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1.
AIDS Res Hum Retroviruses ; 40(1): 1-6, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37022787

RESUMO

Compared to young heterosexual men, young sexual and gender minorities (YSGM) have elevated systemic inflammation and unique intestinal microbial profiles, influenced by HIV infection and substance use. However, links between cannabis use and microbial dysbiosis in this population have not been well described. In this pilot study, we aimed to characterize the complex interrelationships between cannabis use and microbial community structure in YSGM in relationship to HIV status. Cannabis use was assessed by self-administered Cannabis Use Disorder Identification Test (CUDIT) questionnaires and rectal microbial community alpha-diversity metrics were assessed via 16S ribosomal ribonucleic acid (rRNA) sequencing in a subset of YSGM (n = 42) in the RADAR cohort (aged 16-29) in Chicago. Multivariable regression models were used to assess the relationship between cannabis use and microbiome alpha-diversity metrics, adjusting for HIV status and other risk characteristics, including inflammation, which was evaluated by plasma levels of C-reactive protein (CRP). Problematic cannabis use, but not general use, was significantly inversely associated with microbial community richness (Adj. Beta = -8.13; 95% confidence interval [CI]: -15.68 to -0.59) and Shannon diversity (Adj. Beta = -0.04; 95% CI: -0.07 to 0.009). No significant association was observed between CUDIT score and community evenness, nor was any significant moderation observed by HIV status. We observed that problematic cannabis use was associated with reduced microbial community richness and Shannon diversity, adjusting for within population differences in inflammation and HIV status. Future research should aim to assess how cannabis use contributes to microbiome-related health factors among YSGM and if decreasing cannabis use can restore gut microbial community structure.


Assuntos
Cannabis , Infecções por HIV , Minorias Sexuais e de Gênero , Transtornos Relacionados ao Uso de Substâncias , Humanos , Masculino , Infecções por HIV/epidemiologia , Cannabis/genética , Projetos Piloto , Inflamação , RNA Ribossômico 16S/genética
3.
Ann LGBTQ Public Popul Health ; 4(1): 1-13, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37599862

RESUMO

Past research has suggested that sexual and gender minorities experience elevated levels of systemic inflammation which in turn has been linked to worse mental health outcomes. Therefore, the goals of this work are to develop a better understanding of the relationship between mental health variables and inflammation among this high-risk population. Data were collected among a sample of young men who have sex with men and transgender women (YMSM/TGW, N=685) aged 16-20 at the time of enrollment. Multiplex plasma cytokine and inflammatory biomarkers were quantified. Mental health variables were self-reported and included perceived stress, depression, and suicidal ideation. Latent profile analyses (i.e., latent class analyses intended for continuous variables) were utilized to identify four unique profiles of individuals with similar inflammatory markers followed by adjusted multinomial logistic regression to estimate the association between inflammatory profiles and mental health variables. Participants experienced moderate levels of perceived stress, normal levels of depression and ten percent reported suicidal ideation in the past six months. Multinomial regression models indicated that being in the highest inflammation profile, compared to the lowest inflammation profile, was significantly associated only with increased perceived stress and suicidal ideation. In sum, we observed significant relationships between inflammation and both perceived stress and suicidal ideation, but not between inflammation and depression. Future research should continue to assess these relationships using longitudinal data as they are intricate and likely bidirectional and may be key to reducing health disparities among this population.

4.
Commun Biol ; 5(1): 878, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-36028574

RESUMO

Translocated lipopolysaccharide (LPS) activates monocytes via TLR4 and is hypothesized to increase cardiovascular disease risk in persons living with HIV. We tested whether mTOR activity supports LPS-stimulated monocyte production of pro-inflammatory cytokines and tissue factor (TF), as it propels the inflammatory response in several immune cell types besides monocytes. However, multi-omics analyses here demonstrate that mTOR activates a metabolic pathway that limits abundance of these gene products in monocytes. Treatment of primary human monocytes with catalytic mTOR inhibitors (mTORi) increased LPS-induced polyfunctional responses, including production of IL-1ß, IL-6, and the pro-coagulant, TF. NF-κB-driven transcriptional activity is enhanced with LPS stimulation after mTORi treatment to increase expression of F3 (TF). Moreover, intracellular NAD+ availability is restricted due to decreased salvage pathway synthesis. These results document mTOR-mediated restraint of the LPS-induced transcriptional response in monocytes and a metabolic mechanism informing strategies to reverse enhanced risk of coagulopathy in pro-inflammatory states.


