1
|
Stunnenberg M, van Hamme JL, Trimp M, Gringhuis SI, Geijtenbeek TB. Abortive HIV-1 RNA induces pro-IL-1β maturation via protein kinase PKR and inflammasome activation in humans. Eur J Immunol 2021; 51:2464-2477. [PMID: 34223639 PMCID: PMC8518791 DOI: 10.1002/eji.202149275] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/28/2021] [Accepted: 07/02/2021] [Indexed: 12/12/2022]
Abstract
The proinflammatory cytokine IL-1β mediates high levels of immune activation observed during acute and chronic human immunodeficiency virus 1 (HIV-1) infection. Little is known about the mechanisms that drive IL-1β activation during HIV-1 infection. Here, we have identified a crucial role for abortive HIV-1 RNAs in inducing IL-1β in humans. Abortive HIV-1 RNAs were sensed by protein kinase RNA-activated (PKR), which triggered activation of the canonical NLRP3 inflammasome and caspase-1, leading to pro-IL-1β processing and secretion. PKR activated the inflammasome via ROS generation and MAP kinases ERK1/2, JNK, and p38. Inhibition of PKR during HIV-1 infection blocked IL-1β production. As abortive HIV-1 RNAs are produced during productive infection and latency, our data strongly suggest that targeting PKR signaling might attenuate immune activation during acute and chronic HIV-1 infection.
Collapse
Affiliation(s)
- Melissa Stunnenberg
- Amsterdam UMCDepartment of Experimental ImmunologyUniversity of AmsterdamAmsterdam Institute for Infection & ImmunityAmsterdamThe Netherlands
| | - John L. van Hamme
- Amsterdam UMCDepartment of Experimental ImmunologyUniversity of AmsterdamAmsterdam Institute for Infection & ImmunityAmsterdamThe Netherlands
| | - Marjolein Trimp
- Amsterdam UMCDepartment of Experimental ImmunologyUniversity of AmsterdamAmsterdam Institute for Infection & ImmunityAmsterdamThe Netherlands
| | - Sonja I. Gringhuis
- Amsterdam UMCDepartment of Experimental ImmunologyUniversity of AmsterdamAmsterdam Institute for Infection & ImmunityAmsterdamThe Netherlands
| | - Teunis B.H. Geijtenbeek
- Amsterdam UMCDepartment of Experimental ImmunologyUniversity of AmsterdamAmsterdam Institute for Infection & ImmunityAmsterdamThe Netherlands
| |
Collapse
|
2
|
Goonetilleke N, Clutton G, Swanstrom R, Joseph SB. Blocking Formation of the Stable HIV Reservoir: A New Perspective for HIV-1 Cure. Front Immunol 2019; 10:1966. [PMID: 31507594 PMCID: PMC6714000 DOI: 10.3389/fimmu.2019.01966] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/05/2019] [Indexed: 12/13/2022] Open
Abstract
Recent studies demonstrate that the stable HIV-1 reservoir in resting CD4+ T cells is mostly formed from viruses circulating when combination antiretroviral therapy (ART) is initiated. Here we explore the immunological basis for these observations. Untreated HIV-1 infection is characterized by a progressive depletion of memory CD4+ T cells which mostly express CD127, the α chain of the IL-7 receptor (IL-7R). Depletion results from both direct infection and bystander loss of memory CD4+ T cells in part attributed to dysregulated IL-7/IL-7R signaling. While IL-7/IL7R signaling is not essential for the generation of effector CD4+ T cells from naïve cells, it is essential for the further transition of effectors to memory CD4+ T cells and their subsequent homeostatic maintenance. HIV-1 infection therefore limits the transition of CD4+ T cells from an effector to long-lived memory state. With the onset of ART, virus load (VL) levels rapidly decrease and the frequency of CD127+ CD4+ memory T cells increases, indicating restoration of effector to memory transition in CD4+ T cells. Collectively these data suggest that following ART initiation, HIV-1 infected effector CD4+ T cells transition to long-lived, CD127+ CD4+ T cells forming the majority of the stable HIV-1 reservoir. We propose that combining ART initiation with inhibition of IL-7/IL-7R signaling to block CD4+ T cell memory formation will limit the generation of long-lived HIV-infected CD4+ T cells and reduce the overall size of the stable HIV-1 reservoir.
