1
|
Chiappini E, Bianconi M, Dalzini A, Petrara MR, Galli L, Giaquinto C, De Rossi A. Accelerated aging in perinatally HIV-infected children: clinical manifestations and pathogenetic mechanisms. Aging (Albany NY) 2019; 10:3610-3625. [PMID: 30418933 PMCID: PMC6286860 DOI: 10.18632/aging.101622] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/27/2018] [Indexed: 12/12/2022]
Abstract
Background: Premature aging and related diseases have been documented in HIV-infected adults. Data are now emerging also regarding accelerated aging process in HIV-infected children. Methods: A narrative review was performed searching studies on PubMed published in English language in 2004-2017, using appropriate key words, including “aging”, “children”, “HIV”, “AIDS”, “immunosenescence”, “pathogenesis”, “clinical conditions”. Results: Premature immunosenescence phenotype of B and T cells in HIV-infected children is mediated through immune system activation and chronic inflammation. Ongoing inflammation processes have been documented by increased levels of pathogen-associated molecular patterns (PAMPS), increased mitochondrial damage, higher levels of pro-inflammatory cytokines, and a positive correlation between sCD14 levels and percentages of activated CD8+ cells. Other reported features of premature aging include cellular replicative senescence, linked to an accelerated telomeres shortening. Finally, acceleration of age-associated methylation pattern and other epigenetic modifications have been described in HIV-infected children. All these features may favor the clinical manifestations related to premature aging. Lipid and bone metabolism, cancers, cardiovascular, renal, and neurological systems should be carefully monitored, particularly in children with detectable viremia and/or with CD4/CD8 ratio inversion. Conclusion: Aging processes in children with HIV infection impact their quality and length of life. Further studies regarding the mechanisms involved in premature aging are needed to search for potential targets of treatment.
Collapse
Affiliation(s)
- Elena Chiappini
- Infectious Disease Unit, Meyer Children's Hospital, Department of Science Health, University of Florence, Florence, Italy
| | - Martina Bianconi
- Infectious Disease Unit, Meyer Children's Hospital, Department of Science Health, University of Florence, Florence, Italy
| | - Annalisa Dalzini
- Section of Oncology and Immunology, Department of Surgery, Oncology and Gastroenterology, Unit of viral Oncology and AIDS Reference Center, University of Padova, Padova, Italy
| | - Maria Raffaella Petrara
- Section of Oncology and Immunology, Department of Surgery, Oncology and Gastroenterology, Unit of viral Oncology and AIDS Reference Center, University of Padova, Padova, Italy
| | - Luisa Galli
- Infectious Disease Unit, Meyer Children's Hospital, Department of Science Health, University of Florence, Florence, Italy
| | - Carlo Giaquinto
- Department of Mother and Child Health, University of Padova, Padova, Italy
| | - Anita De Rossi
- Section of Oncology and Immunology, Department of Surgery, Oncology and Gastroenterology, Unit of viral Oncology and AIDS Reference Center, University of Padova, Padova, Italy.,Istituto Oncologico Veneto IOV-IRCCS, Padova, Italy
| |
Collapse
|
2
|
Saberi S, Kalloger SE, Zhu MMT, Sattha B, Maan EJ, van Schalkwyk J, Money DM, Côté HCF. Dynamics of leukocyte telomere length in pregnant women living with HIV, and HIV-negative pregnant women: A longitudinal observational study. PLoS One 2019; 14:e0212273. [PMID: 30840638 PMCID: PMC6402636 DOI: 10.1371/journal.pone.0212273] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 01/30/2019] [Indexed: 12/25/2022] Open
Abstract
Background HIV-mediated inflammation and immune activation can accelerate telomere attrition. In addition, antiretrovirals can inhibit telomerase, possibly shortening telomeres. We examined the longitudinal dynamics of leukocyte telomere length (LTL) during pregnancy in a unique cohort of women living with HIV (WLWH) treated with combination antiretroviral therapy (cART), and HIV-negative control women. Methods Blood was collected at three visits during pregnancy, at 13–23, >23–30, and >30–40 weeks of gestation, and for WLWH only, at 6 weeks post-partum. LTL was measured by qPCR and both cross-sectional and longitudinal (MANOVA) models were used to examine possible predictors of LTL among participants who attended all three visits during pregnancy. Results Among WLWH (n = 64) and HIV-negative women (n = 41), within participant LTL were correlated throughout pregnancy (p<0.001). LTL was shorter among WLWH at first visit, but this difference waned by the second visit. WLWH who discontinued cART post-partum experienced a decrease in LTL. Longitudinally, LTL was similar in both groups and increased as gestation progressed, a change that was more pronounced among women under 35 years. Among WLWH, both smoking throughout pregnancy (p = 0.04) and receiving a ritonavir-boosted protease inhibitor-based regimen (p = 0.03) were independently associated with shorter LTL. Conclusions LTL increases as pregnancy progresses; the reasons for this are unknown but may relate to changes in blood volume, hormones, and/or cell subset distribution. While our observations need confirmation in an independent cohort, our data suggest that although some cART regimens may influence LTL, being on cART appears overall protective and that stopping cART post-partum may negatively impact LTL. The effect of smoking on LTL is clearly negative, stressing the importance of smoking cessation.