Assuntos
Lipopolissacarídeos , Monócitos , Serina-Treonina Quinases TOR , Citocinas , Humanos , Serina-Treonina Quinases TOR/metabolismo , Tromboplastina
5.
J Parasitol ; 108(2): 166-179, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35357506

RESUMO

A study of cestode specimens that were collected during survey work on elasmobranchs collected from Taiwan and Northern Territory, Australia, revealed the presence of 1 new combination into the genus Stillabothrium (Rhinebothriidea: Escherbothriidae) and 2 new species of the genus. Phyllobothrium biacetabulatum, collected from Rhinobatos schlegelii, is transferred to Stillabothrium and its description is emended, as is the diagnosis for the genus Stillabothrium and the family Escherbothriidae. Stillabothrium biacetabulatum n. comb. differs from existing species of the genus in that the face of its bothridia is laced with a network of longitudinal and horizontal muscle fibers that do not contribute to the formation of septa. Stillabothrium lunae n. sp. is described from Himantura leoparda and differs from existing species of the genus in that its bothridium possesses an anterior field of 7-8 loculi that are wider than long. Stillabothrium mariae n. sp. is described from Maculabatis astra. This species differs from all species of Stillabothrium except Stillabothrium campbelli in possessing 10-12 horizontally oriented bothridial loculi. Stillabothrium mariae n. sp. differs from S. campbelli in having longer bothridia and from all other species of Stillabothrium in that it lacks, rather than possesses, conspicuous septa and loculi that are longer than wide in the posterior region of its bothridia. Bayesian and parsimony-bootstrap analysis of 28S rDNA revealed S. biacetabulatum n. comb., S. lunae n. sp., and S. mariae n. sp. to be part of Clade 1 of Stillabothrium, with S. biacetabulatum n. comb. being the sister species to S. mariae n. sp. Stillabothrium lunae n. sp. was found to be the sister species to Stillabothrium borneoense.


Assuntos
Cestoides , Elasmobrânquios , Rajidae , Animais , Teorema de Bayes , Cestoides/genética , Northern Territory/epidemiologia
6.
Sci Adv ; 7(41): eabg5841, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34613775

RESUMO

Regional delivery of chimeric antigen receptor (CAR) T cells in glioblastoma represents a rational therapeutic approach as an alternative to intravenous administration to avoid the blood-brain barrier impediment. Here, we developed a fibrin gel that accommodates CAR-T cell loading and promotes their gradual release. Using a model of subtotal glioblastoma resection, we demonstrated that the fibrin-based gel delivery of CAR-T cells within the surgical cavity enables superior antitumor activity compared to CAR-T cells directly inoculated into the tumor resection cavity.

7.
Otol Neurotol ; 42(10): e1592-e1599, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34353983

RESUMO

HYPOTHESIS: We compared two means of mitigating the effect of sternocleidomastoid (SCM) contraction strength on the cervical vestibular evoked myogenic potential (cVEMP): contraction matching and amplitude normalization. BACKGROUND: SCM muscle contraction strength affects the amplitude of the cVEMP which can impact measures of inter-side asymmetry and diagnostic outcomes. METHODS: In 19 normal subjects, we investigated the effect of muscle contraction variation within a cVEMP recording. We then compared cVEMP recordings on the right and left sides with matched and unmatched muscle contraction strength using raw amplitudes and amplitude ratios (i.e., normalized amplitudes). RESULTS: Contraction variability had significant effects on small sections of a cVEMP recording, but there was no significant effect on overall cVEMP amplitude, suggesting that the cVEMP is relatively unaffected by variable effort during a recording. Matching the contraction across the two sides (d = 0.53, p = 0.016) and amplitude normalization (d = 0.43, p = 0.004) both significantly reduced inter-side asymmetry, but normalization had no additional benefit once the sides were matched (interaction effect, p = 0.019). cVEMPs recorded with matched contractions had the smallest range of asymmetry values. CONCLUSION: The study shows that controlling the background contraction during a cVEMP recording, either by using similar contractions for each trial or by normalizing the amplitude, reduces cVEMP asymmetry and can prevent incorrect results in the minority of subjects who make asymmetric muscle contractions.


