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1.
J Zoo Wildl Med ; 55(1): 212-218, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38453505

RESUMEN

Improved methods are needed to prevent wildlife deaths from anthrax. Caused by Bacillus anthracis, naturally occurring outbreaks of anthrax are frequent but unpredictable. The commercially available veterinary vaccine is labeled for subcutaneous injection and is impractical for large-scale wildlife vaccination programs; therefore, oral vaccination is the most realistic method to control and prevent these outbreaks. We reported the induction of an anthrax-specific lethal toxin (LeTx) neutralizing antibody response in mice following oral vaccination with alginate microcapsules containing B. anthracis Sterne strain 34F2 spores, coated with poly-L-lysine (PLL) and vitelline protein B (VpB). We continued evaluating our novel vaccine formulation through this proof-of-concept study in white-tailed deer (WTD; Odocoileus virginianus; n = 9). We orally vaccinated WTD via needle-free syringe with three formulations of the encapsulated vaccine: 1) PLL-VpB-coated microcapsules with 107-8 spores/ml (n = 5), 2) PLL-VpB-coated microcapsules with 109-10 spores/ml (n = 2), and 3) PLL-coated microcapsules with 109-10 spores/ml (n = 2). Although the limited sample sizes require continued experimentation, we observed an anthrax-specific antibody response in WTD serum following oral vaccination with PLL-coated microcapsules containing 109 spores/ ml. Furthermore, this antibody response neutralized anthrax LeTx in vitro, suggesting that continued development of this vaccine may allow for realistic wildlife anthrax vaccination programs.


Asunto(s)
Vacunas contra el Carbunco , Carbunco , Bacillus anthracis , Ciervos , Enfermedades de los Roedores , Animales , Ratones , Carbunco/prevención & control , Carbunco/veterinaria , Anticuerpos Neutralizantes , Cápsulas , Espectroscopía de Resonancia por Spin del Electrón/veterinaria , Vacunación/veterinaria , Animales Salvajes , Anticuerpos Antibacterianos
2.
J Wildl Dis ; 60(1): 179-183, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37921658

RESUMEN

Outbreaks of anthrax, caused by the soilborne bacterium Bacillus anthracis, are a continuous threat to free-ranging livestock and wildlife in enzootic regions of the United States, sometimes causing mass mortalities. Injectable anthrax vaccines are commercially available for use in livestock, and although hand injection is not a cost- or time-effective long-term management plan for prevention in wildlife, it may provide a tool for managers to target selectively animals of high conservation or economic value. Vaccine-induced anthrax-specific antibody responses have been reported previously in white-tailed deer (Odocoileus virginianus), but the protective nature was not determined. In this study, five white-tailed deer were subcutaneously vaccinated with one dose (1 mL) of the Anthrax Spore Vaccine. Eight blood collections by jugular venipuncture were conducted over 146 d to measure the anthrax-specific antibody response in each deer's serum over time. Antibodies were first detected by ELISA and later with toxin neutralization assays to estimate in vitro protection. Average peak absorbance by ELISA occurred at 14 d postvaccination, whereas average peak in vitro protection occurred at 28 d postvaccination. Observed in vitro protection on average for white-tailed deer after this single-dose vaccination protocol lasted 42-56 d postvaccination, although three individuals still maintained lethal toxin-neutralizing serum antibody titers out to 112 d postvaccination. Vaccination responses were variable but effective to some degree in all white-tailed deer.