Collapse
Affiliation(s)
- Nilu Goonetilleke
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC HIV-1 Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Genevieve Clutton
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC HIV-1 Cure Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ron Swanstrom
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sarah B. Joseph
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| |
Collapse
|
3
|
de Armas LR, Pallikkuth S, George V, Rinaldi S, Pahwa R, Arheart KL, Pahwa S. Reevaluation of immune activation in the era of cART and an aging HIV-infected population. JCI Insight 2017; 2:e95726. [PMID: 29046481 PMCID: PMC5846952 DOI: 10.1172/jci.insight.95726] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/20/2017] [Indexed: 09/16/2023] Open
Abstract
Biological aging is associated with immune activation (IA) and declining immunity due to systemic inflammation. It is widely accepted that HIV infection causes persistent IA and premature immune senescence despite effective antiretroviral therapy and virologic suppression; however, the effects of combined HIV infection and aging are not well defined. Here, we assessed the relationship between markers of IA and inflammation during biological aging in HIV-infected and -uninfected populations. Antibody response to seasonal influenza vaccination was implemented as a measure of immune competence and relationships between IA, inflammation, and antibody responses were explored using statistical modeling appropriate for integrating high-dimensional data sets. Our results show that markers of IA, such as coexpression of HLA antigen D related (HLA-DR) and CD38 on CD4+ T cells, exhibit strong associations with HIV infection but not with biological age. Certain variables that showed a strong relationship with aging, such as declining naive and CD38+ CD4 and CD8+ T cells, did so regardless of HIV infection. Interestingly, the variable of biological age was not identified in a predictive model as significantly impacting vaccine responses in either group, while distinct IA and inflammatory variables were closely associated with vaccine response in HIV-infected and -uninfected populations. These findings shed light on the most relevant and persistent immune defects during virological suppression with antiretroviral therapy.
Collapse
Affiliation(s)
| | | | | | | | | | - Kristopher L. Arheart
- Department of Epidemiology and Public Health, Division of Biostatistics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | | |
Collapse
|
4
|
Garg H, Joshi A. Host and Viral Factors in HIV-Mediated Bystander Apoptosis. Viruses 2017; 9:v9080237. [PMID: 28829402 PMCID: PMC5579491 DOI: 10.3390/v9080237] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 02/07/2023] Open
Abstract
Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis.
Collapse
Affiliation(s)
- Himanshu Garg
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
| | - Anjali Joshi
- Center of Emphasis in Infectious Diseases, Department of Biomedical Sciences, Texas Tech University Health Sciences Center, 5001 El Paso Dr., El Paso, TX 79905, USA.
| |
Collapse
|
5
|
Rainwater-Lovett K, Nkamba HC, Mubiana-Mbewe M, Moore CB, Moss WJ. Immunologic risk factors for early mortality after starting antiretroviral therapy in HIV-infected Zambian children. AIDS Res Hum Retroviruses 2013; 29:479-87. [PMID: 23025633 DOI: 10.1089/aid.2012.0246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To explore immunologic risk factors for death within 90 days of highly active antiretroviral therapy (HAART) initiation, CD4(+) and CD8(+) T cell subsets were measured by flow cytometry and characterized by logistic regression in 149 Zambian children between 9 months and 10 years of age enrolled in a prospective, observational study of the impact of HAART on measles immunity. Of 21 children who died during follow-up, 17 (81%) had known dates of death and 16 (76%) died within 90 days of initiating HAART. Young age and low weight-for-age z-scores were associated with increased risks of mortality within 90 days of starting HAART, whereas CD4(+) T cell percentage was not associated with mortality. After adjusting for these factors, each 10% increase in CD8(+) effector T cells increased the odds of overall mortality [OR=1.43 (95% CI: 1.08, 1.90)] and was marginally associated with early mortality [OR=1.29 (95% CI: 0.97, 1.72)]. Conversely, each 10% increase in CD4(+) central memory T cells decreased the odds of overall [OR=0.06 (95% CI: 0.01, 0.59)] and early mortality [OR=0.09 (95% CI: 0.01, 0.97)]. Logistic regression prediction models demonstrated areas under the receiver-operator characteristic curves of ≥85% for early and overall mortality, with bootstrapped sensitivities of 82-85% upon validation, supporting the predictive accuracy of the models. CD4(+) and CD8(+) T cell subsets may be more accurate predictors of early mortality than CD4(+) T cell percentages and could be used to identify children who would benefit from more frequent clinical monitoring after initiating HAART.
