scholarly journals Insights into the HIV Latency and the Role of Cytokines

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 137 ◽  
Author(s):  
Joseph Hokello ◽  
Adhikarimayum Lakhikumar Sharma ◽  
Manjari Dimri ◽  
Mudit Tyagi
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Immunological Response ◽  
Hiv Latency ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Treatment Regimens ◽  
Highly Active ◽  
Latent Hiv ◽  
Hiv 1

Human immunodeficiency virus-1 (HIV-1) has the ability to infect latently at the level of individual CD4+ cells. Latent HIV-1 proviruses are transcriptionally silent and immunologically inert, but are still capable of reactivating productive lytic infection following cellular activation. These latent viruses are the main obstacle in the eradication of HIV-1, because current HIV-1 treatment regimens are ineffective against them. Normal immunological response against an antigen activates CD4+ naïve T cells. The activated CD4+ naïve T cells undergo cell cycle, resulting in further transformation and profound proliferation to form effector CD4+ T-cells. Notably, in HIV-1 infected individuals, some of the effector CD4+ T cells get infected with HIV-1. Upon fulfillment of their effector functions, almost all activated CD4+ T cells are committed to apoptosis or programmed cell death, but a miniscule fraction revert to quiescence and become resting memory CD4+ T cells to mediate a rapid immunological response against the same antigen in the future. However, due to the quiescent nature of the resting memory T cells, the integrated HIV-1 becomes transcriptionally silent and acquires a latent phenotype. Following re-exposure to the same antigen, memory cells and integrated HIV-1 are stimulated. The reactivated latent HIV provirus subsequently proceeds through its life cycle and eventually leads to the production of new viral progeny. Recently, many strategies against HIV-1 latency have been developed and some of them have even matured to the clinical level, but none can yet effectively eliminate the latent HIV reservoir, which remains a barrier to HIV-1 cure. Therefore, alternative strategies to eradicate latent HIV need to be considered. This review provides vital knowledge on HIV latency and on strategies to supplement highly active anti-retroviral therapy (HAART) with cytokine-mediated therapeutics for dislodging the latent HIV reservoirs in order to open up new avenues for curing HIV.

CCR5 and CXCR4 Expression on Memory and Naive T Cells in HIV-1 Infection and Response to Highly Active Antiretroviral Therapy

2001 ◽  
Vol 27 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Janet K. A. Nicholson ◽  
Sandra W. Browning ◽  
Richard L. Hengel ◽  
Edward Lew ◽  
Laura E. Gallagher ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Cxcr4 Expression ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Highly Active ◽  
Hiv 1

scholarly journals A two-color haploid genetic screen identifies novel host factors involved in HIV latency

2021 ◽  
Author(s):  
Michael D Röling ◽  
Mahsa Mollapour Sisakht ◽  
Enrico Ne ◽  
Panagiotis Moulos ◽  
Mateusz Stoszko ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Cd4 T Cells ◽  
Genetic Screen ◽  
Host Factors ◽  
Hiv Latency ◽  
Novel Host ◽  
Latent Hiv ◽  
Hiv 1

AbstractTo identify novel host factors as putative targets to reverse HIV latency, we performed an insertional mutagenesis genetic screen in a latently HIV-1-infected pseudo-haploid KBM7 cell line (Hap-Lat). Following mutagenesis, insertions were mapped to the genome and bioinformatic analysis resulted in the identification of 69 candidate host genes involved in maintaining HIV-1 latency. A select set of candidate genes was functionally validated using shRNA mediated depletion in latent HIV-1 infected J-Lat A2 and 11.1 T cell lines. We confirmed ADK, CHD9, CMSS1, EVI2B, EXOSC8, FAM19A, GRIK5, IRF2BP2, NF1, and USP15 as novel host factors involved in the maintenance of HIV latency. Chromatin immunoprecipitation assays indicated that CHD9, a Chromodomain Helicase DNA-binding protein, maintains HIV latency via direct association with the HIV 5’LTR, and its depletion results in increased histone acetylation at the HIV-1 promoter, concomitant with HIV-1 latency reversal. FDA-approved inhibitors 5-Iodotubercidin, Trametinib, and Topiramate, targeting ADK, NF1, and GRIK5, respectively were characterized for their latency reversal potential. While 5-Iodotubercidin exhibited significant cytotoxicity in both J-Lat and primary CD4+ T cells, Trametinib reversed latency in J-Lat cells but not in latently HIV-1-infected primary CD4+ T cells. Crucially, Topiramate reversed latency in cell-line models and latently infected primary CD4+ T cells, without inducing T cell activation or significant toxicity. Thus, using an adaptation of a haploid forward genetic screen, we identified novel and druggable host factors contributing to HIV-1 latency.ImportanceA reservoir of latent HIV-1-infected cells persists in the presence of combination antiretroviral therapy (cART), representing a major obstacle for viral eradication. Reactivation of the latent HIV-1 provirus is part of curative strategies which aim to promote clearance of the infected cells. Using a two-color haploid screen, we identified 69 candidate genes as latency maintaining host factors and functionally validated a subset of 10 of those in additional T-cell based cell line models of HIV-1 latency. We further demonstrated that CHD9 is associated with HIV-1’s promoter, the 5’LTR while this association is lost upon reactivation. Additionally, we characterized the latency reversal potential of FDA compounds targeting ADK, NF1, and GRIK5 and identify the GRIK5 inhibitor Topiramate as a viable latency reversal agent with clinical potential.