Asunto(s)
Vacunas contra el Carbunco , Carbunco , Bacillus anthracis , Ciervos , Humanos , Animales , Carbunco/prevención & control , Carbunco/veterinaria , Carbunco/epidemiología , Ciervos/microbiología , Esporas Bacterianas , Animales Salvajes/microbiología , Vacunación/veterinaria , Anticuerpos Neutralizantes , Anticuerpos Antibacterianos , Antígenos Bacterianos
3.
Elife ; 112022 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-35587649

RESUMEN

The phagocytosis and destruction of pathogens in lysosomes constitute central elements of innate immune defense. Here, we show that Brucella, the causative agent of brucellosis, the most prevalent bacterial zoonosis globally, subverts this immune defense pathway by activating regulated IRE1α-dependent decay (RIDD) of Bloc1s1 mRNA encoding BLOS1, a protein that promotes endosome-lysosome fusion. RIDD-deficient cells and mice harboring a RIDD-incompetent variant of IRE1α were resistant to infection. Inactivation of the Bloc1s1 gene impaired the ability to assemble BLOC-1-related complex (BORC), resulting in differential recruitment of BORC-related lysosome trafficking components, perinuclear trafficking of Brucella-containing vacuoles (BCVs), and enhanced susceptibility to infection. The RIDD-resistant Bloc1s1 variant maintains the integrity of BORC and a higher-level association of BORC-related components that promote centrifugal lysosome trafficking, resulting in enhanced BCV peripheral trafficking and lysosomal destruction, and resistance to infection. These findings demonstrate that host RIDD activity on BLOS1 regulates Brucella intracellular parasitism by disrupting BORC-directed lysosomal trafficking. Notably, coronavirus murine hepatitis virus also subverted the RIDD-BLOS1 axis to promote intracellular replication. Our work establishes BLOS1 as a novel immune defense factor whose activity is hijacked by diverse pathogens.


Asunto(s)
Brucella , Brucelosis , Animales , Brucelosis/metabolismo , Brucelosis/microbiología , Endorribonucleasas/metabolismo , Endosomas/metabolismo , Ratones , Proteínas Serina-Treonina Quinasas
4.
Am J Trop Med Hyg ; 105(5): 1227-1229, 2021 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-34544043

RESUMEN

To better understand the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant lineage distribution in a college campus population, we carried out viral genome surveillance over a 7-week period from January to March 2021. Among the sequences were three novel viral variants: BV-1 with a B.1.1.7/20I genetic background and an additional spike mutation Q493R, associated with a mild but longer-than-usual COVID-19 case in a college-age person, BV-2 with a T478K mutation on a 20B genetic background, and BV-3, an apparent recombinant lineage. This work highlights the potential of an undervaccinated younger population as a reservoir for the spread and generation of novel variants. This also demonstrates the value of whole genome sequencing as a routine disease surveillance tool.


Asunto(s)
COVID-19/virología , Reservorios de Enfermedades/virología , Mutación , SARS-CoV-2/genética , Estudiantes/estadística & datos numéricos , Universidades , Adulto , COVID-19/etiología , Genoma Viral , Humanos , Pruebas de Neutralización , SARS-CoV-2/inmunología , SARS-CoV-2/aislamiento & purificación , Adulto Joven
6.
iScience ; 24(3): 102192, 2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33718841

RESUMEN

Phagocytosis and autophagy play critical roles in immune defense. The human fungal pathogen Cryptococcus neoformans (Cn) subverts host autophagy-initiation complex (AIC)-related proteins, to promote its phagocytosis and intracellular parasitism of host cells. The mechanisms by which the pathogen engages host AIC-related proteins remain obscure. Here, we show that the recruitment of host AIC proteins to forming phagosomes is dependent upon the activity of CD44, a host cell surface receptor that engages fungal hyaluronic acid (HA). This interaction elevates intracellular Ca2+ concentrations and activates CaMKKß and its downstream target AMPKα, which results in activation of ULK1 and the recruitment of AIC components. Moreover, we demonstrate that HA-coated beads efficiently recruit AIC components to phagosomes and CD44 interacts with AIC components. Taken together, these findings show that fungal HA plays a critical role in directing the internalization and productive intracellular membrane trafficking of a fungal pathogen of global importance.

