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1.
J Int AIDS Soc ; 23(9): e25622, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32996705

RESUMO

INTRODUCTION: The COVID-19 pandemic has impacted global health service delivery, including provision of HIV services. Countries with high HIV burden are balancing the need to minimize interactions with health facilities to reduce the risk of COVID-19 transmission, while delivering uninterrupted essential HIV prevention, testing and treatment services. Many of these adaptations in resource-constrained settings have not adequately accounted for the needs of pregnant and breastfeeding women, infants, children and adolescents. We propose whole-family, tailored programme adaptations along the HIV clinical continuum to protect the programmatic gains made in services. DISCUSSION: Essential HIV case-finding services for pregnant and breastfeeding women and children should be maintained and include maternal testing, diagnostic testing for infants exposed to HIV, index testing for children whose biological parents or siblings are living with HIV, as well as for children/adolescents presenting with symptoms concerning for HIV and comorbidities. HIV self-testing for children two years of age and older should be supported with caregiver and provider education. Adaptations include bundling services in the same visit and providing testing outside of facilities to the extent possible to reduce exposure risk to COVID-19. Virtual platforms can be used to identify vulnerable children at risk of HIV infection, abuse, harm or violence, and link them to necessary clinical and psychosocial support services. HIV treatment service adaptations for families should focus on family based differentiated service delivery models, including community-based ART initiation and multi-month ART dispensing. Viral load monitoring should not be a barrier to transitioning children and adolescents experiencing treatment failure to more effective ART regimens, and viral load monitoring for pregnant and breastfeeding women and children should be prioritized and bundled with other essential services. CONCLUSIONS: Protecting pregnant and breastfeeding women, infants, children and adolescents from acquiring SARS-CoV-2 while sustaining essential HIV services is an immense global health challenge. Tailored, family friendly programme adaptations for case-finding, ART delivery and viral load monitoring for these populations have the potential to limit SARS-CoV-2 transmission while ensuring the continuity of life-saving HIV case identification and treatment efforts.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Atenção à Saúde , Infecções por HIV/tratamento farmacológico , Pneumonia Viral/epidemiologia , Adolescente , Aleitamento Materno , COVID-19 , Criança , Pré-Escolar , Infecções por Coronavirus/prevenção & controle , Família , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Recursos em Saúde , Humanos , Lactente , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , SARS-CoV-2 , Carga Viral
3.
Int J MCH AIDS ; 7(1): 192-206, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30631638

RESUMO

BACKGROUND/OBJECTIVES: In the last decade, many strategies have called for integration of HIV and child survival platforms to reduce missed opportunities and improve child health outcomes. Countries with generalized HIV epidemics have been encouraged to optimize each clinical encounter to bend the HIV epidemic curve. This systematic review looks at integrated child health services and summarizes evidence on their health outcomes, service uptake, acceptability, and identified enablers and barriers. METHODS: Databases were systematically searched for peer-reviewed studies. Interventions of interest were HIV services integrated with: neonatal/child services for children <5 years, hospital care of children <5 years, immunizations, and nutrition services. Outcomes of interest were: health outcomes of children <5 years, integrated services uptake, acceptability, and enablers and barriers. PROSPERO ID: CRD42017082444. RESULTS: Twenty-eight articles were reviewed: 25 (89%) evaluated the integration of HIV services into child health platforms, while three articles (11%) investigated the integration of child health services into HIV platforms. Studies measured health outcomes of children (n=9); service uptake (n=18); acceptability of integrated services (n=8), and enablers and barriers to service integration (n=14). Service integration had positive effects on child health outcomes, HIV testing, and postnatal service uptake. Integrated services were generally acceptable, although confidentiality and stigma were concerns. CONCLUSION AND GLOBAL HEALTH IMPLICATIONS: Each clinical "touch point" with infants and children is an opportunity to provide comprehensive health services. In the current era of flat funding levels, integration of HIV and child health services is an effective, acceptable way to achieve positive child health outcomes.

