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1.
Western Pac Surveill Response J ; 15(5 Spec edition): 1-7, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39171201

RESUMO

Objective: The COVID-19 pandemic challenged the Global Outbreak Alert and Response Network's (GOARN) mechanism used to rapidly deploy technical support for international responses and highlighted areas that require strengthened capacity within the Network. GOARN's partners in the World Health Organization's (WHO) South-East Asia and Western Pacific regions were engaged to explore their levels of preparedness, readiness and ability to respond to international public health emergencies. Methods: Consultative discussions were held and a survey was conducted with GOARN's partners from the two WHO regions. Discussion topics included partners' capacity to support and participate in a GOARN deployment, training, research and collaboration. Descriptive and content analyses were conducted. Results: Barriers to engaging in GOARN's international outbreak response efforts included limited numbers of personnel trained to respond to outbreaks; institutional, financial and administrative hurdles; and limited collaboration opportunities. Partners identified innovative solutions that could strengthen their engagement with deployment, such as financial subsidies, mentorship for less experienced staff, and the ability to provide remote support. Discussion: GOARN plays an important role in enabling WHO to fulfil its international alert and response duties during disease outbreaks and humanitarian crises that have the potential to spark disease outbreaks. Yet without systematic improvement to strengthen national outbreak capacity and regional connectedness, support for international outbreak responses may remain limited. Thus, it is necessary to integrate novel approaches to support international deployments, as identified in this study.


Assuntos
COVID-19 , Surtos de Doenças , Organização Mundial da Saúde , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Surtos de Doenças/prevenção & controle , Organização Mundial da Saúde/organização & administração , Sudeste Asiático/epidemiologia , SARS-CoV-2 , Cooperação Internacional , Saúde Global , Fortalecimento Institucional/organização & administração , Pandemias/prevenção & controle , Ilhas do Pacífico/epidemiologia
4.
Western Pac Surveill Response J ; 15(5 Spec edition): 1-6, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952484

RESUMO

Problem: In January 2022, Kiribati experienced widespread community transmission of COVID-19, leading to high rates of infection among health-care workers (HCWs), which reduced essential HCWs during a period of increased hospital admissions. Context: Kiribati, a Pacific island country made up of a remote group of 33 low-lying atolls in the Pacific Ocean, experienced its first surge of COVID-19 cases beginning on 24 January 2022. Action: Reports of increasing numbers of COVID-19 cases in South Tarawa prompted the Kiribati Ministry of Health and Medical Services to request assistance from the international community, including the World Health Organization's Global Outbreak Alert and Response Network (GOARN), to support national COVID-19 response operations. Specialists in infection prevention and control (IPC) were deployed to Kiribati in February 2022 to assist the Ministry's National COVID-19 Taskforce in collaboration with national partners. These specialists helped review and strengthen IPC capacities to accommodate a potential patient surge and consequent demands for medical consumables in health-care facilities in South Tarawa. Outcome: Strengthened knowledge about and processes for IPC among HCWs prevented health care-associated infections and reduced community disease transmission during the first surge of COVID-19 cases in Kiribati. Discussion: GOARN has the capacity and ability to rapidly deploy experts to support requests for assistance. Outbreak response activities can be enhanced and sustained by using GOARN's resources and collaborating with all partners, as necessary.


Assuntos
COVID-19 , Surtos de Doenças , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/transmissão , Surtos de Doenças/prevenção & controle , Micronésia/epidemiologia , Pessoal de Saúde , Controle de Infecções/organização & administração , Controle de Infecções/métodos
5.
Western Pac Surveill Response J ; 15(5 Spec edition): 1-7, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38510816