7.
Vaccine ; 39(3): 617-625, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33328142

RESUMEN

Small ruminant brucellosis is caused by the Gram negative cocci-bacillus Brucella (B.) melitensis, the most virulent Brucella species for humans. In goats and sheep, middle to late-term gestation abortion, stillbirths and the delivery of weak infected offspring are the characteristic clinical signs of the disease. Vaccination with the currently available Rev. 1 vaccine is the best option to prevent and control the disease, although it is far from ideal. In this study, we investigate the safety of the B. melitensis 16MΔvjbR strain during a 15-month period beginning at vaccination of young goats, impregnation, delivery and lactation. Forty, 4 to 6 months old, healthy female crossbreed goats were randomly divided into four groups (n = 10) and immunized subcutaneously with a single vaccine dose containing 1x109 CFU of B. melitensis 16MΔvjbR delivered in alginate microcapsules or non-encapsulated. Controls received empty capsules or the commercially available Rev.1 vaccine. Seven months post-vaccination, when animals were sexually mature, all goats were naturally bred using brucellosis-free males, and allowed to carry pregnancies to term. Blood samples to assess the humoral immune response were collected throughout the study. At two months post-delivery, all dams and their offspring were euthanized and a necropsy was performed to collect samples for bacteriology and histology. Interestingly, none of the animals that received the vaccine candidate regardless of the formulation exhibited any clinical signs associated with vaccination nor shed the vaccine strain through saliva, vagina or the milk. Gross and histopathologic changes in all nannies and offspring were unremarkable with no evidence of tissue colonization or vertical transmission to fetuses. Altogether, these data demonstrate that vaccination with the mutant strain 16MΔvjbR is safe for use in the non-pregnant primary host.


Asunto(s)
Vacuna contra la Brucelosis , Brucella melitensis , Brucelosis , Enfermedades de las Ovejas , Animales , Brucelosis/prevención & control , Brucelosis/veterinaria , Femenino , Cabras , Humanos , Embarazo , Ovinos
8.
Microbiol Immunol ; 64(11): 730-736, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32965738

RESUMEN

Brucellosis is a major zoonotic disease, and Brucella melitensis is the species most often associated with human infection. Vaccination is the most efficient tool for controlling animal brucellosis, with a consequent decrease of incidence of human infections. Commercially available live attenuated vaccines provide some degree of protection, but retain residual pathogenicity to human and animals. In this study, Brucella ovis ∆abcBA (Bo∆abcBA), a live attenuated candidate vaccine strain, was tested in two formulations (encapsulated with alginate and alginate plus vitelline protein B [VpB]) to immunize mice against experimental challenge with B. melitensis strain 16M. One week after infection, livers and spleens of immunized mice had reduced numbers of the challenge strain B. melitensis 16M when compared with those of nonimmunized mice, with a reduction of approximately 1-log10 of B. melitensis 16M count in the spleens from immunized mice. Moreover, splenocytes stimulated with B. melitensis antigens in vitro secreted IFN-γ when mice had been immunized with Bo∆abcBA encapsulated with alginate plus VpB, but not with alginate alone. Body and liver weights were similar among groups, although spleens from mice immunized with Bo∆abcBA encapsulated with alginate were larger than those immunized with Bo∆abcBA encapsulated with alginate plus VpB or nonimmunized mice. This study demonstrated that two vaccine formulations containing Bo∆abcBA protected mice against experimental challenge with B. melitensis.


Asunto(s)
Vacuna contra la Brucelosis/inmunología , Brucella melitensis/inmunología , Brucella ovis/inmunología , Brucelosis/inmunología , Brucelosis/prevención & control , Animales , Citocinas , Modelos Animales de Enfermedad , Femenino , Inmunización , Hígado/inmunología , Ratones , Ratones Endogámicos BALB C , Bazo/inmunología , Vacunación , Vacunas Atenuadas/inmunología
9.
NPJ Vaccines ; 5: 59, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32685200