Collapse
Affiliation(s)
- Sara Saberi
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steve E. Kalloger
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mayanne M. T. Zhu
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Beheroze Sattha
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Evelyn J. Maan
- British Columbia Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada
| | - Julianne van Schalkwyk
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada
- Women’s Health Research Institute, Vancouver, British Columbia, Canada
| | - Deborah M. Money
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada
- Women’s Health Research Institute, Vancouver, British Columbia, Canada
| | - Hélène C. F. Côté
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Women’s Health Research Institute, Vancouver, British Columbia, Canada
- Centre for Blood Research, Vancouver, British Columbia, Canada
- * E-mail:
| | | |
Collapse
|
3
|
Piekna-Przybylska D, Maggirwar SB. CD4+ memory T cells infected with latent HIV-1 are susceptible to drugs targeting telomeres. Cell Cycle 2018; 17:2187-2203. [PMID: 30198385 DOI: 10.1080/15384101.2018.1520568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The population of HIV reservoir in infected person is very small, but extremely long-lived and is a major obstacle for an HIV cure. We previously showed that cells with established HIV latency have deficiencies in DNA damage response (DDR). Here, we investigated ability of HIV-1 to interfere with telomere maintenance, and the effects of targeting telomeres on latently infected cells. Our results show that telomeres are elongated in cultured primary memory CD4 + T cells (TCM) after HIV-1 infection and when virus latency is established. Similarly, much longer telomeres were found in several Jurkat-derived latently infected cell lines, indicating that virus stimulates telomere elongation. Exposing primary CD4+ TCM cells to BRACO19, an agent targeting telomeres, resulted in a higher rate of apoptosis for infected cultures at day 3 post-infection, during HIV-1 latency and for PMA-stimulated cultures with low level of HIV-1 reactivation. Importantly, BRACO19 induced apoptosis in infected cells with potency similar to etoposide and camptothecin, whereas uninfected cells were less affected by BRACO19. We also determined that apoptosis induced by BRACO19 is not caused by telomeres shortening, but is related to formation of gamma-H2AX, implicating DNA damage or uncapping of telomeres, which triggers genome instability. In conclusion, our results indicate that HIV-1 stimulates telomere elongation during latency, suggesting that HIV reservoir has greater capacity for clonal expansion and extended lifespan. Higher rates of apoptosis in response to BRACO19 treatment suggest that HIV reservoirs are more susceptible to targeting telomere maintenance and to inhibitors targeting DDR, which is also involved in stabilizing telomeres.