RESUMO

Problem: The Global Outbreak Alert and Response Network (GOARN) has responded to more than 100 outbreaks during the past 23 years. The coronavirus disease (COVID-19) pandemic presented unprecedented operational constraints that challenged GOARN's core mission to rapidly deploy technical experts from its partners to support national in-country responses to public health emergencies. This paper describes the type and duration of GOARN deployments to and within the World Health Organization's (WHO's) Western Pacific Region during the COVID-19 pandemic. Context: Despite strict border closures and ever-changing vaccination and quarantine requirements, GOARN continued to deploy international technical assistance to strengthen COVID-19 response operations within the Region, as requested. Action: Data were analysed from the GOARN Knowledge Platform about deployments to and within the Region for responses to the COVID-19 pandemic between 1 January 2020 and 5 May 2023. Data were available about deployment duration, technical role requested, country or area, partner organization and deployed expert's demographics. Feedback from postdeployment briefings with the experts was collected and thematically analysed to determine ongoing needs and gaps to help improve deployment operations. Outcome: There were 72 experts deployed on 89 missions through GOARN to 12 countries and areas in the Region, for a total of 4558 field days, to support the response to the COVID-19 pandemic. Discussion: The volume of requests for assistance from countries and areas in the Region to respond to the COVID-19 pandemic uncovered a deficit in human resources available for domestic response to outbreaks and the reliance on international assistance. Strengthening the in-country capacity of ready-to-respond public health emergency staff is critical to meet the needs for outbreak response. The ongoing demand for technical experts to support national responses means that these lessons may have immediate implications.


Assuntos
COVID-19 , Pandemias , Humanos , Pandemias/prevenção & controle , COVID-19/epidemiologia , COVID-19/prevenção & controle , Surtos de Doenças/prevenção & controle , Saúde Pública , Organização Mundial da Saúde
9.
Lancet Reg Health Am ; 26: 100592, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37727865

RESUMO

In 2013, the SickKids-Caribbean Initiative (SCI) was formalised among The Hospital for Sick Children in Toronto, Canada, the University of the West Indies, and Ministries of Health in six Caribbean countries (Barbados, The Bahamas, Jamaica, St. Lucia, St. Vincent and the Grenadines, and Trinidad and Tobago). The aim was to improve the outcomes and quality of life of children (<18 years) with cancer and blood disorders in the partner countries. Core activities included filling a human resource gap by training paediatric haematologists/oncologists and specialised registered nurses; improving capacity to diagnose and treat diverse haematology/oncology cases; developing and maintaining paediatric oncology databases; creating ongoing advocacy activities with international agencies, decision makers, and civil society; and establishing an integrated administration, management, and funding structure. We describe core program components, successes, and challenges to inform others seeking to improve health service delivery in a multidisciplinary and complex partnership.

10.
Surg Open Sci ; 10: 83-90, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36039075

RESUMO

Background: Clinically useful biomaterials are derived from xenogeneic extracellular matrices, but extensive processes often used to remove all residual DNA are detrimental to their proper biological function. We hypothesized that deliberate and repeated injection of DNA extracted from clinically implantable, xenogeneic extracellular matrices might elicit an immune response in a well-established murine model that could ultimately lead to altered extracellular matrix remodeling. Methods: DNA was purified from unprocessed porcine extracellular matrices and processed extracellular matrices before sterilization (aseptic) and after sterilization. Groups of 10 mice were injected with these 3 purified DNAs and 3 controls: (1) DNA from E. coli; (2) DNA from unprocessed porcine extracellular matrices combined with interleukin-12 and methylated bovine serum albumin and emulsified in incomplete Freund's adjuvant; and (3) buffered saline. Immunizations occurred every 2 weeks for a total of 3 injections. Local cytokines and systemic anti-DNA antibodies were quantified 3 and 7 days after final injection. Results: The DNA extracted from unprocessed, aseptic, or sterilized porcine extracellular matrices failed to elicit a rejection response, and only with significant, proinflammatory adjuvant activation could such a response be seen. Without the adjuvants, biomaterial-derived DNA resulted in a mild accommodation cytokine response locally and no systemic anti-DNA antibody expression even at doses approximately 100-fold larger than would be clinically likely via extracellular matrix implantation. Conclusion: The immunological safety of porcine extracellular matrix biomaterials appears not to be related to DNA residues present. Such biomaterials need not be extensively processed, likely leading to detrimental changes in their bioactivity, solely in an effort to remove the mammalian DNA.