RESUMEN

An oral vaccine against anthrax (Bacillus anthracis) is urgently needed to prevent annual anthrax outbreaks that are causing catastrophic losses in free-ranging livestock and wildlife worldwide. The Sterne vaccine, the current injectable livestock vaccine, is a suspension of live attenuated B. anthracis Sterne strain 34F2 spores (Sterne spores) in saponin. It is not effective when administered orally and individual subcutaneous injections are not a practical method of vaccination for wildlife. In this study, we report the development of a microencapsulated oral vaccine against anthrax. Evaluating Sterne spore stability at varying pH's in vitro revealed that spore exposure to pH 2 results in spore death, confirming that protection from the gastric environment is of main concern when producing an oral vaccine. Therefore, Sterne spores were encapsulated in alginate and coated with a protein shell containing poly-L-lysine (PLL) and vitelline protein B (VpB), a non-immunogenic, proteolysis resistant protein isolated from Fasciola hepatica. Capsule exposure to pH 2 demonstrated enhanced acid gel character suggesting that alginate microcapsules provided the necessary protection for spores to survive the gastric environment. Post vaccination IgG levels in BALBc/J mouse serum samples indicated that encapsulated spores induced anti-anthrax specific responses in both the subcutaneous and the oral vaccination groups. Furthermore, the antibody responses from both vaccination routes were protective against anthrax lethal toxin in vitro, suggesting that further optimization of this vaccine formulation may result in a reliable oral vaccine that will conveniently and effectively prevent anthrax in wildlife populations.

10.
Artículo en Inglés | MEDLINE | ID: mdl-32528902

RESUMEN

Acinetobacter baumannii is an important causative agent of nosocomial infections worldwide. The pathogen also readily acquires resistance to antibiotics, and pan-resistant strains have been reported. A. baumannii is widely regarded as an extracellular bacterial pathogen. However, accumulating evidence demonstrates that the pathogen can invade, survive or persist in infected mammalian cells. Unfortunately, the molecular mechanisms controlling these processes remain poorly understood. Here, we show that Drosophila S2 cells provide several attractive advantages as a model system for investigating the intracellular lifestyle of the pathogen, including susceptibility to bacterial intracellular replication and limited infection-induced host cell death. We also show that the Drosophila system can be used to rapidly identify host factors, including MAP kinase proteins, which confer susceptibility to intracellular parasitism. Finally, analysis of the Drosophila system suggested that host proteins that regulate organelle biogenesis and membrane trafficking contribute to regulating the intracellular lifestyle of the pathogen. Taken together, these findings establish a novel model system for elucidating interactions between A. baumannii and host cells, define new factors that regulate bacterial invasion or intracellular persistence, and identify subcellular compartments in host cells that interact with the pathogen.


Asunto(s)
Acinetobacter baumannii , Infección Hospitalaria , Acinetobacter baumannii/genética , Animales , Antibacterianos , Drosophila
11.
Front Public Health ; 8: 76, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32232023

RESUMEN

Background: The scientific evidence of the health risks associated with the consumption of raw milk has been known for a long time. However, less clear is the impact of acquiring infectious diseases from raw milk consumption in the United States (US) due to incomplete reporting of cases and the complex factors associated with the sale and consumption of raw milk. Investigations of this current study focused on human brucellosis, one of the infectious diseases commonly acquired through the consumption of raw milk and milk products, and which continues to be a public health threat worldwide. Methodology: A qualitative systematic review of the sources of opinions that contribute to the increased trend of raw milk sales and consumption in the US was conducted. Results: Interestingly, opinions about the sale of raw milk and/or the benefits arising from its consumption varied by US region, with the proportion of messages supporting raw milk consumption being highest in the Northeast compared to other US regions. Several evidence gaps and factors that possibly contribute to the increased prevalence of raw milk-acquired brucellosis were identified including inadequate monitoring of the raw milk sales process and lack of approved diagnostic methods for validating the safety of raw milk for human consumption. Conclusions: The unavailability of data specifying brucellosis cases acquired from raw milk consumption have precluded the direct association between raw milk and increased brucellosis prevalence in the United States. Nevertheless, the evidence gaps identified in this study demonstrate the need for intensified surveillance of raw-milk acquired infectious diseases including human brucellosis; establishment of safety and quality control measures for the process of selling raw milk; and design of an effective strategy for the prevention of raw milk-acquired infectious diseases including brucellosis. Overall, for the first time, this study has not only shown the gaps in evidence that require future investigations, but also, variations in the perception of raw milk consumption that may impact disease acquisition in different US regions.