Collapse
Affiliation(s)
- Dorota Piekna-Przybylska
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
| | - Sanjay B Maggirwar
- a Department of Microbiology and Immunology, School of Medicine and Dentistry , University of Rochester , Rochester , NY , USA
| |
Collapse
|
4
|
Piekna-Przybylska D, Sharma G, Maggirwar SB, Bambara RA. Deficiency in DNA damage response, a new characteristic of cells infected with latent HIV-1. Cell Cycle 2017; 16:968-978. [PMID: 28388353 DOI: 10.1080/15384101.2017.1312225] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Viruses can interact with host cell molecules responsible for the recognition and repair of DNA lesions, resulting in dysfunctional DNA damage response (DDR). Cells with inefficient DDR are more vulnerable to therapeutic approaches that target DDR, thereby raising DNA damage to a threshold that triggers apoptosis. Here, we demonstrate that 2 Jurkat-derived cell lines with incorporated silent HIV-1 provirus show increases in DDR signaling that responds to formation of double strand DNA breaks (DSBs). We found that phosphorylation of histone H2AX on Ser139 (gamma-H2AX), a biomarker of DSBs, and phosphorylation of ATM at Ser1981, Chk2 at Thr68, and p53 at Ser15, part of signaling pathways associated with DSBs, are elevated in these cells. These results indicate a DDR defect even though the virus is latent. DDR-inducing agents, specifically high doses of nucleoside RT inhibitors (NRTIs), caused greater increases in gamma-H2AX levels in latently infected cells. Additionally, latently infected cells are more susceptible to long-term exposure to G-quadruplex stabilizing agents, and this effect is enhanced when the agent is combined with an inhibitor targeting DNA-PK, which is crucial for DSB repair and telomere maintenance. Moreover, exposing these cells to the cancer drug etoposide resulted in formation of DSBs at a higher rate than in un-infected cells. Similar effects of etoposide were also observed in population of primary memory T cells infected with latent HIV-1. Sensitivity to these agents highlights a unique vulnerability of latently infected cells, a new feature that could potentially be used in developing therapies to eliminate HIV-1 reservoirs.
Collapse
Affiliation(s)
- Dorota Piekna-Przybylska
- a Department of Microbiology and Immunology , School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA
| | - Gaurav Sharma
- b Department of Electrical and Computer Engineering , University of Rochester , Rochester , NY , USA
| | - Sanjay B Maggirwar
- a Department of Microbiology and Immunology , School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA
| | - Robert A Bambara
- a Department of Microbiology and Immunology , School of Medicine and Dentistry, University of Rochester , Rochester , NY , USA
| |
Collapse
|
5
|
Abstract
Supplemental Digital Content is available in the text Several pieces of evidence indicate that HIV-infected adults undergo premature aging. The effect of HIV and antiretroviral therapy (ART) exposure on the aging process of HIV-infected children may be more deleterious since their immune system coevolves from birth with HIV.
Collapse
|
6
|
Eradication of HIV-1 from the macrophage reservoir: an uncertain goal? Viruses 2015; 7:1578-98. [PMID: 25835530 PMCID: PMC4411666 DOI: 10.3390/v7041578] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/16/2015] [Accepted: 03/24/2015] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) establishes latency in resting memory CD4+ T cells and cells of myeloid lineage. In contrast to the T cells, cells of myeloid lineage are resistant to the HIV-1 induced cytopathic effect. Cells of myeloid lineage including macrophages are present in anatomical sanctuaries making them a difficult drug target. In addition, the long life span of macrophages as compared to the CD4+ T cells make them important viral reservoirs in infected individuals especially in the late stage of viral infection where CD4+ T cells are largely depleted. In the past decade, HIV-1 persistence in resting CD4+ T cells has gained considerable attention. It is currently believed that rebound viremia following cessation of combination anti-retroviral therapy (cART) originates from this source. However, the clinical relevance of this reservoir has been questioned. It is suggested that the resting CD4+ T cells are only one source of residual viremia and other viral reservoirs such as tissue macrophages should be seriously considered. In the present review we will discuss how macrophages contribute to the development of long-lived latent reservoirs and how macrophages can be used as a therapeutic target in eradicating latent reservoir.