Assuntos
Potenciais Evocados Miogênicos Vestibulares , Estimulação Acústica , Eletromiografia , Humanos , Contração Muscular/fisiologia , Músculos do Pescoço/fisiologia , Potenciais Evocados Miogênicos Vestibulares/fisiologia
8.
BMJ Open ; 11(3): e048196, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33771832

RESUMO

BACKGROUND: Brace effectiveness for knee osteoarthritis (OA) remains unclear and international guidelines offer conflicting recommendations. Our trial will determine the clinical and cost-effectiveness of adding knee bracing (matched to patients' clinical and radiographic presentation and with adherence support) to a package of advice, written information and exercise instruction delivered by physiotherapists. METHODS AND ANALYSIS: A multicentre, pragmatic, two-parallel group, single-blind, superiority, randomised controlled trial with internal pilot and nested qualitative study. 434 eligible participants with symptomatic knee OA identified from general practice, physiotherapy referrals and self-referral will be randomised 1:1 to advice, written information and exercise instruction and knee brace versus advice, written information and exercise instruction alone. The primary analysis will be intention-to-treat comparing treatment arms on the primary outcome (Knee Osteoarthritis Outcomes Score (KOOS)-5) (composite knee score) at the primary endpoint (6 months) adjusted for prespecified covariates. Secondary analysis of KOOS subscales (pain, other symptoms, activities of daily living, function in sport and recreation, knee-related quality of life), self-reported pain, instability (buckling), treatment response, physical activity, social participation, self-efficacy and treatment acceptability will occur at 3, 6, and 12 months postrandomisation. Analysis of covariance and logistic regression will model continuous and dichotomous outcomes, respectively. Treatment effect estimates will be presented as mean differences or ORs with 95% CIs. Economic evaluation will estimate cost-effectiveness. Semistructured interviews to explore acceptability and experiences of trial interventions will be conducted with participants and physiotherapists delivering interventions. ETHICS AND DISSEMINATION: North West Preston Research Ethics Committee, the Health Research Authority and Health and Care Research in Wales approved the study (REC Reference: 19/NW/0183; IRAS Reference: 247370). This protocol has been coproduced with stakeholders including patients and public. Findings will be disseminated to patients and a range of stakeholders. TRIAL REGISTRATION NUMBER: ISRCTN28555470.


Assuntos
Osteoartrite do Joelho , Atividades Cotidianas , Análise Custo-Benefício , Humanos , Estudos Multicêntricos como Assunto , Osteoartrite do Joelho/terapia , Atenção Primária à Saúde , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Método Simples-Cego , Resultado do Tratamento , País de Gales
9.
Sci Rep ; 11(1): 4816, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649360

RESUMO

The use of marijuana is highly prevalent among young men who have sex with men (YMSM). Past work has also shown that inflammation is elevated among YMSM, independent of HIV status. Here, we aim to examine the relationship between marijuana use and inflammation among this high-risk cohort, relative to use of other substances. Data were collected among YMSM aged 16-29 in Chicago. Multiplex cytokine and inflammatory biomarker assays were run on plasma from all persons living with HIV (PLWH) (n = 195) and a subset of HIV-negative participants (n = 489). Bivariate analyses and multivariable models assessed relationships between various substances and inflammatory biomarkers. Models were stratified by HIV status and adjusted for demographic characteristics. Most participants reported use of marijuana in the past 30 days (416, 60.8%). Mean blood C-reactive protein (CRP) levels were above the upper limit of normal (3.0 mg/L), indicative of increased risk for cardiovascular disease (mean CRP was 3.9 mg/L; SD = 8.5). In adjusted, stratified analyses, CRP was significantly lower among participants reporting frequent marijuana use (≥ 6 times per month), relative to those reporting never using marijuana, (ß = - 0.38; 95% CI: - 0.73, - 0.03). However, this was entirely accounted for by an association among the HIV-negative participants and there was no significant association between marijuana use and blood CRP level among the PLWH. In summary, YMSM had markedly elevated marijuana use and blood CRP levels. Frequent marijuana use was associated with lower inflammation among only those not diagnosed with HIV. Further research is needed to explicate why there are differences between HIV-negative participants and PLWH and to leverage this information to characterize biological mechanisms by which marijuana decreases inflammation.