Asunto(s)
Brucelosis , Leche , Animales , Brucelosis/epidemiología , Comercio , Humanos , Prevalencia , Salud Pública , Estados Unidos/epidemiología
13.
Vaccine X ; 3: 100041, 2019 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-31528851

RESUMEN

Brucellosis in swine is caused by Brucella suis, a bacterial infection of nearly worldwide distribution. Brucella suis is also transmissible to humans, dogs and cattle and is considered a reemerging disease of public health concern. To date, there is no effective vaccine for swine. This prompted us to investigate the potential use of the commercially available vaccine for cattle or the live attenuated vaccine candidate S19ΔvjbR. As the first step, we sought to study the safety of the vaccine candidates when administered in pregnant sows, since one of the major drawbacks associated with vaccination using Live Attenuated Vaccines (LAV) is the induction of abortions when administered in pregnant animals. Fifteen pregnant gilts at mid-gestation were divided into four groups and subsequently vaccinated subcutaneously using different formulations containing 2.0 ±â€¯0.508 × 109 CFU of either S19 or S19ΔvjbR. Vaccination in pregnant animals with the vaccine candidates did not induce abortion, stillbirths or a reduction in litter size. Multiple tissues in the gilts and piglets were examined at the time of delivery to assess bacterial colonization and histopathological changes. There was no evidence of vaccine persistence in the gilts or bacterial colonization in the fetuses. Altogether, these data suggest that both vaccine candidates are safe for use in pregnant swine. Analysis of the humoral responses, specifically anti-Brucella IgG levels measured in serum, demonstrated a robust response induced by either vaccine, but of shorter duration (4-6 weeks post-inoculation) compared to that observed in cattle or experimentally infected mice. Such a transient humoral response may prove to be beneficial in cases where the vaccine is used in eradication campaigns and in the differentiation of vaccinated from infected animals. This study provides evidence to support future efficacy studies of both vaccine candidates in swine.

14.
Reprod Health ; 16(Suppl 1): 57, 2019 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-31138222

RESUMEN

BACKGROUND: Extensive documentation exists on a range of negative sexual and reproductive health outcomes and rights violations occurring during humanitarian emergencies. We explore two central questions: Do existing policies, services, and research adequately address the SRH rights, priorities and HIV risks of adolescent girls and young women in emergency settings? What are the missed opportunities for holistically addressing the vulnerabilities experienced by those living with HIV during rapid onset disasters and long term, protracted emergencies? Authors review considerations informing real-time decision making, and highlight missed opportunities to apply a gendered lens in the delivery of AGYW-centered SRHR/HIV services. METHODS: A scoping review identified studies on HIV intervention and outcomes in emergency settings, published in the peer-reviewed literature (2002-2017). This exercise was complemented with a desk review of normative guidance, frameworks, and implementation guidelines on HIV and SRH in emergency responses, and by consultations with subject matter experts. RESULTS: The existing frameworks and guidance pay scant attention to the sexual reproductive health and rights of young women living with HIV (WLHIV), focusing mainly on prevention of mother to child transmission (PMTCT), antiretroviral therapy (ART), HIV testing services, and linkage to treatment services. Applying a gendered sexual and reproductive health lens to the response offers opportunities to identify critical implementation questions, and highlight promising practices, to better tailor current services for AGYW. CONCLUSIONS: A plurality of competing needs crowds out dedicated time and space to effectively integrate HIV and sexual and reproductive health interventions in emergency settings. Political will is required to advance multi-sectoral cooperation, through joint planning, rights-informed learning and integrative responses, and to promote creative solutions for ART continuation, drug supply and HIV testing, treatment and care. Recent advancements in policy and practice would suggest that a more AGYW-centered response is feasible.