Collapse
Affiliation(s)
- Kaitlin Rainwater-Lovett
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Hope C. Nkamba
- Virology Laboratory, University Teaching Hospital, Lusaka, Zambia
| | | | - Carolyn Bolton Moore
- Center for Infectious Disease Research-Zambia, Lusaka, Zambia
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J. Moss
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| |
Collapse
|
6
|
Avelino-Silva VI, Ho YL, Avelino-Silva TJ, Santos SDS. Aging and HIV infection. Ageing Res Rev 2011; 10:163-72. [PMID: 20974294 DOI: 10.1016/j.arr.2010.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 10/12/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Population aging has become a global phenomenon, and HIV infection among older individuals is also increasing. Because age can affect the progression of HIV infection, we aimed to evaluate the present knowledge on HIV infection in older patients. METHODS Literature review of the last 20 years. RESULTS Older HIV-infected patients have lower CD4(+) T cell counts, higher viral load and are more frequently symptomatic at diagnosis. The infection progresses more rapidly, with higher morbidity and lethality rates. However, older patients are more compliant to antiretroviral treatment; they experience a better virologic response, and treatment represents a positive clinical impact. Aging affects the complex interaction between HIV infection and the immune system. Both conditions contribute to the dysfunction of immune cells, including a decrease in the phagocytes' microbicidal capability, natural killer cells' cytolytic function, expression of toll-like receptors and production of interleukin-12. Chronic immune activation responsible for the depletion of CD4(+) and CD8(+) T cells in HIV infection appears to worsen with senescence. Older patients also exhibit a less robust humoral response, with the production of less avid and specific antibodies. CONCLUSION Both HIV and aging contribute to immune dysfunction, morbidity and mortality. However, highly active antiretroviral therapy (HAART) is beneficial for older patients, and treatment of older patients should not be discouraged.
Collapse
|
7
|
Miró JM, Manzardo C, Pich J, Domingo P, Ferrer E, Arribas JR, Ribera E, Arrizabalaga J, Loncá M, Cruceta A, de Lazzari E, Fuster M, Podzamczer D, Plana M, Gatell JM. Immune reconstitution in severely immunosuppressed antiretroviral-naive HIV type 1-infected patients using a nonnucleoside reverse transcriptase inhibitor-based or a boosted protease inhibitor-based antiretroviral regimen: three-year results (The Advanz Trial): a randomized, controlled trial. AIDS Res Hum Retroviruses 2010; 26:747-57. [PMID: 20624069 DOI: 10.1089/aid.2009.0105] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Late diagnosis of HIV-1 infection is quite frequent in Western countries. Very few randomized clinical trials to determine the best antiretroviral treatment in patients with advanced HIV-1 infection have been performed. To compare immune reconstitution in two groups of very immunosuppressed (less than 100 CD4(+) cells/microl), antiretroviral-naive HIV-1-infected adults, 65 patients were randomly assigned in a 1:1 ratio to receive zidovudine + lamivudine + efavirenz (group A, 34 patients) or zidovudine + lamivudine + ritonavir-boosted indinavir (group B, 31 patients). The median (interquartile range) CD4(+) cell increase after 12 and 36 months was +199 (101, 258) and +299 (170, 464) cells/microl in the efavirenz arm and +136 (57, 235) and +228 (119, 465) cells/microl in the ritonavir-boosted indinavir arm (p > 0.05 for all time points). The proportion (95% confidence interval) of patients achieving HIV-1 RNA levels under 50 copies/ml was significantly greater in the efavirenz arm at 3 years by the intention-to-treat analysis [59% (41%, 75%) vs. 23% (10%, 41%)], whereas no differences were found in the on-treatment analysis. Immune activation (CD8(+)CD38(+) and CD8(+)CD38DR(+) T cells) was significantly lower for the efavirenz arm from month 6 to month 24. Adverse events were more frequent in the ritonavir-boosted indinavir arm. Almost all cases of disease progression and death were observed in the first year of treatment, with no significant differences between the two arms (p = 0.79 by the log-rank test). At 1 and 3 years, the immune reconstitution induced by an efavirenz-based regimen in very immunosuppressed patients was at least as potent as that induced by a ritonavir-boosted protease inhibitor-based antiretroviral regimen.