Assuntos
Proteína C-Reativa/metabolismo , Infecções por HIV/sangue , Fumar Maconha/sangue , Transtornos Relacionados ao Uso de Substâncias/sangue , Adolescente , Adulto , Proteína C-Reativa/genética , Cannabis/efeitos adversos , Chicago , Feminino , HIV/patogenicidade , Infecções por HIV/epidemiologia , Infecções por HIV/patologia , Infecções por HIV/virologia , Alucinógenos/efeitos adversos , Homossexualidade Masculina , Humanos , Masculino , Fumar Maconha/patologia , Fatores de Risco , Minorias Sexuais e de Gênero/psicologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/patologia , Transtornos Relacionados ao Uso de Substâncias/virologia , Adulto Jovem
10.
J Clin Endocrinol Metab ; 106(6): 1649-1667, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33619548

RESUMO

CONTEXT: ANGPTL8 (A8) plays a key role in determining the tissue fate of circulating triglycerides (TGs). Plasma A8 levels are associated with several parameters of glucose and TG metabolism, but the causality of these relationships and the contribution of genetic variants to differences in A8 levels have not been explored. OBJECTIVE: To characterize the frequency distribution of plasma A8 levels in a diverse population using a newly-developed enzyme-linked immunosorbent assay (ELISA) and to identify genetic factors contributing to differences in plasma A8 levels. METHODS: We studied a population-based sample of Dallas County, comprising individuals in the Dallas Heart Study (DHS-1, n = 3538; DHS-2, n = 3283), including 2131 individuals with repeated measurements 7 to 9 years apart (age 18-85 years; >55% female; 52% Black; 29% White; 17% Hispanic; and 2% other). The main outcome measures were associations of A8 levels with body mass index (BMI), plasma levels of glucose, insulin, lipids, and hepatic TGs, as well as DNA variants identified by exome-wide sequencing. RESULTS: A8 levels varied over a 150-fold range (2.1-318 ng/mL; median, 13.3 ng/mL) and differed between racial/ethnic groups (Blacks > Hispanics > Whites). A8 levels correlated with BMI, fasting glucose, insulin, and TG levels. A variant in A8, R59W, accounted for 17% of the interindividual variation in A8 levels but was not associated with the metabolic parameters correlated with plasma A8 concentrations. CONCLUSIONS: A8 levels were strongly associated with indices of glucose and TG metabolism, but the lack of association of genetic variants at the A8 locus that impact A8 levels with these parameters indicates that differences in A8 levels are not causally related to the associated metabolic phenotypes.


Assuntos
Proteínas Semelhantes a Angiopoietina/sangue , Metabolismo Energético/fisiologia , Patrimônio Genético , Hormônios Peptídicos/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína 8 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina/genética , Estudos de Coortes , Metabolismo Energético/genética , Etnicidade/genética , Etnicidade/estatística & dados numéricos , Feminino , Glucose/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/etnologia , Obesidade/genética , Obesidade/metabolismo , Hormônios Peptídicos/genética , Texas/epidemiologia , Triglicerídeos/metabolismo , Adulto Jovem
11.
Cell Rep ; 31(12): 107810, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32579936

