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1.
Value Health ; 20(10): 1245-1251, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29241883

RESUMO

BACKGROUND: Many health technology assessment (HTA) agencies express a preference for randomized controlled trial evidence when appraising health technologies; nevertheless, it is not always feasible or ethical to conduct such comparative trials. OBJECTIVES: To assess the role of noncomparative evidence in HTA decision making. METHODS: The Web sites of the National Institute for Health and Care Excellence (NICE) in the United Kingdom, the Canadian Agency for Drugs and Technologies in Health (CADTH) in Canada, and the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen [IQWiG]) in Germany were searched for single HTA reports (published between January 2010 and December 2015). The product, indication, outcome, and clinical evidence presented (comparative/noncomparative) were double-extracted, with any discrepancies reconciled. A noncomparative study was defined as any study not presenting results against another treatment (including placebo or best supportive care), regardless of phase or setting, including dose-ranging studies. RESULTS: A total of 549 appraisals were extracted. Noncomparative evidence was considered in 38% (45 of 118) of NICE submissions, 13% (34 of 262) of CADTH submissions, and 12% (20 of 169) of IQWiG submissions. Evidence submissions based exclusively on noncomparative evidence were presented in only 4% (5 of 118) of NICE appraisals, 6% (16 of 262) of CADTH appraisals, and 4% (6 of 169) of IQWiG appraisals. Most drugs appraised solely on the basis of noncomparative evidence were indicated for cancer or hepatitis C. Positive outcome rates (encompassing recommended/restricted/added-benefit decisions) for submissions presenting only noncomparative evidence were similar to overall recommendation rates for CADTH (69% vs. 68%, respectively), but were numerically lower for NICE (60% vs. 84%, respectively) and IQWiG (17% vs. 38%, respectively) (P > 0.05 for all). CONCLUSIONS: Noncomparative studies can be viewed as acceptable clinical evidence by HTA agencies when these study designs are justifiable and when treatment effect can be convincingly demonstrated, but their use is currently limited.


Assuntos
Tecnologia Biomédica , Tomada de Decisões , Projetos de Pesquisa , Avaliação da Tecnologia Biomédica/métodos , Canadá , Medicina Baseada em Evidências , Alemanha , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Reino Unido
2.
Eur J Immunol ; 45(5): 1441-51, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25707450

RESUMO

Immune enhancement is desirable in situations where decreased immunity results in increased morbidity. We investigated whether blocking the surface inhibitory receptor PD-1 and/or p38 MAP kinase could enhance the proliferation of the effector memory CD8(+) T-cell subset that re-expresses CD45RA (EMRA) and exhibits characteristics of senescence, which include decreased proliferation and telomerase activity but increased expression of the DNA damage response related protein γH2AX. Blocking of both PD-1 and p38 MAPK signaling in these cells enhanced proliferation and the increase was additive when both pathways were inhibited simultaneously in both young and old human subjects. In contrast, telomerase activity in EMRA CD8(+) T cells was only enhanced by blocking the p38 but not the PD-1 signaling pathway, further indicating that nonoverlapping signaling pathways were involved. Although blocking p38 MAPK inhibits TNF-α secretion in the EMRA population, this decrease was counteracted by the simultaneous inhibition of PD-1 signaling in these cells. Therefore, end-stage characteristics of EMRA CD8(+) T cells are stringently controlled by distinct and reversible cell signaling events. In addition, the inhibition of PD-1 and p38 signaling pathways together may enable the enhancement of proliferation of EMRA CD8(+) T cells without compromising their capacity for cytokine secretion.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/imunologia , Envelhecimento/patologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Proliferação de Células , Senescência Celular/imunologia , Citocinas/metabolismo , Histonas/metabolismo , Humanos , Memória Imunológica , Antígenos Comuns de Leucócito/metabolismo , Sistema de Sinalização das MAP Quinases , Receptor de Morte Celular Programada 1/imunologia , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Telomerase/metabolismo , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia
3.
J Immunol ; 187(5): 2093-100, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21788446