Collapse
|
7
|
Zanet DL, Thorne A, Singer J, Maan EJ, Sattha B, Le Campion A, Soudeyns H, Pick N, Murray M, Money DM, Côté HCF. Association between short leukocyte telomere length and HIV infection in a cohort study: No evidence of a relationship with antiretroviral therapy. Clin Infect Dis 2014; 58:1322-32. [PMID: 24457340 DOI: 10.1093/cid/ciu051] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Individuals infected with human immunodeficiency virus (HIV) appear to age faster than the general population, possibly related to HIV infection, antiretroviral therapy, and/or social/environmental factors. We evaluated leukocyte telomere length (LTL), a marker of cellular aging, in HIV-infected and uninfected adults. METHODS Clinical data and blood were collected from Children and women: AntiRetrovirals and the Mechanism of Aging (CARMA) cohort study participants. Variables found to be important in univariate analysis were multivariate model candidates. RESULTS Of the 229 HIV-infected and 166 HIV-uninfected participants, 76% were women, and 71% were current/previous smokers. In a multivariate model of all participants, older age (P < .001), HIV infection (P = .04), active hepatitis C virus (HCV) infection (P = .02), and smoking (P < .003) were associated with shorter LTL. An interaction was detected, whereby smoking was associated with shorter LTL in HIV-uninfected subjects only. Among those, age and smoking (P ≤ .01) were related to shorter LTL. In 2 models of HIV-infected individuals, age (P ≤ .002) and either active HCV infection (P = .05) or peak HIV RNA ≥100 000 copies/mL (P = .04) were associated with shorter LTL, whereas other HIV disease or treatment parameters were unrelated. CONCLUSIONS Our results suggest that acquisition of HIV and viral load are primarily responsible for the association between HIV-positive status and shorter LTL. The lack of association between LTL and time since HIV diagnosis, antiretroviral treatment, or degree of immune suppression would implicate HIV infection-related factors rather than disease progression or treatment. Smoking effects on LTL appear masked by HIV, and HCV infection may accelerate LTL shortening, particularly in coinfected individuals. The effect of early therapeutic intervention on LTL in HIV and HCV infections should be evaluated.
Collapse
Affiliation(s)
- DeAnna L Zanet
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ojeda D, López-Costa JJ, Sede M, López EM, Berria MI, Quarleri J. Increased in vitro glial fibrillary acidic protein expression, telomerase activity, and telomere length after productive human immunodeficiency virus-1 infection in murine astrocytes. J Neurosci Res 2013; 92:267-74. [PMID: 24254728 DOI: 10.1002/jnr.23294] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 12/17/2022]
Abstract
Although HIV-associated neurocognitive disorders (HAND) result from injury and loss of neurons, productive infection routinely takes place in cells of macrophage lineage. In such a complex context, astrocytosis induced by local chemokines/cytokines is one of the hallmarks of HIV neuropathology. Whether this sustained astrocyte activation is able to alter telomere-aging process is unknown. We hypothesized that interaction of HIV with astrocytes may impact astrocyte telomerase activity (TA) and telomere length in a scenario of astrocytic activation measured by expression of glial fibrillary acidic protein (GFAP). To test this hypothesis, cultured murine astrocytes were challenged with pseudotyped HIV/vesicular stomatitis virus (HIV/VSV) to circumvent the absence of viral receptors; and GFAP, telomerase activity, and telomere length were quantified. As an early and transient event after HIV infection, both TA activity and telomere length were significantly augmented (P < 0.001). Later, a strong negative correlation (-0.8616, P < 0.0001) between virus production and telomerase activity was demonstrated. Once HIV production had reached a peak (7 dpi), the TA decreased, showing levels similar to those of noninfected cells. In contrast, the astrocyte became activated, exhibiting significantly increased levels of GFAP expression directly related to the level of HIV/VSV replication (P < 0.0001). Our results suggest that HIV-infected astrocytes exhibit early disturbance in their cellular functions, such as telomerase activity and telomere length, that may attenuate cell proliferation and enhance the astrocyte dysregulation, contributing to HIV neuropathogenesis. Understanding the mechanisms involved in HIV-mediated persistence by altering the telomere-related aging processes could aid in the development of therapeutic modalities for neurological complications of HIV infection.