Collapse
Affiliation(s)
- José M. Miró
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | | | - Judith Pich
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | | | - Elena Ferrer
- Hospital Bellvitge-IDIBELL, University of Barcelona, Barcelona, Spain
| | | | | | | | - Montserrat Loncá
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Anna Cruceta
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Elisa de Lazzari
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | | | - Daniel Podzamczer
- Hospital Bellvitge-IDIBELL, University of Barcelona, Barcelona, Spain
| | - Montserrat Plana
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - José M. Gatell
- Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | | |
Collapse
|
8
|
Bosinger SE, Li Q, Gordon SN, Klatt NR, Duan L, Xu L, Francella N, Sidahmed A, Smith AJ, Cramer EM, Zeng M, Masopust D, Carlis JV, Ran L, Vanderford TH, Paiardini M, Isett RB, Baldwin DA, Else JG, Staprans SI, Silvestri G, Haase AT, Kelvin DJ. Global genomic analysis reveals rapid control of a robust innate response in SIV-infected sooty mangabeys. J Clin Invest 2010; 119:3556-72. [PMID: 19959874 DOI: 10.1172/jci40115] [Citation(s) in RCA: 259] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/19/2009] [Indexed: 01/07/2023] Open
Abstract
Natural SIV infection of sooty mangabeys (SMs) is nonprogressive despite chronic virus replication. Strikingly, it is characterized by low levels of immune activation, while pathogenic SIV infection of rhesus macaques (RMs) is associated with chronic immune activation. To elucidate the mechanisms underlying this intriguing phenotype, we used high-density oligonucleotide microarrays to longitudinally assess host gene expression in SIV-infected SMs and RMs. We found that acute SIV infection of SMs was consistently associated with a robust innate immune response, including widespread upregulation of IFN-stimulated genes (ISGs) in blood and lymph nodes. While SMs exhibited a rapid resolution of ISG expression and immune activation, both responses were observed chronically in RMs. Systems biology analysis indicated that expression of the lymphocyte inhibitory receptor LAG3, a marker of T cell exhaustion, correlated with immune activation in SIV-infected RMs but not SMs. Our findings suggest that active immune regulatory mechanisms, rather than intrinsically attenuated innate immune responses, underlie the low levels of immune activation characteristic of SMs chronically infected with SIV.
Collapse
Affiliation(s)
- Steven E Bosinger
- Department of Pathology and Laboratory Medicine, and Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Tuaillon E, Al Tabaa Y, Baillat V, Segondy M, Picot MC, Reynes J, Vendrell JP. Close association of CD8+/CD38 bright with HIV-1 replication and complex relationship with CD4+ T-cell count. CYTOMETRY PART B-CLINICAL CYTOMETRY 2009; 76:249-60. [PMID: 19072838 DOI: 10.1002/cyto.b.20467] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Measuring lymphocyte activation provides information in addition to CD4(+) T-cell count for immune monitoring of HIV-1 infected patients. CD38 is a well-established activation marker that is generally analyzed on the whole population of CD8(+) T-cells. Focusing specifically on CD38 high expression (CD8(+)/CD38(bright)) may be an interesting surrogate gating strategy because CD38(bright) characterizes principally activated memory cells. METHODS CD8(+)/CD38(bright) was investigated in 1,353 HIV-1 infected patients over a one-year period to establish relevant cutoff values and clarify the relationships of this marker with HIV-1 RNA viral load (VL) and CD4(+) T-cell count. RESULTS The CD8(+)/CD38(bright) (>8,500 CD38 binding site per cells) is well correlated with HIV-1 VL (r = 0.87, P < 0.001) in this longitudinal follow-up of nonimmunodepressed patients that initiated antiviral therapy (ART). In aviremic patients on ART, the marker was highly predictive of VL rebound (sensitivity 93%, specificity 64% for a VL level of detection >200 copies/ml). While the CD8(+)/CD38(bright) moderately correlated with CD4(+) T-cell count independently of the VL (r = -0.37, P < 0.001), it increased dramatically in aviremic patient groups that exhibited profound CD4(+) T-cell depletion (median 39% for CD4(+) T-cell counts <50/mm(3)). This result indicates that other additional immunological and/or viral factors than readily detectable HIV-1 replication appears to be involved in T-cell activation of immunodepressed individuals. CONCLUSIONS CD8(+)/CD38(bright) is an effective marker for monitoring T-cell activation, which is a central factor of HIV-1 pathogenesis. This gating strategy requires only a single additional staining in conventional four color CD4 protocols.