RESUMO

Persistent viral infections and inflammatory syndromes induce the accumulation of T cells with characteristics of terminal differentiation or senescence. However, the mechanism that regulates the end-stage differentiation of these cells is unclear. Human CD4(+) effector memory (EM) T cells (CD27(-)CD45RA(-)) and also EM T cells that re-express CD45RA (CD27(-)CD45RA(+); EMRA) have many characteristics of end-stage differentiation. These include the expression of surface KLRG1 and CD57, reduced replicative capacity, decreased survival, and high expression of nuclear γH2AX after TCR activation. A paradoxical observation was that although CD4(+) EMRA T cells exhibit defective telomerase activity after activation, they have significantly longer telomeres than central memory (CM)-like (CD27(+)CD45RA(-)) and EM (CD27(-)CD45RA(-)) CD4(+) T cells. This suggested that telomerase activity was actively inhibited in this population. Because proinflammatory cytokines such as TNF-α inhibited telomerase activity in T cells via a p38 MAPK pathway, we investigated the involvement of p38 signaling in CD4(+) EMRA T cells. We found that the expression of both total and phosphorylated p38 was highest in the EM and EMRA compared with that of other CD4(+) T cell subsets. Furthermore, the inhibition of p38 signaling, especially in CD4(+) EMRA T cells, significantly enhanced their telomerase activity and survival after TCR activation. Thus, activation of the p38 MAPK pathway is directly involved in certain senescence characteristics of highly differentiated CD4(+) T cells. In particular, CD4(+) EMRA T cells have features of telomere-independent senescence that are regulated by active cell signaling pathways that are reversible.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Senescência Celular/imunologia , Ativação Linfocitária/imunologia , Subpopulações de Linfócitos T/imunologia , Telomerase/imunologia , Adulto , Western Blotting , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/imunologia , Separação Celular , Citometria de Fluxo , Humanos , Memória Imunológica/imunologia , Hibridização in Situ Fluorescente , Antígenos Comuns de Leucócito/biossíntese , Antígenos Comuns de Leucócito/imunologia , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/citologia , Telomerase/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/biossíntese , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Immunology ; 135(4): 355-63, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22211948

RESUMO

Highly differentiated CD8(+) CD28(-) CD27(-) T cells have short telomeres, defective telomerase activity and reduced capacity for proliferation. In addition, these cells express increased levels of inhibitory receptors and display defective Akt(ser(473)) phosphorylation following activation. It is not known whether signalling via programmed death 1 (PD-1) contributes to any of the attenuated differentiation-related functional changes in CD8(+) T cells. To address this we blocked PD-1 signalling during T-cell receptor (TCR) activation using antibodies against PD-1 ligand 1 (PDL1) and PDL2. This resulted in a significant enhancement of Akt(ser(473)) phosphorylation and TCR-induced proliferative activity of highly differentiated CD8(+) CD28(-) CD27(-) T cells. In contrast, the reduced telomerase activity in these cells was not altered by blockade of PDL1/2. We also demonstrate that PD-1 signalling can inhibit the proliferative response in primary human CD8(+) T cells from both young and older humans. These data collectively highlight that some, but not all, functional changes that arise during progressive T-cell differentiation and during ageing are maintained actively by inhibitory receptor signalling.


Assuntos
Envelhecimento/imunologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular , Ativação Linfocitária , Receptor de Morte Celular Programada 1/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Humanos , Ativação Linfocitária/imunologia , Fosforilação , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Adulto Jovem
5.
J Immunol ; 184(7): 3417-23, 2010 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-20176738

RESUMO

Short telomeres of circulating leukocytes are a risk factor for age-related diseases, such as atherosclerosis, but the exact mechanisms generating variations in telomere length are unknown. We hypothesized that induction of differentiated T cells during chronic CMV infection would affect T cell telomere length. To test this, we measured the amount of differentiated T cells and telomere length of lymphocytes during primary CMV infection as well as CMV-seropositive and -seronegative healthy individuals. After primary CMV infection, we observed an increase in highly differentiated cells that coincided with a steep drop in telomere length. Moreover, we found in a cohort of 159 healthy individuals that telomere shortening was more rapid in CMV-seropositive individuals and correlated with the amount of differentiated T cells in both CD4(+) T cells and CD8(+) T cells. Finally, we found that telomere length measured in blood leukocytes is correlated with lymphocyte telomere length. Thus, CMV infection induces a strong decrease in T cell telomere length, which can be explained by changes in the composition of the circulating lymphocyte pool.