RESUMO

Cellular metabolism governs the susceptibility of CD4 T cells to HIV-1 infection. Multiple early post-fusion steps of HIV-1 replication are restricted in resting peripheral blood CD4 T cells; however, molecular mechanisms that underlie metabolic control of these steps remain undefined. Here, we show that mTOR activity following T cell stimulatory signals overcomes metabolic restrictions in these cells by enabling the expansion of dNTPs to fuel HIV-1 reverse transcription (RT), as well as increasing acetyl-CoA to stabilize microtubules that transport RT products. We find that catalytic mTOR inhibition diminishes the expansion of pools of both of these metabolites by limiting glucose and glutamine utilization in several pathways, thereby suppressing HIV-1 infection. We demonstrate how mTOR-coordinated biosyntheses enable the early steps of HIV-1 replication, add metabolic mechanisms by which mTOR inhibitors block HIV-1, and identify some metabolic modules downstream of mTOR as druggable targets for HIV-1 inhibition.


Assuntos
HIV-1/genética , HIV-1/metabolismo , Espaço Intracelular/metabolismo , Transcrição Reversa/genética , Serina-Treonina Quinases TOR/metabolismo , Acetilcoenzima A/metabolismo , Acetilação , Transporte Biológico , Linfócitos T CD4-Positivos/virologia , Citocinas/metabolismo , Retroalimentação Fisiológica , Glicólise , HIV-1/imunologia , HIV-1/fisiologia , Humanos , Lisina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Microtúbulos/metabolismo , Modelos Biológicos , Receptores de Antígenos de Linfócitos T/metabolismo , Tubulina (Proteína)/metabolismo , Replicação Viral/genética
12.
AIDS Res Hum Retroviruses ; 36(1): 92-95, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31523983

RESUMO

We determined HIV-1 pol gene sequences from self-collected rectal swabs of HIV-positive young men who have sex with men and transgender women. HIV-1 pol was amplified from 39/96 (41%) rectal swabs, including 29/77 (38%) prevalent and 10/19 (53%) incident HIV-1 infections (p < .001). Pol did not amplify from rectal swabs from participants with plasma viral load <1,000 copies/mL. Each rectal swab-derived amplicon consensus sequence was most closely related to the paired plasma virion RNA-derived sequence from the same participant. Results document a rectal mucosal source of HIV-1 in infected persons and suggest usefulness for noninvasive study of biological mechanisms underlying the epidemiologic risk to an insertive partner of HIV-1 acquisition during condomless anal sex.


Assuntos
Infecções por HIV/sangue , Infecções por HIV/virologia , HIV-1/genética , Filogenia , RNA Viral/sangue , Reto/virologia , Adolescente , Adulto , Chicago/epidemiologia , Estudos de Coortes , Feminino , Genes pol/genética , HIV-1/classificação , HIV-1/isolamento & purificação , Humanos , Masculino , Mucosa/virologia , Comportamento Sexual , Parceiros Sexuais , Minorias Sexuais e de Gênero , Manejo de Espécimes/métodos , Pessoas Transgênero , Carga Viral , Adulto Jovem
13.
EBioMedicine ; 47: 33-43, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31466914

RESUMO

BACKGROUND: The dismal survival of glioblastoma (GBM) patients urgently calls for the development of new treatments. Chimeric antigen receptor T (CAR-T) cells are an attractive strategy, but preclinical and clinical studies in GBM have shown that heterogeneous expression of the antigens targeted so far causes tumor escape, highlighting the need for the identification of new targets. We explored if B7-H3 is a valuable target for CAR-T cells in GBM. METHODS: We compared mRNA expression of antigens in GBM using TCGA data, and validated B7-H3 expression by immunohistochemistry. We then tested the antitumor activity of B7-H3-redirected CAR-T cells against GBM cell lines and patient-derived GBM neurospheres in vitro and in xenograft murine models. FINDINGS: B7-H3 mRNA and protein are overexpressed in GBM relative to normal brain in all GBM subtypes. Of the 46 specimens analyzed by immunohistochemistry, 76% showed high B7-H3 expression, 22% had detectable, but low B7-H3 expression and 2% were negative, as was normal brain. All 20 patient-derived neurospheres showed ubiquitous B7-H3 expression. B7-H3-redirected CAR-T cells effectively targeted GBM cell lines and neurospheres in vitro and in vivo. No significant differences were found between CD28 and 4-1BB co-stimulation, although CD28-co-stimulated CAR-T cells released more inflammatory cytokines. INTERPRETATION: We demonstrated that B7-H3 is highly expressed in GBM specimens and neurospheres that contain putative cancer stem cells, and that B7-H3-redirected CAR-T cells can effectively control tumor growth. Therefore, B7-H3 represents a promising target in GBM. FUND: Alex's Lemonade Stand Foundation; Il Fondo di Gio Onlus; National Cancer Institute; Burroughs Wellcome Fund.