11.
JCI Insight ; 7(11)2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35482422

RESUMO

Secondary infections are frequent complications of viral respiratory infections, but the potential consequence of SARS-CoV-2 coinfection with common pulmonary pathogens is poorly understood. We report that coinfection of human ACE2-transgenic mice with sublethal doses of SARS-CoV-2 and Streptococcus pneumoniae results in synergistic lung inflammation and lethality. Mortality was observed regardless of whether SARS-CoV-2 challenge occurred before or after establishment of sublethal pneumococcal infection. Increased bacterial levels following coinfection were associated with alveolar macrophage depletion, and treatment with murine GM-CSF reduced numbers of lung bacteria and pathology and partially protected from death. However, therapeutic targeting of IFNs, an approach that is effective against influenza coinfections, failed to increase survival. Combined vaccination against both SARS-CoV-2 and pneumococci resulted in 100% protection against subsequent coinfection. The results indicate that when seasonal respiratory infections return to prepandemic levels, they could lead to an increased incidence of lethal COVID-19 superinfections, especially among the unvaccinated population.


Assuntos
COVID-19 , Coinfecção , Animais , COVID-19/prevenção & controle , Camundongos , Camundongos Transgênicos , SARS-CoV-2 , Streptococcus pneumoniae , Vacinação
12.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35169077

RESUMO

Functional plasticity of innate lymphoid cells (ILCs) and T cells is regulated by host environmental cues, but the influence of pathogen-derived virulence factors has not been described. We now report the interplay between host interferon (IFN)-γ and viral PB1-F2 virulence protein in regulating the functions of ILC2s and T cells that lead to recovery from influenza virus infection of mice. In the absence of IFN-γ, lung ILC2s from mice challenged with the A/California/04/2009 (CA04) H1N1 virus, containing nonfunctional viral PB1-F2, initiated a robust IL-5 response, which also led to improved tissue integrity and increased survival. Conversely, challenge with Puerto Rico/8/1934 (PR8) H1N1 virus expressing fully functional PB1-F2, suppressed IL-5+ ILC2 responses, and induced a dominant IL-13+ CD8 T cell response, regardless of host IFN-γ expression. IFN-γ-deficient mice had increased survival and improved tissue integrity following challenge with lethal doses of CA04, but not PR8 virus, and increased resistance was dependent on the presence of IFN-γR+ ILC2s. Reverse-engineered influenza viruses differing in functional PB1-F2 activity induced ILC2 and T cell phenotypes similar to the PB1-F2 donor strains, demonstrating the potent role of viral PB1-F2 in host resistance. These results show the ability of a pathogen virulence factor together with host IFN-γ to regulate protective pulmonary immunity during influenza infection.


Assuntos
Linfócitos/imunologia , Orthomyxoviridae/metabolismo , Proteínas Virais/metabolismo , Animais , Feminino , Imunidade Inata/imunologia , Interferon gama/metabolismo , Interferons/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Pulmão/metabolismo , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Orthomyxoviridae/patogenicidade , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/metabolismo , Proteínas Virais/fisiologia , Virulência/genética , Fatores de Virulência/genética , Replicação Viral/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-36817503

RESUMO

Problem: Rapid response teams (RRTs) are critical for effective responses to acute public health events. While validated training packages and guidance on rolling out training for RRTs are available, they lack country-specific adaptations. Documentation is limited on RRT programming experiences in various contexts. Context: In Papua New Guinea, there remain gaps in implementing standardized, rapid mobilization of multidisciplinary RRTs at the national, provincial and district levels to investigate public health alerts. Action: The human resources needed to respond to the coronavirus disease (COVID-19) pandemic forced a review of the RRT training programme and its delivery. The training model was contextualized and adapted for implementation using a staged approach, with the initiation training phase designed to ensure RRT readiness to deploy immediately in response to COVID-19 and other public health events. Lessons learned: Selecting appropriate trainees and using a phased training approach, incorporating after-training reviews, and between-phase support from the national programme team were found to be important for programme design in Papua New Guinea. Using participatory training methods based on principles of adult learning, in which trainees draw on their own experiences, was integral to building confidence among team members in conducting outbreak investigations. Discussion: The RRT training experience in Papua New Guinea has highlighted the importance of codeveloping and delivering a context-specific training programme to meet a country's unique needs. A staged training approach that builds on knowledge and skills over time, used together with ongoing follow-up and support in the provinces, has been critical in operationalizing ready-to-respond RRTs.