Assuntos
Infecções por Citomegalovirus/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T/patologia , Telômero/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Diferenciação Celular/imunologia , Separação Celular , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/patologia , DNA Viral/sangue , Citometria de Fluxo , Imunofluorescência , Ganciclovir/uso terapêutico , Humanos , Hibridização in Situ Fluorescente , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Telômero/virologia , Viremia/tratamento farmacológico , Adulto Jovem
6.
Expert Rev Pharmacoecon Outcomes Res ; 22(1): 131-137, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33980118

RESUMO

BACKGROUND: The National Institute for Health and Care Excellence (NICE) makes recommendations on the reimbursement of new drugs utilizing an Incremental Cost-Effectiveness Ratio (ICER) threshold range that has been in use since 2004 and has remained unchanged. RESEARCH DESIGN AND METHODS: To model how the NICE cost-effectiveness thresholds would vary if inflation was accounted for and their potential effects on appraisal outcomes, all single technology appraisal (STA) recommendations published in 2019 were identified. The outcome and most plausible ICERs were then evaluated against thresholds, after taking inflation into account. RESULTS: 41 STAs with base-case ICERs were identified. For general STAs, 46% of ICERs were ≤£20,000/QALY, 27% were £20,000-£30,000/QALY and 27% >£30,000/QALY. Cumulatively, there was a 43% decrease in the purchasing power of the pound from 2004 to 2019 due to inflation. To compensate, the NICE ICER threshold would have to increase to £28,584-£42,876/QALY. Using inflation-adjusted thresholds led to an absolute increase of 18% and 12% of STAs whose ICERs fell below the lower and upper bounds of this threshold range, respectively. CONCLUSION: By not adjusting for inflation, the NICE ICER thresholds have declined in real terms. Whether ICER thresholds should be dynamic to reflect factors like inflation requires further research.


Assuntos
Academias e Institutos , Inflação , Medicina Estatal , Academias e Institutos/economia , Análise Custo-Benefício , Humanos , Medicina Estatal/economia , Reino Unido
7.
Blood ; 113(26): 6619-28, 2009 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-19406987

RESUMO

Highly differentiated CD8+CD28-CD27- T cells have short telomeres, defective telomerase activity, and reduced capacity for proliferation, indicating that they are close to replicative senescence. In addition, these cells express increased levels of the senescence-associated inhibitory receptor KLRG1 and have poor capacity for IL-2 synthesis and defective Akt (ser(473)) phosphorylation after activation. It is not known whether signaling via KLRG1 contributes to any of the attenuated differentiation-related functional changes in CD8+ T cells. To address this, we blocked KLRG1 signaling during T-cell receptor activation using antibodies against its major ligand, E-cadherin. This resulted in a significant enhancement of Akt (ser(473)) phosphorylation and T-cell receptor-induced proliferative activity of CD8+CD28-CD27- T cells. Furthermore, the increase of proliferation was directly linked to the Akt-mediated induction of cyclin D and E and reduction in the cyclin inhibitor p27 expression. In contrast, the reduced telomerase activity in highly differentiated CD8+CD28(-)CD27- T cells was not altered by KLRG1 blockade, indicating the involvement of other mechanisms. This is the first demonstration of a functional role for KLRG1 in primary human CD8+ T cells and highlights that certain functional defects that arise during progressive T-cell differentiation toward replicative senescence are maintained actively by inhibitory receptor signaling.


Assuntos
Envelhecimento/imunologia , Linfócitos T CD8-Positivos/imunologia , Lectinas Tipo C/fisiologia , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transativadores/fisiologia , Adulto , Idoso , Antígenos CD28/análise , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/enzimologia , Caderinas/antagonistas & inibidores , Diferenciação Celular , Senescência Celular , Ciclina D2 , Ciclina E/biossíntese , Ciclina E/genética , Inibidor de Quinase Dependente de Ciclina p27/biossíntese , Inibidor de Quinase Dependente de Ciclina p27/genética , Ciclinas/biossíntese , Ciclinas/genética , Feminino , Humanos , Lectinas Tipo C/antagonistas & inibidores , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Fosfosserina/análise , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Receptores Imunológicos , Telômero/ultraestrutura , Transativadores/antagonistas & inibidores , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/análise , Adulto Jovem
8.
Pharmaceuticals (Basel) ; 13(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33213079

RESUMO

INTRODUCTION: Biosimilars have the potential to enhance the sustainability of evolving health care systems. A sustainable biosimilars market requires all stakeholders to balance competition and supply chain security. However, there is significant variation in the policies for pricing, procurement, and use of biosimilars in the European Union. A modified Delphi process was conducted to achieve expert consensus on biosimilar market sustainability in Europe. METHODS: The priorities of 11 stakeholders were explored in three stages: a brainstorming stage supported by a systematic literature review (SLR) and key materials identified by the participants; development and review of statements derived during brainstorming; and a facilitated roundtable discussion. RESULTS: Participants argued that a sustainable biosimilar market must deliver tangible and transparent benefits to the health care system, while meeting the needs of all stakeholders. Key drivers of biosimilar market sustainability included: (i) competition is more effective than regulation; (ii) there should be incentives to ensure industry investment in biosimilar development and innovation; (iii) procurement processes must avoid monopolies and minimize market disruption; and (iv) principles for procurement should be defined by all stakeholders. However, findings from the SLR were limited, with significant gaps on the impact of different tender models on supply risks, savings, and sustainability. CONCLUSIONS: A sustainable biosimilar market means that all stakeholders benefit from appropriate and reliable access to biological therapies. Failure to care for biosimilar market sustainability may impoverish biosimilar development and offerings, eventually leading to increased cost for health care systems and patients, with fewer resources for innovation.