Collapse
Affiliation(s)
- Edouard Tuaillon
- Laboratoire de Virologie, Centre Hospitalier Universitaire de Montpellier, France
| | | | | | | | | | | | | |
Collapse
|
10
|
Loss of CD127 expression links immune activation and CD4(+) T cell loss in HIV infection. Trends Microbiol 2008; 16:567-73. [PMID: 18964017 DOI: 10.1016/j.tim.2008.08.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 08/05/2008] [Accepted: 08/18/2008] [Indexed: 02/08/2023]
Abstract
Although chronic immune activation correlates with CD4(+) T cell loss in HIV infection, an understanding of the factors mediating T cell depletion remains incomplete. We propose that reduced expression of CD127 (IL-7 receptor alpha chain, IL-7Ralpha), induced by immune activation, contributes to CD4(+) T cell loss in HIV infection. In particular, loss of CD127 on central memory CD4(+) T cells (T(CM)) severely restrains the regenerative capacity of the memory component of the immune system, resulting in a limited ability to control T cell homeostasis. Studies from both pathogenic and controlled HIV infection indicate that the containment of immune activation and preservation of CD127 expression are critical to the stability of CD4(+) T cells in infection. A better understanding of the factors regulating CD127 expression in HIV disease, particularly on T(CM) cells, might unveil new approaches exploiting the IL-7/IL-7R receptor pathway to restore T cell homeostasis and promote immune reconstitution in HIV infection.
Collapse
|
11
|
Has HIV evolved to induce immune pathogenesis? Trends Immunol 2008; 29:322-8. [PMID: 18524680 DOI: 10.1016/j.it.2008.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 04/07/2008] [Accepted: 04/14/2008] [Indexed: 01/10/2023]
Abstract
Human immunodeficiency virus (HIV) induces a chronic generalized activation of the immune system, which plays an important role in the pathogenesis of AIDS. This ability of the virus might either be an evolved (adaptive) trait or a coincidental side effect of jumping to a new host species. We argue that selection favours the ability of HIV to induce immune activation at the local sites of infection (e.g. lymph follicles) but not at the systemic level. Immune activation increases the supply of susceptible target cells; however, mutations that increase systemic immune activation benefit all virus variants equally and are therefore selectively neutral. We thus conclude that the generalized immune activation that is probably responsible for pathogenesis is probably not directly under selection.
Collapse
|
12
|
Koesters SA, Alimonti JB, Wachihi C, Matu L, Anzala O, Kimani J, Embree JE, Plummer FA, Fowke KR. IL-7Ralpha expression on CD4+ T lymphocytes decreases with HIV disease progression and inversely correlates with immune activation. Eur J Immunol 2006; 36:336-44. [PMID: 16421946 DOI: 10.1002/eji.200535111] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Many factors can influence the rate of HIV disease progression, including those that maintain T cell homeostasis. One key homeostatic regulator is the IL-7 receptor (IL-7R). Previous studies have shown IL-7R expression levels decrease in HIV infection, but effects on memory subtypes, CD4(+) T cells, and cell function have not been explored. The present study examined the expression of the IL-7Ralpha chain on naïve and memory T lymphocyte subsets of both HIV-positive and HIV-negative individuals from Nairobi, Kenya to assess the role of IL-7Ralpha in HIV disease. Expression of IL-7Ralpha was significantly reduced in all CD4(+) and CD8(+) T cell subsets in HIV-positive individuals. This reduction was further enhanced in those with advanced HIV progression. Expression of IL-7Ralpha was inversely correlated to immune activation, and apoptosis, and was positively correlated with CD4 count in both bivariate and multivariate analysis. Expression of IL-7Ralpha did not correlate with HIV viral loads, indicating the elevated immune activation seen in HIV-infected individuals may be impacting expression of IL-7Ralpha, independent of viral loads. Signaling via the IL-7R is essential for T cell homeostasis and maintenance of T cell memory. Reduction of this receptor may contribute to the homeostatic disruption seen in HIV.