Collapse
Affiliation(s)
- Diego Ojeda
- Instituto de Investigaciones Biomédicas en Retrovirus y Sida, Universidad de Buenos Aires-CONICET, Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
9
|
Comandini A, Naro C, Adamo R, Akbar AN, Lanna A, Bonmassar E, Franzese O. Molecular mechanisms involved in HIV-1-Tat mediated inhibition of telomerase activity in human CD4+ T lymphocytes. Mol Immunol 2013; 54:181-92. [DOI: 10.1016/j.molimm.2012.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/29/2012] [Accepted: 12/04/2012] [Indexed: 12/16/2022]
|
10
|
Wang X, Singh S, Jung HY, Yang G, Jun S, Sastry KJ, Park JI. HIV-1 Vpr protein inhibits telomerase activity via the EDD-DDB1-VPRBP E3 ligase complex. J Biol Chem 2013; 288:15474-80. [PMID: 23612978 PMCID: PMC3668709 DOI: 10.1074/jbc.m112.416735] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 04/22/2013] [Indexed: 11/06/2022] Open
Abstract
Viral pathogens utilize host cell machinery for their benefits. Herein, we identify that HIV-1 Vpr (viral protein R) negatively modulates telomerase activity. Telomerase enables stem and cancer cells to evade cell senescence by adding telomeric sequences to the ends of chromosomes. We found that Vpr inhibited telomerase activity by down-regulating TERT protein, a catalytic subunit of telomerase. As a molecular adaptor, Vpr enhanced the interaction between TERT and the VPRBP substrate receptor of the DYRK2-associated EDD-DDB1-VPRBP E3 ligase complex, resulting in increased ubiquitination of TERT. In contrast, the Vpr mutant identified in HIV-1-infected long-term nonprogressors failed to promote TERT destabilization. Our results suggest that Vpr inhibits telomerase activity by hijacking the host E3 ligase complex, and we propose the novel molecular mechanism of telomerase deregulation in possibly HIV-1 pathogenesis.
Collapse
Affiliation(s)
- Xin Wang
- From the Departments of Experimental Radiation Oncology and
| | | | - Hae-Yun Jung
- From the Departments of Experimental Radiation Oncology and
| | | | - Sohee Jun
- From the Departments of Experimental Radiation Oncology and
| | | | - Jae-Il Park
- From the Departments of Experimental Radiation Oncology and
- the Program in Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and
- the Graduate School of Biomedical Sciences at Houston, The University of Texas Health Science Center and MD Anderson Cancer Center, Houston, Texas 77030
| |
Collapse
|
11
|
HIV-1 induces telomerase activity in monocyte-derived macrophages, possibly safeguarding one of its reservoirs. J Virol 2012; 86:10327-37. [PMID: 22787205 DOI: 10.1128/jvi.01495-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Monocyte-derived macrophages (MDM) are widely distributed in all tissues and organs, including the central nervous system, where they represent the main part of HIV-infected cells. In contrast to activated CD4(+) T lymphocytes, MDM are resistant to cytopathic effects and survive HIV infection for a long period of time. The molecular mechanisms of how HIV is able to persist in macrophages are not fully elucidated yet. In this context, we have studied the effect of in vitro HIV-1 infection on telomerase activity (TA), telomere length, and DNA damage. Infection resulted in a significant induction of TA. This increase was directly proportional to the efficacy of HIV infection and was found in both nuclear and cytoplasmic extracts, while neither UV light-inactivated HIV nor exogenous addition of the viral protein Tat or gp120 affected TA. Furthermore, TA was not modified during monocyte-macrophage differentiation, MDM activation, or infection with vaccinia virus. HIV infection did not affect telomere length. However, HIV-infected MDM showed less DNA damage after oxidative stress than noninfected MDM, and this resistance was also increased by overexpressing telomerase alone. Taken together, our results suggest that HIV induces TA in MDM and that this induction might contribute to cellular protection against oxidative stress, which could be considered a viral strategy to make macrophages better suited as longer-lived, more resistant viral reservoirs. In the light of the clinical development of telomerase inhibitors as anticancer therapeutics, inhibition of TA in HIV-infected macrophages might also represent a novel therapeutic target against viral reservoirs.
Collapse
|
12
|
Barsov EV. Telomerase and primary T cells: biology and immortalization for adoptive immunotherapy. Immunotherapy 2012; 3:407-21. [PMID: 21395382 DOI: 10.2217/imt.10.107] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Telomeres are specialized repeats, present at the end of chromosomes, whose loss during cell division is followed by growth arrest, a central mechanism of replicative senescence in human cells. Telomere length in stem cells is maintained by telomerase, a specialized reverse transcriptase, whose function is to restore shortening telomeres. Unlike most somatic cell types, human T lymphocytes are capable of briefly reactivating telomerase expression at the time of stimulation. Telomerase expression in T lymphocytes is modulated by a variety of external stimuli and by viral infections. However, telomerase reactivation in stimulated, proliferating human T lymphocytes is limited and cannot prevent the ultimate onset of senescence. Ectopic telomerase expression can rescue human and macaque antigen-specific T cells from senescence. Primary T cells have been engineered with telomerase to have substantially extended replicative lifespans without the loss of primary cell functions or malignant transformation. 'Immortal' antigen-specific T-cell lines and clones overexpressing telomerase are an invaluable source of well-characterized quasi-primary T cells for research of T-cell biology and are potentially useful for immunotherapy of cancer and AIDS.