Assuntos
COVID-19 , Equipe de Respostas Rápidas de Hospitais , Adulto , Humanos , Pandemias , Papua Nova Guiné , Surtos de Doenças
14.
Lancet Glob Health ; 9(9): e1314-e1324, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34416215

RESUMO

BACKGROUND: Equitable access to essential medicines is a key facet of childhood cancer care, recognised by WHO as vital to improved childhood cancer outcomes globally. In the Caribbean, childhood cancer outcomes are poorer than those in most high-income countries. We aimed to generate in-depth comparative evidence of the current challenges and opportunities related to access to childhood cancer medicines in the Caribbean to identify context-sensitive health systems strategies to improve drug access and inform evidence-based paediatric cancer policies in the region. METHODS: In this convergent, parallel, mixed-methods study, we mapped and analysed the determinants of access to childhood cancer medicines in four Caribbean countries (The Bahamas, Barbados, Jamaica, and Trinidad and Tobago). We analysed contextual determinants of access to medicines within and across study site jurisdictions, alignment of childhood cancer medicine inclusion between each country's national essential medicines list (NEML) and WHO's 2017 Essential Medicines List for Children, and availability and cost of chemotherapeutic agents at five tertiary care hospitals. We used a mixed-effects logistic regression model to analyse the association of medicine price, procurement efficiency (via median price ratio [MPR]), and site with drug availability. The fixed effect evaluated the effect of site and MPR on the probability of stockout in a given month. We assessed determinants of medicine access via thematic analysis of semi-structured qualitative interviews, literature, and policy documents. FINDINGS: We collected and analysed data for 28 childhood cancer medicines from Barbados, 32 from The Bahamas, 30 from Trinidad and Tobago, and 31 from Jamaica. Despite stepwise inclusion of childhood cancer medicines in NEMLs, all four countries had frequent and recurrent stockouts for many cytotoxic medicines, showing no consistent relationship between NEML inclusion and availability. A mean MPR of greater than 3·0 in Trinidad and Tobago, The Bahamas, and Barbados suggests uniformly high procurement inefficiency, resulting in significant effects on drug stockout days. For each one unit increase in MPR the adjusted odds ratio (OR) of stockout increased by 10% (adjusted OR 1·10, 95% CI 1·04-1·16; p<0·01). These challenges in access to childhood cancer medicines stem from health system and policy dynamics at institutional, national, and supranational levels that cause price volatility and erratic medicine availability. Key challenges include disparate policy commitments (eg, among sites), inefficient procurement and supply chain management practices, and local effects of international market pressures. INTERPRETATION: The Caribbean region exemplifies deficiencies in access to childhood cancer medicines that might be overcome by improved regional harmonisation of drug registration, pharmacovigilance, and procurement alongside national forecasting to strengthen global pharmaceutical planning and prioritisation. Focused political attention to address these challenges is required to ensure efficient, reliable, and sustained availability of cancer mediciness. FUNDING: The SickKids-Caribbean Initiative.


Assuntos
Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Neoplasias/tratamento farmacológico , Região do Caribe , Criança , Humanos , Pesquisa Qualitativa
15.
PLoS One ; 16(7): e0254852, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34292998

RESUMO

BACKGROUND: Methicillin-Resistant Staphylococcus aureus (MRSA) is endemic in hospitals worldwide. Intrahospital transfers may impact MRSA acquisition risk experienced by patients. In this study, we investigated ward characteristics and connectivity that are associated with MRSA acquisition. METHODS: We analysed electronic medical records on patient transfers and MRSA screening of in-patients at an acute-care tertiary hospital in Singapore to investigate whether ward characteristics and connectivity within a network of in-patient wards were associated with MRSA acquisition rates over a period of four years. RESULTS: Most patient transfers concentrated in a stable core network of wards. Factors associated with increased rate of MRSA acquisition were MRSA prevalence among patients transferred from other wards (rate ratio (RR): 7.74 [95% confidence interval (CI): 3.88, 15.44], additional 5 percentage point), critical care ward (RR: 1.72 [95% CI: 1.09, 2.70]) and presence of MRSA cohorting beds (RR: 1.39 [95% CI: 1.03, 1.90]. Oncology ward (RR: 0.66 [95% CI: 0.46, 0.94]) (compared to medical ward), and median length of stay (RR: 0.70 [95% CI: 0.55, 0.90], additional 1.5 days) were associated with lower acquisition rates. In addition, we found evidence of interaction between MRSA prevalence among patients transferred from other wards and weighted in-degree although the latter was not associated with MRSA acquisition after controlling for confounders. CONCLUSION: Wards with higher MRSA prevalence among patients transferred from other wards were more likely to have higher MRSA acquisition rate. Its effect further increased in wards receiving greater number of patients. In addition, critical care ward, presence of MRSA cohorting beds, ward specialty, and median length of stay were associated with MRSA acquisition.