Collapse
Affiliation(s)
- Sandra A Koesters
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada, R3E 0 W3
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Ayash-Rashkovsky M, Bentwich Z, Borkow G. TLR9 expression is related to immune activation but is impaired in individuals with chronic immune activation. Int J Biochem Cell Biol 2005; 37:2380-94. [PMID: 16024265 DOI: 10.1016/j.biocel.2005.05.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2005] [Revised: 04/27/2005] [Accepted: 05/31/2005] [Indexed: 11/15/2022]
Abstract
Millions of individuals in developing countries are infected with helminths and other chronic infectious diseases, such as HIV-1, which lead to persistent immune activation and unbalanced immune state. We have suggested that the capacity of chronically immune activated individuals to protect themselves, cope with infections, and mount protective immunity following vaccination, is highly impaired. Here we examined the expression of toll-like receptor 9 (TLR9), as an essential component in the recognition of immunostimulating bacterial CpG-DNA motifs, in different subsets of human peripheral blood mononuclear cells (PBMC) obtained from chronically immune activated and non-activated individuals. TLR9 expression was correlated to immune cell activation and was upregulated following phytohemagglutinin or anti-CD3 activation. PBMC obtained from chronically immune activated individuals had a different overall pattern of TLR9 expression, including reduced upregulation of this receptor following additional immune activation, and diminished responsiveness to CpG-DNA stimulation, in comparison to non-activated individuals. These differences may partly account for the reduced capacity of chronically immune activated individuals to mount effective immune responses and strengthen the notion that the host immune background should be considered in the design and trial of potential adjuvants and vaccines.
Collapse
Affiliation(s)
- Mila Ayash-Rashkovsky
- Ruth Ben-Ari Institute of Clinical Immunology, Kaplan Medical Center, Hebrew University Hadassah Medical School, Rehovot 76100, Israel.
| | | | | |
Collapse
|
14
|
Silvestri G. Naturally SIV-infected sooty mangabeys: are we closer to understanding why they do not develop AIDS? J Med Primatol 2005; 34:243-52. [PMID: 16128919 DOI: 10.1111/j.1600-0684.2005.00122.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Simian immunodeficiency viruses (SIV) infection of sooty mangabey (SM) monkeys (Cercocebus atys), a natural host species, does not induce CD4+ T cell depletion and acquired immunodeficiency syndrome (AIDS) despite chronic high levels of virus replication. In contrast, SIV infection of non-natural host species, such as rhesus macaques (RM), induces a disease that closely resembles AIDS in humans. The mechanisms underlying the lack of disease progression in SIV-infected SMs are incompletely understood, but certainly reflect a complex evolutionary adaptation whereby the host immune system is not significantly damaged by the highly replicating virus. It is now widely recognized that a better understanding of these mechanisms may provide clues to the pathogenesis of immunodeficiency in HIV-infected humans. In this article I discuss five different hypotheses that may account for the non-pathogenic course of infection in SIV-infected SMs and briefly review the available data supporting each of these hypotheses.
Collapse
Affiliation(s)
- Guido Silvestri
- Department of Medicine and Microbiology and Immunology; Emory Vaccine Center, Emory University School of Medicine; Atlanta, GA 30329, USA.
| |
Collapse
|
15
|
Shang H, Zhang Z, Jiang Y, Han X, Wang Y, Zhang M, Ye X, Liu Y, Diao Y, Dai D, Geng W. Activation and Coreceptor Expression of T Lymphocytes in HIV/AIDS Patients of China. J Clin Immunol 2005; 25:68-72. [PMID: 15742159 DOI: 10.1007/s10875-005-0359-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2004] [Indexed: 10/25/2022]
Abstract
The objective of this paper was to investigate the activation and coreceptor CCR5, CXCR4 expression of T lymphocytes in HIV/AIDS patients of China, and to study their association with disease progression. Seventy-seven HIV/AIDS patients and thirteen normal controls were enrolled and three-color flow-cytometry was used to detect the activation marker HLA-DR, CD38 and the coreceptor CCR5, CXCR4 expression on T lymphocytes in whole blood samples taken from the patients and the controls. The HLA-DR, CD38 and CCR5 expression on CD4, CD8+ T cells in AIDS patients was higher than in asymptomatic HIV-1 infected patients and normal controls (p < 0.05); The activation and CCR5 expression on T lymphocytes significantly correlated with CD4+ T lymphocyte number and viral load. The activation on T lymphocytes and the expression of CCR5 on T lymphocytes in HIV/AIDS patients of China are significantly correlated with disease progression.