4.
Trop Med Int Health ; 23(2): 136-148, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29164754

RESUMO

OBJECTIVES: Despite the success of Prevention of Mother-to-Child Transmission of HIV (PMTCT) programmes, low uptake of services and poor retention pose a formidable challenge to achieving the elimination of vertical HIV transmission in low- and middle-income countries. This systematic review summarises interventions that demonstrate statistically significant improvements in service uptake and retention of HIV-positive pregnant and breastfeeding women and their infants along the PMTCT cascade. METHODS: Databases were systematically searched for peer-reviewed studies. Outcomes of interest included uptake of services, such as antiretroviral therapy (ART) such as initiation, early infant diagnostic testing, and retention of HIV-positive pregnant and breastfeeding women and their infants. Interventions that led to statistically significant outcomes were included and mapped to the PMTCT cascade. An eight-item assessment tool assessed study rigour. PROSPERO ID: CRD42017063816. RESULTS: Of 686 citations reviewed, 11 articles met inclusion criteria. Ten studies detailed maternal outcomes and seven studies detailed infant outcomes in PMTCT programmes. Interventions to increase access to antenatal care (ANC) and ART services (n = 4) and those using lay cadres (n = 3) were most common. Other interventions included quality improvement (n = 2), mHealth (n = 1), and counselling (n = 1). One study described interventions in an Option B+ programme. Limitations included lack of HIV testing and counselling and viral load monitoring outcomes, small sample size, geographical location, and non-randomized assignment and selection of participants. CONCLUSIONS: Interventions including ANC/ART integration, family-centred approaches, and the use of lay healthcare providers are demonstrably effective in increasing service uptake and retention of HIV-positive mothers and their infants in PMTCT programmes. Future studies should include control groups and assess whether interventions developed in the context of earlier 'Options' are effective in improving outcomes in Option B+ programmes.


Assuntos
Infecções por HIV/prevenção & controle , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez/tratamento farmacológico , Adulto , Fármacos Anti-HIV/uso terapêutico , Continuidade da Assistência ao Paciente/organização & administração , Feminino , Humanos , Lactente , Recém-Nascido , Gravidez , Literatura de Revisão como Assunto , Adulto Jovem
5.
Blood ; 126(8): e1-e10, 2015 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-26124495

RESUMO

Growing interest in natural killer (NK) cell-based therapy for treating human cancer has made it imperative to develop new tools to measure early events in cell death. We recently demonstrated that protease-cleavable luciferase biosensors detect granzyme B and pro-apoptotic caspase activation within minutes of target cell recognition by murine cytotoxic lymphocytes. Here we report successful adaptation of the biosensor technology to assess perforin-dependent and -independent induction of death pathways in tumor cells recognized by human NK cell lines and primary cells. Cell-cell signaling via both Fc receptors and NK-activating receptors led to measurable luciferase signal within 15 minutes. In addition to the previously described aspartase-cleavable biosensors, we report development of granzyme A and granzyme K biosensors, for which no other functional reporters are available. The strength of signaling for granzyme biosensors was dependent on perforin expression in IL-2-activated NK effectors. Perforin-independent induction of apoptotic caspases was mediated by death receptor ligation and was detectable after 45 minutes of conjugation. Evidence of both FasL and TRAIL-mediated signaling was seen after engagement of Jurkat cells by perforin-deficient human cytotoxic lymphocytes. Although K562 cells have been reported to be insensitive to TRAIL, robust activation of pro-apoptotic caspases by NK cell-derived TRAIL was detectable in K562 cells. These studies highlight the sensitivity of protease-cleaved luciferase biosensors to measure previously undetectable events in live cells in real time. Further development of caspase and granzyme biosensors will allow interrogation of additional features of granzyme activity in live cells including localization, timing, and specificity.


Assuntos
Apoptose/fisiologia , Técnicas Biossensoriais , Granzimas/imunologia , Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Neoplasias/imunologia , Caspases/imunologia , Linhagem Celular Tumoral , Ativação Enzimática/fisiologia , Citometria de Fluxo , Granzimas/administração & dosagem , Humanos , Immunoblotting , Células Jurkat , Células K562 , Proteínas Recombinantes , Transfecção
6.
J Immunol ; 193(2): 519-28, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24928990