Asunto(s)
Servicios de Salud del Adolescente/organización & administración , Infecciones por VIH/prevención & control , Política de Salud , Servicios de Salud Reproductiva/organización & administración , Derechos Sexuales y Reproductivos/legislación & jurisprudencia , Derechos Sexuales y Reproductivos/normas , Salud Sexual , Adolescente , Adulto , Femenino , VIH/aislamiento & purificación , Infecciones por VIH/virología , Necesidades y Demandas de Servicios de Salud , Humanos , Metaanálisis como Asunto , Embarazo , Conducta Sexual , Adulto Joven
15.
AIDS ; 32(14): 1913-1915, 2018 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-30005005

RESUMEN

: Motherhood is common among female sex workers (FSWs) and many have at least one biological child. Preventable mother-to-child transmission of HIV can occur given poor uptake of contraception coupled with high rates of unintended pregnancies among FSWs. Globally, there are 2.1 million children living with HIV, and antiretroviral treatment coverage is dismally low at 43%. Without timely diagnosis and treatment, half of all children born with HIV will die by the age of 2 years. By integrating services for key populations and their children, prevention of mother-to-child transmission of HIV uptake among FSW mothers and early infant diagnosis can improve and therefore reduce transmission of HIV. This field note addresses the needs of FSWs and their children, and advocates for programs to develop and scale up comprehensive, integrated, stigma-free services for this vulnerable population. Sensitive, confidential, child-friendly, tailored services that protect FSWs while addressing their children are essential to saving these young lives and breaking the transmission cycle of the virus. By siloing programs that neglect children of FSWs, we are missing opportunities and existing entry points to take an innovative, holistic, family approach to care, support, and treatment services that could improve outcomes. Given the high prevalence of HIV in FSWs and other stigmatizing factors which affect access to services, children of FSWs can no longer afford to be left behind and the time is now to prioritize them in current and future HIV programming.


Asunto(s)
Control de Enfermedades Transmisibles/métodos , Manejo de la Enfermedad , Infecciones por VIH/prevención & control , Infecciones por VIH/transmisión , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Trabajadores Sexuales , Niño , Preescolar , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Humanos , Lactante , Embarazo , Complicaciones Infecciosas del Embarazo/diagnóstico
16.
J Acquir Immune Defic Syndr ; 78 Suppl 2: S128-S133, 2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29994835

RESUMEN

In August 2014, PEPFAR and the Children's Investment Fund Foundation launched the Accelerating Children's HIV/AIDS Treatment (ACT) initiative with the aim of doubling the number of children on antiretroviral treatment in 9 African countries. Increasing rates of pretreatment drug resistance and use of suboptimal treatment regimens and formulations result in poor adherence and high rates of viral failure. Supporting adherence and ensuring appropriate treatment monitoring are needed to maximize duration of first-line treatment and enable timely sequencing to subsequent lines of antiretroviral treatment. Although timely antiretroviral treatment is the core of clinical care for infants, children and adolescents living with HIV, ensuring a broader package of biomedical and non-biomedical interventions is also required to address highly prevalent comorbidities among children living with HIV. Providing such a comprehensive package has been challenging for health care workers who lack the necessary skills and confidence to care for pediatric populations. Efforts to simplify clinical management and specific training and mentorship are needed to address these challenges. In this article, we review the progress made during the ACT initiative and the persistent challenges in achieving and maintaining virological suppression across the age spectrum. We identify innovations needed to build on the success of the ACT initiative. Despite the challenges, achieving high levels of virological suppression in children and adolescents is possible. The complexity of pediatric HIV treatment can be offset as antiretroviral regimens become more effective, tolerable, and easier to prescribe and administer. Meanwhile, basic programmatic elements to address comorbidities as well as support health care workers remain critical. In this article we review the progress made through the ACT initiative, as well as identify innovations needed to address persistent challenges to viral suppression across the age spectrum.


Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Adolescente , Niño , Humanos , Lactante , Cumplimiento de la Medicación , Carga Viral
17.
Artículo en Inglés | MEDLINE | ID: mdl-29732320

RESUMEN

Brucella spp. are intracellular vacuolar pathogens that causes brucellosis, a worldwide zoonosis of profound importance. We previously demonstrated that the activity of host unfolded protein response (UPR) sensor IRE1α (inositol-requiring enzyme 1) and ER-associated autophagy confer susceptibility to Brucella melitensis and Brucella abortus intracellular replication. However, the mechanism by which host IRE1α regulates the pathogen intracellular lifestyle remains elusive. In this study, by employing a diverse array of molecular approaches, including biochemical analyses, fluorescence microscopy imaging, and infection assays using primary cells derived from Ern1 (encoding IRE1) conditional knockout mice, we address this gap in our understanding by demonstrating that a novel IRE1α to ULK1, an important component for autophagy initiation, signaling axis confers susceptibility to Brucella intracellular parasitism. Importantly, deletion or inactivation of key signaling components along this axis, including IRE1α, BAK/BAX, ASK1, and JNK as well as components of the host autophagy system ULK1, Atg9a, and Beclin 1, resulted in striking disruption of Brucella intracellular trafficking and replication. Host kinases in the IRE1α-ULK1 axis, including IRE1α, ASK1, JNK1, and/or AMPKα as well as ULK1, were also coordinately phosphorylated in an IRE1α-dependent fashion upon the pathogen infection. Taken together, our findings demonstrate that the IRE1α-ULK1 signaling axis is subverted by the bacterium to promote intracellular parasitism, and provide new insight into our understanding of the molecular mechanisms of intracellular lifestyle of Brucella.


Asunto(s)
Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Brucella melitensis/patogenicidad , Brucelosis/patología , Endorribonucleasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Autofagia/fisiología , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Proteínas Relacionadas con la Autofagia/genética , Beclina-1/genética , Brucelosis/microbiología , Línea Celular , Drosophila melanogaster , Endorribonucleasas/genética , Interacciones Huésped-Patógeno/fisiología , Proteínas Quinasas JNK Activadas por Mitógenos/genética , MAP Quinasa Quinasa Quinasa 5/genética , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Células RAW 264.7 , Transducción de Señal/fisiología , Respuesta de Proteína Desplegada/fisiología , Proteínas de Transporte Vesicular/genética , Proteína Destructora del Antagonista Homólogo bcl-2/genética , Proteína X Asociada a bcl-2/genética
18.
Cell Host Microbe ; 21(5): 637-649.e6, 2017 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-28494245

RESUMEN

Cryptococcus neoformans (Cn) is a deadly fungal pathogen whose intracellular lifestyle is important for virulence. Host mechanisms controlling fungal phagocytosis and replication remain obscure. Here, we perform a global phosphoproteomic analysis of the host response to Cryptococcus infection. Our analysis reveals numerous and diverse host proteins that are differentially phosphorylated following fungal ingestion by macrophages, thereby indicating global reprogramming of host kinase signaling. Notably, phagocytosis of the pathogen activates the host autophagy initiation complex (AIC) and the upstream regulatory components LKB1 and AMPKα, which regulate autophagy induction through their kinase activities. Deletion of Prkaa1, the gene encoding AMPKα1, in monocytes results in resistance to fungal colonization of mice. Finally, the recruitment of AIC components to nascent Cryptococcus-containing vacuoles (CnCVs) regulates the intracellular trafficking and replication of the pathogen. These findings demonstrate that host AIC regulatory networks confer susceptibility to infection and establish a proteomic resource for elucidating host mechanisms that regulate fungal intracellular parasitism.