Assuntos
Registros Eletrônicos de Saúde , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas/epidemiologia , Centros de Atenção Terciária , Adulto , Feminino , Humanos , Doença Iatrogênica/epidemiologia , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Pessoa de Meia-Idade , Prevalência , Singapura/epidemiologia
16.
BMC Med ; 19(1): 123, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33985496

RESUMO

For 20 years, the Global Outbreak Response and Alert Network (GOARN) has been a leader in the coordination of international outbreak response. On the premise that no single institution can provide all capacities required to successfully respond to a complex public health emergency or fulfil all outbreak response training needs, GOARN embarked on a capacity building journey that draws on the unique strengths of more than 250 partner institutions. Through extensive engagement and collaboration, GOARN Partners have created a bespoke, multifaceted, 3-tiered training programme which has evolved over the last 15 years and enhanced the competencies of thousands of multidisciplinary outbreak responders around the world.


Assuntos
Surtos de Doenças , Saúde Pública , Surtos de Doenças/prevenção & controle , Saúde Global , Humanos
17.
PLoS Pathog ; 17(3): e1009405, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33690728

RESUMO

Bacterial co-infections represent a major clinical complication of influenza. Host-derived interferon (IFN) increases susceptibility to bacterial infections following influenza, but the relative roles of type-I versus type-II IFN remain poorly understood. We have used novel mouse models of co-infection in which colonizing pneumococci were inoculated into the upper respiratory tract; subsequent sublethal influenza virus infection caused the bacteria to enter the lungs and mediate lethal disease. Compared to wild-type mice or mice deficient in only one pathway, mice lacking both IFN pathways demonstrated the least amount of lung tissue damage and mortality following pneumococcal-influenza virus superinfection. Therapeutic neutralization of both type-I and type-II IFN pathways similarly provided optimal protection to co-infected wild-type mice. The most effective treatment regimen was staggered neutralization of the type-I IFN pathway early during co-infection combined with later neutralization of type-II IFN, which was consistent with the expression and reported activities of these IFNs during superinfection. These results are the first to directly compare the activities of type-I and type-II IFN during superinfection and provide new insights into potential host-directed targets for treatment of secondary bacterial infections during influenza.


Assuntos
Coinfecção/imunologia , Interferons/imunologia , Infecções por Orthomyxoviridae/imunologia , Pneumonia Pneumocócica/imunologia , Superinfecção/imunologia , Animais , Suscetibilidade a Doenças , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transdução de Sinais/imunologia
18.
FEBS Lett ; 594(17): 2782-2799, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32484234

RESUMO

Intracellular pathogens affect diverse host cellular defence and metabolic pathways. Here, we used infection with Francisella tularensis to identify SON DNA-binding protein as a central determinant of macrophage activities. RNAi knockdown of SON increases survival of human macrophages following F. tularensis infection or inflammasome stimulation. SON is required for macrophage autophagy, interferon response factor 3 expression, type I interferon response and inflammasome-associated readouts. SON knockdown has gene- and stimulus-specific effects on inflammatory gene expression. SON is required for accurate splicing and expression of GBF1, a key mediator of cis-Golgi structure and function. Chemical GBF1 inhibition has similar effects to SON knockdown, suggesting that SON controls macrophage functions at least in part by controlling Golgi-associated processes.