Assuntos
Antígenos B7/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T/metabolismo , Animais , Antígenos de Neoplasias/imunologia , Antígenos B7/genética , Biomarcadores , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/terapia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Glioblastoma/imunologia , Glioblastoma/mortalidade , Glioblastoma/terapia , Humanos , Imunofenotipagem , Imunoterapia Adotiva , Camundongos , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/metabolismo , Linfócitos T/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Artigo em Inglês | MEDLINE | ID: mdl-28208789

RESUMO

Exposure to nature provides a wide range of health benefits. A significant proportion of these are delivered close to home, because this offers an immediate and easily accessible opportunity for people to experience nature. However, there is limited information to guide recommendations on its management and appropriate use. We apply a nature dose-response framework to quantify the simultaneous association between exposure to nearby nature and multiple health benefits. We surveyed ca. 1000 respondents in Southern England, UK, to determine relationships between (a) nature dose type, that is the frequency and duration (time spent in private green space) and intensity (quantity of neighbourhood vegetation cover) of nature exposure and (b) health outcomes, including mental, physical and social health, physical behaviour and nature orientation. We then modelled dose-response relationships between dose type and self-reported depression. We demonstrate positive relationships between nature dose and mental and social health, increased physical activity and nature orientation. Dose-response analysis showed that lower levels of depression were associated with minimum thresholds of weekly nature dose. Nearby nature is associated with quantifiable health benefits, with potential for lowering the human and financial costs of ill health. Dose-response analysis has the potential to guide minimum and optimum recommendations on the management and use of nearby nature for preventative healthcare.


Assuntos
Meio Ambiente , Comportamentos Relacionados com a Saúde , Nível de Saúde , Atividades de Lazer/psicologia , Saúde Mental , Natureza , Saúde da População Urbana , Adulto , Idoso , Estudos Transversais , Depressão/prevenção & controle , Inglaterra , Exercício Físico/psicologia , Feminino , Promoção da Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Características de Residência , Autorrelato , Ajustamento Social , Fatores de Tempo
15.
Mol Syst Biol ; 11(5): 803, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25953765

RESUMO

When cells are exposed to death ligands such as TRAIL, a fraction undergoes apoptosis and a fraction survives; if surviving cells are re-exposed to TRAIL, fractional killing is once again observed. Therapeutic antibodies directed against TRAIL receptors also cause fractional killing, even at saturating concentrations, limiting their effectiveness. Fractional killing arises from cell-to-cell fluctuations in protein levels (extrinsic noise), but how this results in a clean bifurcation between life and death remains unclear. In this paper, we identify a threshold in the rate and timing of initiator caspase activation that distinguishes cells that live from those that die; by mapping this threshold, we can predict fractional killing of cells exposed to natural and synthetic agonists alone or in combination with sensitizing drugs such as bortezomib. A phenomenological model of the threshold also quantifies the contributions of two resistance genes (c-FLIP and Bcl-2), providing new insight into the control of cell fate by opposing pro-death and pro-survival proteins and suggesting new criteria for evaluating the efficacy of therapeutic TRAIL receptor agonists.


Assuntos
Bortezomib/farmacologia , Caspase 8/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Apoptose , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células HEK293 , Células HeLa/efeitos dos fármacos , Humanos , Modelos Biológicos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
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