Collapse
Affiliation(s)
- Hong Shang
- AIDS Research Center, the First Affiliated Hospital, China Medical University, Shenyang, People's Republic of China.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Vahlenkamp TW, Bull ME, Dow JL, Collisson EW, Winslow BJ, Phadke AP, Tompkins WAF, Tompkins MB. B7+CTLA4+ T cells engage in T-T cell interactions that mediate apoptosis: a model for lentivirus-induced T cell depletion. Vet Immunol Immunopathol 2004; 98:203-14. [PMID: 15010229 DOI: 10.1016/j.vetimm.2003.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2003] [Revised: 12/09/2003] [Accepted: 12/09/2003] [Indexed: 01/08/2023]
Abstract
Apoptosis in lymph node (LN) T cells of feline immunodeficiency virus (FIV)-infected cats is associated with cells co-expressing B7.1 and B7.2 costimulatory molecules, and their ligand CTLA4. To study the possibility of B7.1/B7.2-CTLA4 mediated T-T interactions and the predicted induction of T cell apoptosis in vitro, costimulatory molecules were up-regulated on CD4+ and CD8+ T cells by mitogen stimulation. B7.1 expression on in vitro stimulated CD4+ and CD8+ cells increased within 24h; B7.2 and CTLA4 expression increased after 48-72 h. Apoptosis, as analyzed by terminal deoxynucleotidyl transferase (transferase nick end labeling, TUNEL)-based staining followed by three color flow cytometric analysis, correlated to the cells expressing B7 and/or CTLA4. Blocking experiments revealed that CD4+ and CD8+ T cell apoptosis could be significantly inhibited with anti-B7 antibodies. As FIV infection results in immune activation with a T cell phenotype similar to that of the in vitro activated T cells, the data support the hypothesis that the chronic expansion of B7+CTLA4+ LN T cells in infected cats allows for T-T cell interactions resulting in T cell depletion and eventually the development of AIDS.
Collapse
Affiliation(s)
- Thomas W Vahlenkamp
- Immunology Program, North Carolina State University, Raleigh, NC 27606, USA.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Locher CP, Fujimura S, Murthy KK, Brasky K, Leland M, Levy JA. Expression patterns of phenotypic markers on lymphocytes from human immunodeficiency virus type 2-infected baboons. AIDS Res Hum Retroviruses 2003; 19:31-40. [PMID: 12581514 DOI: 10.1089/08892220360473943] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The development of AIDS in HIV-1-infected humans is associated with profound changes in the expression patterns of lymphocyte phenotypic markers associated with increased immune activation and with decreased recall immune responses. In assessing these immunologic changes in an animal model, we characterized the expression patterns of immune activation markers on lymphocyte subsets during the acute, chronic, and end stages of HIV-2 infection in baboons. Using flow cytometry, we identified 21 human-specific monoclonal antibodies that were cross-reactive with baboon lymphocytes; however, expression of only 2 of these markers was altered significantly after HIV-2 infection. We found an increase in baboon class II antigen (as measured by anti-HLA-DR) in the CD4(+) T cell subset within 8 weeks of infection (p = 0.045). Moreover, after 1 year of infection, CD11b was downregulated on CD8(+) T lymphocytes (p = 0.027). This downregulation of CD11b was consistently observed in all of the groups of baboons that were chronically infected with three different HIV-2 isolates. In addition, we found substantial downregulation of the interleukin 2 receptor (CD25) and upregulation of class II antigen on CD8(+) lymphocytes in a baboon with an AIDS-like disease. These and other phenotypic markers of immune activation may facilitate characterization of the immunopathogenesis of AIDS in nonhuman primate animal models.