Asunto(s)
Criptococosis/inmunología , Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidad , Interacciones Huésped-Patógeno/inmunología , Transducción de Señal/fisiología , Virulencia/genética , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Autofagia/fisiología , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Transporte Biológico/fisiología , Línea Celular , Coxiella burnetii/patogenicidad , Criptococosis/microbiología , Cryptococcus neoformans/crecimiento & desarrollo , Cryptococcus neoformans/metabolismo , Modelos Animales de Enfermedad , Femenino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/fisiología , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones , Ratones Endogámicos C57BL , Monocitos/metabolismo , Fagocitosis , Proteínas Serina-Treonina Quinasas/metabolismo , Proteómica , Células RAW 264.7 , Vacuolas/microbiología , Virulencia/fisiología
19.
PLoS Negl Trop Dis ; 10(8): e0004572, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27537413

RESUMEN

Vaccination of humans and animals with live attenuated organisms has proven to be an effective means of combatting some important infectious diseases. In fact, the 20th century witnessed tremendous improvements in human and animal health worldwide as a consequence of large-scale vaccination programs with live attenuated vaccines (LAVs). Here, we use the neglected zoonotic diseases brucellosis and bovine tuberculosis (BTb) caused by Brucella spp. and Mycobacterium bovis (M. bovis), respectively, as comparative models to outline the merits of LAV platforms with emphasis on molecular strategies that have been pursued to generate LAVs with enhanced vaccine safety and efficacy profiles. Finally, we discuss the prospects of LAV platforms in the fight against brucellosis and BTb and outline new avenues for future research towards developing effective vaccines using LAV platforms.


Asunto(s)
Vacuna contra la Brucelosis , Brucelosis/prevención & control , Enfermedades Desatendidas/prevención & control , Vacunas contra la Tuberculosis , Tuberculosis Bovina/prevención & control , Vacunas Atenuadas , Animales , Brucella/inmunología , Brucella/aislamiento & purificación , Vacuna contra la Brucelosis/efectos adversos , Vacuna contra la Brucelosis/inmunología , Brucelosis/microbiología , Bovinos , Modelos Animales de Enfermedad , Humanos , Ratones , Mycobacterium bovis/inmunología , Mycobacterium bovis/aislamiento & purificación , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/microbiología , Vacunas contra la Tuberculosis/administración & dosificación , Vacunas contra la Tuberculosis/inmunología , Tuberculosis Bovina/microbiología , Vacunación/efectos adversos , Vacunación/métodos , Vacunación/estadística & datos numéricos , Vacunación/tendencias , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/efectos adversos , Vacunas Atenuadas/inmunología , Zoonosis/microbiología , Zoonosis/prevención & control
20.
Am J Pathol ; 185(6): 1505-17, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25892682

RESUMEN

This review of Brucella-host interactions and immunobiology discusses recent discoveries as the basis for pathogenesis-informed rationales to prevent or treat brucellosis. Brucella spp., as animal pathogens, cause human brucellosis, a zoonosis that results in worldwide economic losses, human morbidity, and poverty. Although Brucella spp. infect humans as an incidental host, 500,000 new human infections occur annually, and no patient-friendly treatments or approved human vaccines are reported. Brucellae display strong tissue tropism for lymphoreticular and reproductive systems with an intracellular lifestyle that limits exposure to innate and adaptive immune responses, sequesters the organism from the effects of antibiotics, and drives clinical disease manifestations and pathology. Stealthy brucellae exploit strategies to establish infection, including i) evasion of intracellular destruction by restricting fusion of type IV secretion system-dependent Brucella-containing vacuoles with lysosomal compartments, ii) inhibition of apoptosis of infected mononuclear cells, and iii) prevention of dendritic cell maturation, antigen presentation, and activation of naive T cells, pathogenesis lessons that may be informative for other intracellular pathogens. Data sets of next-generation sequences of Brucella and host time-series global expression fused with proteomics and metabolomics data from in vitro and in vivo experiments now inform interactive cellular pathways and gene regulatory networks enabling full-scale systems biology analysis. The newly identified effector proteins of Brucella may represent targets for improved, safer brucellosis vaccines and therapeutics.


Asunto(s)
Brucella/fisiología , Brucelosis/inmunología , Brucelosis/patología , Interacciones Huésped-Patógeno , Animales , Humanos
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