RESUMO

Activation of caspase-mediated apoptosis is reported to be a hallmark of both granzyme B- and Fas-mediated pathways of killing by CTLs; however, the kinetics of caspase activation remain undefined owing to an inability to monitor target cell-specific apoptosis in real time. We have overcome this limitation by developing a novel biosensor assay that detects continuous, protease-specific activity in target cells. Biosensors were engineered from a circularly permuted luciferase, linked internally by either caspase 3/7 or granzyme B/caspase 8 cleavage sites, thus allowing activation upon proteolytic cleavage by the respective proteases. Coincubation of murine CTLs with target cells expressing either type of biosensor led to a robust luminescent signal within minutes of cell contact. The signal was modulated by the strength of TCR signaling, the ratio of CTL/target cells, and the type of biosensor used. Additionally, the luciferase signal at 30 min correlated with target cell death, as measured by a (51)Cr-release assay. The rate of caspase 3/7 biosensor activation was unexpectedly rapid following granzyme B- compared with Fas-mediated signal induction in murine CTLs; the latter appeared gradually after a 90-min delay in perforin- or granzyme B-deficient CTLs. Remarkably, the Fas-dependent, caspase 3/7 biosensor signal induced by perforin-deficient human CTLs was also detectable after a 90-min delay when measured by redirected killing. Thus, we have used a novel, real-time assay to demonstrate the distinct pattern of caspase activation induced by granzyme B versus Fas in human and murine CTLs.


Assuntos
Caspases/imunologia , Granzimas/imunologia , Linfócitos T Citotóxicos/imunologia , Receptor fas/imunologia , Animais , Apoptose/imunologia , Sítios de Ligação/genética , Caspase 3/genética , Caspase 3/imunologia , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/imunologia , Caspase 7/metabolismo , Caspases/genética , Caspases/metabolismo , Linhagem Celular Tumoral , Testes Imunológicos de Citotoxicidade/métodos , Citotoxicidade Imunológica/genética , Citotoxicidade Imunológica/imunologia , Ativação Enzimática/imunologia , Granzimas/genética , Granzimas/metabolismo , Humanos , Luciferases/genética , Luciferases/metabolismo , Medições Luminescentes/métodos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Perforina/genética , Perforina/imunologia , Perforina/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/metabolismo , Fatores de Tempo , Receptor fas/metabolismo
7.
PLoS Pathog ; 8(4): e1002662, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22536156

RESUMO

Epstein-Barr virus (EBV) latently infects most of the human population and is strongly associated with lymphoproliferative disorders. EBV encodes several latency proteins affecting B cell proliferation and survival, including latent membrane protein 2A (LMP2A) and the EBV oncoprotein LMP1. LMP1 and LMP2A signaling mimics CD40 and BCR signaling, respectively, and has been proposed to alter B cell functions including the ability of latently-infected B cells to access and transit the germinal center. In addition, several studies suggested a role for LMP2A modulation of LMP1 signaling in cell lines by alteration of TRAFs, signaling molecules used by LMP1. In this study, we investigated whether LMP1 and LMP2A co-expression in a transgenic mouse model alters B cell maturation and the response to antigen, and whether LMP2A modulates LMP1 function. Naïve LMP1/2A mice had similar lymphocyte populations and antibody production by flow cytometry and ELISA compared to controls. In the response to antigen, LMP2A expression in LMP1/2A animals rescued the impairment in germinal center generation promoted by LMP1. LMP1/2A animals produced high-affinity, class-switched antibody and plasma cells at levels similar to controls. In vitro, LMP1 upregulated activation markers and promoted B cell hyperproliferation, and co-expression of LMP2A restored a wild-type phenotype. By RT-PCR and immunoblot, LMP1 B cells demonstrated TRAF2 levels four-fold higher than non-transgenic controls, and co-expression of LMP2A restored TRAF2 levels to wild-type levels. No difference in TRAF3 levels was detected. While modulation of other TRAF family members remains to be assessed, normalization of the LMP1-induced B cell phenotype through LMP2A modulation of TRAF2 may be a pathway by which LMP2A controls B cell function. These findings identify an advance in the understanding of how Epstein-Barr virus can access the germinal center in vivo, a site critical for both the genesis of immunological memory and of virus-associated tumors.


Assuntos
Linfócitos B/virologia , Herpesvirus Humano 4/fisiologia , Proteínas da Matriz Viral/metabolismo , Latência Viral/fisiologia , Animais , Linfócitos B/metabolismo , Transformação Celular Viral/fisiologia , Centro Germinativo/metabolismo , Centro Germinativo/virologia , Switching de Imunoglobulina/genética , Memória Imunológica/genética , Camundongos , Camundongos Transgênicos , Fenótipo , Fator 2 Associado a Receptor de TNF/genética , Fator 2 Associado a Receptor de TNF/metabolismo , Proteínas da Matriz Viral/genética
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