Collapse
Affiliation(s)
- Christopher P Locher
- Division of Hematology and Oncology, Department of Medicine, University of California, San Francisco 94143, USA
| | | | | | | | | | | |
Collapse
|
18
|
Almeida CAM, Price P, French MAH. Immune activation in patients infected with HIV type 1 and maintaining suppression of viral replication by highly active antiretroviral therapy. AIDS Res Hum Retroviruses 2002; 18:1351-5. [PMID: 12487806 DOI: 10.1089/088922202320935429] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Immune activation associated with HIV infection declines after highly active antiretroviral therapy (HAART), but may persist or recur in some patients. It is not clear whether this reflects a resurgence of HIV replication or another cause of immune activation, such as inflammatory reactions to opportunistic pathogens (immune restoration disease [IRD]). Here, we studied plasma and cellular immune activation markers in adult HIV-1 patients who had received HAART for >12 months and maintained plasma HIV RNA levels of <400 copies/ml for >6 months. Plasma interleukin 1 receptor antagonist and tumor necrosis factor receptor I levels were similar in patients and HIV-negative control subjects, but the highest levels occurred mainly in patients with a history of IRD. In contrast, expression of HLA-DR and CD38 on monocytes and of HLA-DR on CD8(+) T cells was higher in patients than in control subjects. Thus, cellular markers of immune activation are abnormal in some patients with a good virological response to HAART, and abnormalities of plasma immune activation markers correlate with a history of IRD.
Collapse
Affiliation(s)
- Coral-Ann M Almeida
- Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital, WA 6001, Australia
| | | | | |
Collapse
|
19
|
Leng Q, Bentwich Z, Magen E, Kalinkovich A, Borkow G. CTLA-4 upregulation during HIV infection: association with anergy and possible target for therapeutic intervention. AIDS 2002; 16:519-29. [PMID: 11872994 DOI: 10.1097/00002030-200203080-00002] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To study the role of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) during HIV infection. METHODS Intracellular CTLA-4 expression, determined by flow-cytometry, and proliferative responses to HIV antigens, were studied in peripheral blood mononuclear cells (PBMC) from 93 HIV-1-infected [HIV(+)] patients and 40 HIV-1 seronegative controls. RESULTS The proportions of CTLA-4 expressing CD4+ T cells were: (1) significantly higher in HIV(+) patients, 10.95 +/- 0.66%, than in controls, 6 +/- 0.45% (P < 0.0001); (2) inversely correlated to CD4+ counts (r = -0.67, P < 0.005, n = 16, drug-naive patients; r = -0.57, P < 0.0001, n = 77, HAART-treated patients); and (3) positively correlated to proportion of activated (HLA-DR+CD3+) (r = 0.53, P < 0.0001) and memory (CD45RO+CD4+) T cells (r = 0.46, P < 0.001). CD28 median fluorescence intensity in CTLA-4- cells was twice that in CTLA-4+ cells (140 +/- 5.3 versus 70 +/- 2.28, P < 0.00001), whereas cells low in CD28 and CD4, expressed more CTLA-4 (P < 0.0001). Higher proportion of CTLA-4+CD4+ cells expressed CCR5 and Ki-67, in comparison with CTLA-4-CD4+ cells, (65 +/- 11.9 and 25 +/- 7.5% versus 27 +/- 8.9 and 3.7 +/- 2%, P < 0.0001 and P < 0.01, respectively). Among HAART-treated patients, with viral load below detectable levels, CD4+ cells increase was inversely correlated to %CTLA-4+CD4+ cells (r = -0.5, P = 0.003, n = 39). Proliferation of PBMC to anti-CD3, gp-120 depleted HIV-1 antigen or HIV-1 p24 stimulation was inversely correlated with CTLA-4 levels (r = -0.68, P = 0.0035; r = -0.38,P = 0.04; and r = -0.43, P = 0.028, respectively). CONCLUSIONS (1) CTLA-4 is upregulated during HIV infection and may therefore account for CD4 T-cell decline and anergy in HIV-1 infection. (2) Increased levels of CTLA-4 may undermine immune responses and in the HAART-treated patient-immune reconstitution. (3) Blocking of CTLA-4 may offer a novel approach for immune-based therapy in HIV infection.
Collapse
Affiliation(s)
- Qibin Leng
- Ruth Ben-Ari Institute of Clinical Immunology and AIDS Center, Kaplan Medical Center, Hebrew University Hadassah Medical School, Rehovot 76100, Israel
| | | | | | | | | |
Collapse
|