9.
Clinicoecon Outcomes Res ; 11: 199-219, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30936729

RESUMO

OBJECTIVES: The introduction of innovative, high-cost oncology treatments, coupled with mounting budgetary pressures, necessitates value trade-offs across cancer types. Defining value is critical to informing decision-making. A cost-value analysis tool was used to assess relative clinical value from a US perspective using multiple outcome metrics for a variety of metastatic cancers. METHODS: Literature published (January 1, 2000-August 31, 2016) was reviewed to identify outcome metrics for approved treatments for metastatic cancers. Data were extracted or derived for median and mean overall survival (OS), landmark survival rates, and other survival metrics, and compared across treatments vs their respective trial comparators, with and without considering costs. RESULTS: Reported survival metrics varied by agent within cancer type. For treatment of prostate cancer, abiraterone yielded the highest improvement in 1-year survival rate (13.7%, previously treated), whereas enzalutamide yielded the highest median OS improvement (4.8 months, previously treated) and sipuleucel-T, the highest mean OS improvement (3.6 months, previously untreated) vs their respective trial comparators. For treatment of non-small cell lung cancer vs their respective trial comparators, nivolumab yielded the highest improvement in mean OS (11.9 months) and 3-year survival rate (12.6%), each in previously treated squamous disease, whereas afatinib yielded the highest median OS improvement (4.1 months, previously untreated EGFR del19 and L858R mutants). Cost-value analysis results varied with the applied survival metric. CONCLUSIONS: Although median OS is the traditional gold standard oncology efficacy metric, it fails to capture long-term survival benefits-the ultimate goal of cancer treatment-offered by new treatment modalities. Diverse metrics are needed for comprehensive value assessments of cancer therapies.

10.
Value Health Reg Issues ; 6: 143-149, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-29698188

RESUMO

BACKGROUND: Oncology drugs lacking supportive phase III trial data have achieved Food and Drug Administration (FDA) and European Medicines Agency (EMA) regulatory approval and even European reimbursement approval where no therapeutic alternative exists and early-stage data indicate dramatic clinical benefits. OBJECTIVE: This research aimed to compare under what circumstances oncologics can obtain both regulatory and reimbursement approval in Australia on this basis. METHODS: Therapeutic Goods Administration (TGA) Australian Public Assessment Reports, EMA, FDA, and Pharmaceutical Benefits Advisory Committee (PBAC) Public Summary Documents were extracted for any oncologic indication appraised in Australia on a pivotal trial package lacking phase III data, excluding pediatric indications and new formulations. RESULTS: Australian Public Assessment Reports were available for six TGA-appraised oncologics across seven indications on such a data package: five of seven approved, one of seven restricted, and one of seven rejected. The EMA and the FDA issued recommendations on these indications an average of 1 and 2 years earlier, respectively. The PBAC appraised six oncologics across 10 indications on such a data package, with four (nilotinib, dasatinib, imatinib, and brentuximab vedotin) approved and two rejected (cetuximab and bevacizumab). Seven of the eight approved indications required multiple submissions, with inadequate clinical data frequently cited as key. Six of the eight PBAC-approved indications included economic modeling on a cost-benefit approach. CONCLUSIONS: The TGA will approve oncologics that offer potentially substantial clinical benefits on the basis of an indirect comparison of single-arm trials but at a delay versus the EMA and the FDA. The PBAC reimbursement approval also requires more rigorous supportive clinical data and acceptable cost-effectiveness as demonstrated on a cost-benefit or cost-quality-adjusted life-year metric.