Assuntos
Autofagia/genética , Proteínas de Ligação a DNA/genética , Francisella tularensis/patogenicidade , Complexo de Golgi/imunologia , Fatores de Troca do Nucleotídeo Guanina/genética , Interações Hospedeiro-Patógeno/genética , Macrófagos/imunologia , Antígenos de Histocompatibilidade Menor/genética , Autofagia/efeitos dos fármacos , Morte Celular , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/imunologia , Francisella tularensis/genética , Francisella tularensis/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Complexo de Golgi/metabolismo , Complexo de Golgi/microbiologia , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Fatores de Troca do Nucleotídeo Guanina/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Antígenos de Histocompatibilidade Menor/imunologia , Piridinas/farmacologia , Quinolinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Células THP-1 , Acetato de Tetradecanoilforbol/farmacologia
19.
Vaccines (Basel) ; 7(4)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614565

RESUMO

Secondary bacterial pneumonia is responsible for significant morbidity and mortality during seasonal and pandemic influenza. Due to the unpredictability of influenza A virus evolution and the time-consuming process of manufacturing strain-specific influenza vaccines, recent efforts have been focused on developing anti-Streptococcus pneumoniae immunity to prevent influenza-related illness and death. Bacterial vaccination to prevent viral-bacterial synergistic interaction during co-infection is a promising concept that needs further investigation. Here, we show that immunization with pneumococcal surface protein A (PspA) fully protects mice against low-dose, but not high-dose, secondary bacterial challenge using a murine model of influenza A virus-S. pneumoniae co-infection. We further show that immunization with PspA is more broadly protective than the pneumococcal conjugate vaccine (Prevnar). These results demonstrate that PspA is a promising vaccine target that can provide protection against a physiologically relevant dose of S. pneumoniae following influenza infection.

20.
mBio ; 10(4)2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266877

RESUMO

Fatal outcomes following influenza infection are often associated with secondary bacterial infections. Allergic airway disease (AAD) is known to influence severe complications from respiratory infections, and yet the mechanistic effect of AAD on influenza virus-Streptococcus pneumoniae coinfection has not been investigated previously. We examined the impact of AAD on host susceptibility to viral-bacterial coinfections. We report that AAD improved survival during coinfection when viral-bacterial challenge occurred 1 week after AAD. Counterintuitively, mice with AAD had significantly deceased proinflammatory responses during infection. Specifically, both CD4+ and CD8+ T cell interferon gamma (IFN-γ) responses were suppressed following AAD. Resistance to coinfection was also associated with strong transforming growth factor ß1 (TGF-ß1) expression and increased bacterial clearance. Treatment of AAD mice with IFN-γ or genetic deletion of TGF-ß receptor II expression reversed the protective effects of AAD. Using a novel triple-challenge model system, we show for the first time that AAD can provide protection against influenza virus-S. pneumoniae coinfection through the production of TGF-ß that suppresses the influenza virus-induced IFN-γ response, thereby preserving antibacterial immunity.IMPORTANCE Asthma has become one of the most common chronic diseases and has been identified as a risk factor for developing influenza. However, the impact of asthma on postinfluenza secondary bacterial infection is currently not known. Here, we developed a novel triple-challenge model of allergic airway disease, primary influenza infection, and secondary Streptococcus pneumoniae infection to investigate the impact of asthma on susceptibility to viral-bacterial coinfections. We report for the first time that mice recovering from acute allergic airway disease are highly resistant to influenza-pneumococcal coinfection and that this resistance is due to inhibition of influenza virus-mediated impairment of bacterial clearance. Further characterization of allergic airway disease-associated resistance against postinfluenza secondary bacterial infection may aid in the development of prophylactic and/or therapeutic treatment against coinfection.


Assuntos
Asma/complicações , Coinfecção/imunologia , Coinfecção/patologia , Suscetibilidade a Doenças , Influenza Humana/imunologia , Influenza Humana/patologia , Infecções Pneumocócicas/patologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Humanos , Vírus da Influenza A/crescimento & desenvolvimento , Interferon gama/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Infecções Pneumocócicas/imunologia , Streptococcus pneumoniae/crescimento & desenvolvimento , Análise de Sobrevida , Fator de Crescimento Transformador beta/metabolismo
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