Collapse
Affiliation(s)
- Eugene V Barsov
- SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, MD 21702, USA.
| |
Collapse
|
13
|
Interferon alpha on expression of hTERT mRNA in peripheral blood mononuclear cells of patients with chronic hepatitis B. Clin Dev Immunol 2011; 2011:920146. [PMID: 21647411 PMCID: PMC3102520 DOI: 10.1155/2011/920146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 02/07/2011] [Accepted: 03/14/2011] [Indexed: 11/17/2022]
Abstract
Cell division is closely related to telomerase activity (hTERT mRNA). Lower expression of lymphocitic hTERT mRNA may easily cause cell aging, which is not beneficial to maintaining a durable lymphocyte division. To date, there is no study to investigate IFNα therapy on hTERT mRNA expression in PBMCs of patients with chronic hepatitis B (CHB). We quantitatively detected hTERT mRNA from study subjects and made each hTERT mRNA normalized (NhTERT mRNA). Mean NhTERT mRNA level was lower in either CHB group, but it significantly increased in IFNα-treated group compared with CHB control group, and a longer duration of IFNα therapy could increase the level. Moreover, the mean NhTERT mRNA in subgroup with HBeAg loss was significantly higher than that in subgroup without. NhTERT mRNA was markedly correlated with CD3+ T lymphocyte count and CD4+/CD8+ ratio. The results showed that IFNα therapy could upregulate the expression of hTERT mRNA in PBMCs.
Collapse
|
14
|
Tichon A, Gowda BK, Slavin S, Gazit A, Priel E. Telomerase activity and expression in adult human mesenchymal stem cells derived from amyotrophic lateral sclerosis individuals. Cytotherapy 2009; 11:837-48. [DOI: 10.3109/14653240903136979] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
15
|
Onlamoon N, Plagman N, Rogers KA, Mayne AE, Bostik P, Pattanapanyasat K, Ansari AA, Villinger F. Anti-CD3/28 mediated expansion of macaque CD4+ T cells is polyclonal and provides extended survival after adoptive transfer. J Med Primatol 2007; 36:206-18. [PMID: 17669209 DOI: 10.1111/j.1600-0684.2007.00238.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Our lab has previously shown that adoptive transfer of in vitro expanded autologous purified polyclonal CD4(+) T cells using anti-CD3/CD28 coated beads induced antiviral responses capable of controlling simian immunodeficiency virus (SIV) replication in vivo. RESULTS Expansion on anti-CD3/28 coated beads was found to induce a true polyclonal expansion as CFSE labeled cells uniformly showed dilution of the dye over several days of culture, in contrast to aliquots of the same cells subjected to mitogen stimulation. Of interest was the finding that CD4(+) T cells collected before and during early chronic SIV infection or AIDS stage did not show any or only modest differences in proliferative response or expansion kinetics. The reason for such excellent expansion properties was analyzed by the quantitation of telomerase activity in aliquots of expanding CD4(+) T cells from sample collected at various times post-infection. First, anti-CD3/28 expanded CD4(+) T cells exhibited telomerase levels 2- to 20-fold higher than the starting population of CD4(+) T cells. Moreover, while telomerase activity in ex vivo tested CD4(+) T cells was found to decrease following SIV infection and disease progression, anti-CD3/28 expansion appeared to restore significant levels of telomerase activity as no difference was noted in telomerase expression between CD4(+) T cells expanded from samples collected before or during the chronic SIV infection. When such expanded and CFSE labeled T cells were autologously transferred to monkeys, evidence for extended survival in vivo was provided as CFSE labeled cells were detected to relatively high levels in blood and spleen at 1 week post-infection. CONCLUSION In summary, the data suggest that anti-CD3/28 mediated expansion of CD4(+) T cells retains its immunotherapeutic potential not only during the early stages of lentiviral infection but also at more advanced stages of disease.
Collapse
Affiliation(s)
- Nattawat Onlamoon
- Department of Pathology & Lab Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | | | | | | | | | |
Collapse
|