11.
J Clin Invest ; 124(9): 4004-16, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25083993

RESUMO

T cell senescence is thought to contribute to immune function decline, but the pathways that mediate senescence in these cells are not clear. Here, we evaluated T cell populations from healthy volunteers and determined that human CD8+ effector memory T cells that reexpress the naive T cell marker CD45RA have many characteristics of cellular senescence, including decreased proliferation, defective mitochondrial function, and elevated levels of both ROS and p38 MAPK. Despite their apparent senescent state, we determined that these cells secreted high levels of both TNF-α and IFN-γ and showed potent cytotoxic activity. We found that the senescent CD45RA-expressing population engaged anaerobic glycolysis to generate energy for effector functions. Furthermore, inhibition of p38 MAPK signaling in senescent CD8+ T cells increased their proliferation, telomerase activity, mitochondrial biogenesis, and fitness; however, the extra energy required for these processes did not arise from increased glucose uptake or oxidative phosphorylation. Instead, p38 MAPK blockade in these senescent cells induced an increase in autophagy through enhanced interactions between p38 interacting protein (p38IP) and autophagy protein 9 (ATG9) in an mTOR-independent manner. Together, our findings describe fundamental metabolic requirements of senescent primary human CD8+ T cells and demonstrate that p38 MAPK blockade reverses senescence via an mTOR-independent pathway.


Assuntos
Autofagia/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Complexos Multiproteicos/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Adulto , Proteínas Relacionadas à Autofagia , Senescência Celular , Dano ao DNA , Glicólise , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Potencial da Membrana Mitocondrial , Proteínas de Membrana/fisiologia , Mitocôndrias/fisiologia , Fosforilação Oxidativa , Proteínas de Transporte Vesicular/fisiologia
12.
Age (Dordr) ; 35(3): 563-72, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22252437

RESUMO

Ageing is accompanied by alterations to T-cell immunity and also by a low-grade chronic inflammatory state termed inflammaging. The significance of these phenomena is highlighted by their being predictors of earlier mortality. We have recently published that the proinflammatory cytokine TNFα is a strong inducer of CD4(+) T-cell senescence and T-cell differentiation, adding to the growing body of literature implicating proinflammatory molecules in mediating these critical age-related T-cell alterations. Moreover, the inflammatory process is also being increasingly implicated in the pathogenesis of many common and severe age-related diseases, including cancer, cardiovascular diseases and type 2 diabetes. Furthermore, major age-related risk factors for poor health, such as obesity, stress and smoking, are also associated with an upregulation in systemic inflammatory markers. We propose the idea that the ensuing inflammatory response to influenza infection propagates cardiovascular diseases and constitutes a major cause of influenza-related mortality. While inflammation is not a negative phenomenon per se, this age-related dysregulation of inflammatory responses may play crucial roles driving age-related pathologies, T-cell immunosenescence and CMV reactivation, thereby underpinning key features of the ageing process.


Assuntos
Envelhecimento/imunologia , Citocinas/metabolismo , Inflamação/imunologia , Longevidade/fisiologia , Linfócitos T , Envelhecimento/patologia , Animais , Citocinas/imunologia , Humanos , Inflamação/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/patologia
13.
Hum Immunol ; 74(3): 302-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23220495

RESUMO

The dysregulated immune response to CMV constitutes a major force driving T cell immunosenescence and growing evidence suggests that it is not a benign virus in old age. We show here that the PD-1/L pathway defines a reversible defect in CMV specific CD8(+) T cell proliferative responses in both young and old individuals. More specifically, highly differentiated CD45RA(+)CD27(-) CMV-specific CD8(+) T cells exhibit a proliferative deficit compared their central and effector memory counterparts, which is reversed following PD-L blockade. However, we also report that HLA-B(∗)07/TPR specific CD8(+) T cells express higher levels of PD-1 than HLA-A(∗)02/NLV specific cells and HLA-A(∗)02 individuals show a higher proliferative response to PD-L blockade, than HLA-B(∗)07 individuals, which we postulate may be due to the differing functional avidities for these two CMV-specific CD8(+) T cells populations. Nevertheless data presented here demonstrate that CMV-specific CD8(+) T cells can be functionally enhanced by perturbation of the PD-1/L signalling pathway, whose manipulation may provide a therapeutic modality to combat age-associated immune decline.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Citomegalovirus/imunologia , Antígenos HLA/imunologia , Receptor de Morte Celular Programada 1/imunologia , Transdução de Sinais/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno B7-H1/imunologia , Antígeno B7-H1/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Diferenciação Celular/imunologia , Proliferação de Células , Células Cultivadas , Citomegalovirus/fisiologia , Citometria de Fluxo , Antígenos HLA/metabolismo , Antígenos HLA-A/imunologia , Antígenos HLA-A/metabolismo , Antígenos HLA-B/imunologia , Antígenos HLA-B/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/metabolismo , Adulto Jovem
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