scholarly journals A Dichotomy in Cortical Actin and Chemotactic Actin Activity between Human Memory and Naive T Cells Contributes to Their Differential Susceptibility to HIV-1 Infection

2012 ◽  
Vol 287 (42) ◽  
pp. 35455-35469 ◽  
Author(s):  
Weifeng Wang ◽  
Jia Guo ◽  
Dongyang Yu ◽  
Paul J. Vorster ◽  
WanJun Chen ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Differential Susceptibility ◽  
Human Memory ◽  
Actin Dynamics ◽  
Cortical Actin ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Memory Cd4 T Cells ◽  
Hiv 1

Human memory and naive CD4 T cells can mainly be identified by the reciprocal expression of the CD45RO or CD45RA isoforms. In HIV-1 infection, blood CD45RO memory CD4 T cells are preferentially infected and serve as a major viral reservoir. The molecular mechanism dictating this differential susceptibility to HIV-1 remains largely obscure. Here, we report that the different susceptibility of memory and naive T cells to HIV is not determined by restriction factors such as Apobec3G or BST2. However, we observed a phenotypic distinction between human CD45RO and CD45RA resting CD4 T cells in their cortical actin density and actin dynamics. CD45RO CD4 T cells possess a higher cortical actin density and can be distinguished as CD45RO+Actinhigh. In contrast, CD45RA T cells are phenotypically CD45RA+Actinlow. In addition, the cortical actin in CD45RO memory CD4 T cells is more dynamic and can respond to low dosages of chemotactic induction by SDF-1, whereas that of naive cells cannot, despite a similar level of the chemokine receptor CXCR4 present on both cells. We further demonstrate that this difference in the cortical actin contributes to their differential susceptibility to HIV-1; resting memory but not naive T cells are highly responsive to HIV-mediated actin dynamics that promote higher levels of viral entry and early DNA synthesis in resting memory CD4 T cells. Furthermore, transient induction of actin dynamics in resting naive T cells rescues HIV latent infection following CD3/CD28 stimulation. These results suggest a key role of chemotactic actin activity in facilitating HIV-1 latent infection of these T cell subsets.

CCR5 and CXCR4 Expression on Memory and Naive T Cells in HIV-1 Infection and Response to Highly Active Antiretroviral Therapy

2001 ◽  
Vol 27 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Janet K. A. Nicholson ◽  
Sandra W. Browning ◽  
Richard L. Hengel ◽  
Edward Lew ◽  
Laura E. Gallagher ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Cxcr4 Expression ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Highly Active ◽  
Hiv 1

scholarly journals Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution

Blood ◽  
2012 ◽  
Vol 120 (9) ◽  
pp. 1856-1867 ◽  
Author(s):  
Ming Zeng ◽  
Mirko Paiardini ◽  
Jessica C. Engram ◽  
Greg J. Beilman ◽  
Jeffrey G. Chipman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antiretroviral Therapy ◽  
Cd4 T Cells ◽  
Lymphoid Tissue ◽  
T Cell Subsets ◽  
Tissue Structure ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Hiv 1

Abstract Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1–infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution.

scholarly journals Response of naive antigen-specific CD4+ T cells in vitro: characteristics and antigen-presenting cell requirements.

