):  
Yunkai Wang ◽  
Jie Wang ◽  
Lu Han ◽  
Yun Li Shen ◽  
Jie Yun You ◽  
...  

Abstract Background: Triggering receptor expressed on myeloid cells (TREM)-1is identified as a major upstream proatherogenic receptor. However, the cellular processes modulated by TREM-1 in the development of atherosclerosis and plaque destabilization has not been fully elucidated. In this study, we investigated the effects of TREM-1 on dendritic cell maturation and dendritic cell–mediated T-cell activation induced by oxidized low-density lipoprotein (ox-LDL) in atherogenesis. Methods: Human peripheral blood monocytes were differentiated to dendritic cells and stimulated by ox-LDL. Naive autologous T cells were co-cultured with pretreated dendritic cells.The expressionof TREM-1 and the production of inflammatory cytokines were assessed by real-time PCR, western blot and ELISA.The expression of immune factors was determined with FACS to evaluate dendritic cell maturation and T-cell activation. Results: Stimulation with ox-LDL promoted dendritic cell maturation, TREM-1 expression and T-cell activation, and exposure of T cells to ox-LDL-treated dendritic cells induced production of interferon-γ and IL-17. Blocking TREM-1 suppressed dendritic cell maturation with low expression of CD1a, CD40, CD86 and HLA-DR, decreased production of TNF-α, IL-1β, IL-6 and MCP-1, and increased secretion of TGF-β and IL-10. In addition, stimulation of ox-LDL induced miR-155, miR-27, Let-7c and miR-185 expression, whereas inhibition of TREM-1 repressed miRNA-155. Silencing TREM-1 or miRNA-155 increased SOCS1 expression induced by ox-LDL. T cells derived from carotid atherosclerotic plaques or healthy individuals showed similar result patterns. Conclusion: These data suggest that TREM-1 modulates maturation of dendritic cells and activation of plaque T cells induced by ox-LDL, a pivotal player in atherogenesis.


Sign in / Sign up

Export Citation Format

Share Document