1992 ◽  
Vol 176 (5) ◽  
pp. 1431-1437 ◽  
Author(s):  
M Croft ◽  
D D Duncan ◽  
S L Swain
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 Cells ◽  
Peptide Antigen ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Antigen Presenting

Because of the low frequency of T cells for any particular soluble protein antigen in unprimed animals, the requirements for naive T cell responses in specific antigens have not been clearly delineated and they have been difficult to study in vitro. We have taken advantage of mice transgenic for the V beta 3/V alpha 11 T cell receptor (TCR), which can recognize a peptide of cytochrome c presented by IEk. 85-90% of CD4+ T cells in these mice express the transgenic TCR, and we show that almost all such V beta 3/V alpha 11 receptor-positive cells have a phenotype characteristic of naive T cells, including expression of high levels of CD45RB, high levels of L-selectin (Mel-14), low levels of CD44 (Pgp-1), and secretion of interleukin 2 (IL-2) as the major cytokine. Naive T cells, separated on the basis of CD45RB high expression, gave vigorous responses (proliferation and IL-2 secretion) to peptide antigen presented in vitro by a mixed antigen-presenting cell population. At least 50% of the T cell population appeared to respond, as assessed by blast transformation, entry into G1, and expression of increased levels of CD44 by 24 h. Significant contributions to the response by contaminating memory CD4+ cells were ruled out by demonstrating that the majority of the CD45RB low, L-selectin low, CD44 high cells did not express the V beta 3/V alpha 11 TCR and responded poorly to antigen. We find that proliferation and IL-2 secretion of the naive CD4 cells is minimal when resting B cells present peptide antigen, and that both splenic and bone marrow-derived macrophages are weak stimulators. Naive T cells did respond well to high numbers of activated B cells. However, dendritic cells were the most potent stimulators of proliferation and IL-2 secretion at low cell numbers, and were far superior inducers of IL-2 at higher numbers. These studies establish that naive CD4 T cells can respond vigorously to soluble antigen and indicate that maximal stimulation can be achieved by presentation of antigen on dendritic cells. This model should prove very useful in further investigations of activation requirements and functional characteristics of naive helper T cells.

scholarly journals CRTAM determines the CD4+ cytotoxic T lymphocyte lineage

2015 ◽  
Vol 213 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Arata Takeuchi ◽  
Mohamed El Sherif Gadelhaq Badr ◽  
Kosuke Miyauchi ◽  
Chitose Ishihara ◽  
Reiko Onishi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cytotoxic Activity ◽  
Cd4 T Cells ◽  
Intracellular Signaling ◽  
Ectopic Expression ◽  
T Cell Subsets ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Ifn Γ

Naive T cells differentiate into various effector T cells, including CD4+ helper T cell subsets and CD8+ cytotoxic T cells (CTL). Although cytotoxic CD4+ T cells (CD4+CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4+ T cells that express class I–restricted T cell–associated molecule (CRTAM) upon activation possesses the characteristics of both CD4+ and CD8+ T cells. CRTAM+ CD4+ T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM+ T cells are the precursor of CD4+CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4+CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM+ T cells traffic to mucosal tissues and inflammatory sites and developed into CD4+CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4+CTL through the induction of Eomes and CTL-related gene.

scholarly journals Tenofovir-Based Highly Active Antiretroviral Therapy Is Associated with Superior CD4 T Cells Repopulation Compared to Zidovudine-Based HAART in HIV 1 Infected Adults

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Vitus Sambo Badii ◽  
Kwame Ohene Buabeng ◽  
Thomas Agyarko Poku ◽  
Arnold Donkor Forkuo ◽  
Bright Boafo Boamah ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Highly Active Antiretroviral Therapy ◽  
Cd4 T Cells ◽  
Scientific Data ◽  
Highly Active ◽  
Median Period ◽  
Hiv 1 ◽  
Count Change ◽  
Zidovudine Regimen

Tenofovir-based highly active antiretroviral therapy (HAART) is one of the preferred first-line therapies in the management of HIV 1 infection. Ghana has since 2014 adopted this recommendation; however there is paucity of scientific data that reflects the safety and efficacy of the tenofovir-based therapy compared to zidovudine in the Ghanaian health system. This study sought to assess the comparative immune reconstitution potential between tenofovir and zidovudine-based HAART regimens, which includes lamivudine and efavirenz in combination therapy. It also aimed to investigate the adverse drug reactions/events (ADREs) associated with pharmacotherapy with these agents in a total of 106 HAART naïve HIV patients. The study included 80 patients in the tenofovir cohort while 26 patients were on the zidovudine regimen. The occurrence of HIV comorbidities profile was assessed at diagnosis and throughout the study period. The baseline CD4 T cells count of the participants was also assessed at diagnosis and repeated at a median period of five months (range 4–6 months), after commencing treatment with either tenofovir- or zidovudine-based HAART. After five months of the HAART, the tenofovir cohort recorded higher CD4 T cell count change from baseline compared to the zidovudine cohort (p<0.0001). The patients on the tenofovir-based HAART and female sex however appeared to be associated with more multiple ADREs.

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