RESUMEN
Reward processing dysfunctions e.g., anhedonia, apathy, are common in stress-related neuropsychiatric disorders including depression and schizophrenia, and there are currently no established therapies. One potential therapeutic approach is restoration of reward anticipation during appetitive behavior, deficits in which co-occur with attenuated nucleus accumbens (NAc) activity, possibly due to NAc inhibition of mesolimbic dopamine (DA) signaling. Targeting NAc regulation of ventral tegmental area (VTA) DA neuron responsiveness to reward cues could involve either the direct or indirect-via ventral pallidium (VP)-pathways. One candidate is the orphan G protein-coupled receptor GPR52, expressed by DA receptor 2 NAc neurons that project to VP. In mouse brain-slice preparations, GPR52 inverse agonist (GPR52-IA) attenuated evoked inhibitory postsynaptic currents at NAc-VP neurons, which could disinhibit VTA DA neurons. A mouse model in which chronic social stress leads to reduced reward learning and effortful motivation was applied to investigate GPR52-IA behavioral effects. Control and chronically stressed mice underwent a discriminative learning test of tone-appetitive behavior-sucrose reinforcement: stress reduced appetitive responding and discriminative learning, and these anticipatory behaviors were dose-dependently reinstated by GPR52-IA. The same mice then underwent an effortful motivation test of operant behavior-tone-sucrose reinforcement: stress reduced effortful motivation and GPR52-IA dose-dependently restored it. In a new cohort, GRABDA-sensor fibre photometry was used to measure NAc DA activity during the motivation test: in stressed mice, reduced motivation co-occurred with attenuated NAc DA activity specifically to the tone that signaled reinforcement of effortful behavior, and GPR52-IA ameliorated both deficits. These findings: (1) Demonstrate preclinical efficacy of GPR52 inverse agonism for stress-related deficits in reward anticipation during appetitive behavior. (2) Suggest that GPR52-dependent disinhibition of the NAc-VP-VTA-NAc circuit, leading to increased phasic NAc DA signaling of earned incentive stimuli, could account for these clinically relevant effects.
Asunto(s)
Dopamina , Neuronas Dopaminérgicas , Motivación , Núcleo Accumbens , Recompensa , Estrés Psicológico , Animales , Masculino , Ratones , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Dopamina/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Ratones Endogámicos C57BL , Motivación/efectos de los fármacos , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Estrés Psicológico/metabolismo , Área Tegmental Ventral/efectos de los fármacos , Área Tegmental Ventral/metabolismoRESUMEN
Hepatocellular carcinoma (HCC) and solid cancers with liver metastases are indications with high unmet medical need. Interleukin-12 (IL-12) is a proinflammatory cytokine with substantial anti-tumor properties, but its therapeutic potential has not been realized due to severe toxicity. Here, we show that orthotopic liver tumors in mice can be treated by targeting hepatocytes via systemic delivery of adeno-associated virus (AAV) vectors carrying the murine IL-12 gene. Controlled cytokine production was achieved in vivo by using the tetracycline-inducible K19 riboswitch. AAV-mediated expression of IL-12 led to STAT4 phosphorylation, interferon-γ (IFNγ) production, infiltration of T cells and, ultimately, tumor regression. By detailed analyses of efficacy and tolerability in healthy and tumor-bearing animals, we could define a safe and efficacious vector dose. As a potential clinical candidate, we characterized vectors carrying the human IL-12 (huIL-12) gene. In mice, bioactive human IL-12 was expressed in a vector dose-dependent manner and could be induced by tetracycline, suggesting tissue-specific AAV vectors with riboswitch-controlled expression of highly potent proinflammatory cytokines as an attractive approach for vector-based cancer immunotherapy.
Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Riboswitch , Ratones , Humanos , Animales , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/patología , Terapia Genética , Interleucina-12/genética , Interleucina-12/metabolismo , Tetraciclina/farmacologíaRESUMEN
Vectors based on human adenovirus are highly efficient tools for transient genetic modifications of cells or tissues in vitro and in vivo. They can be utilized for gene addition strategies, knockdown strategies and as transfer vectors for designer nucleases and CRISPR/Cas. They are characterized by high genomic stability and can be produced to high titers. This chapter describes the method how to produce, purify and titrate adenovirus vectors based on human adenovirus type 5.
Asunto(s)
Adenoviridae/genética , Vectores Genéticos/genética , Sistemas CRISPR-Cas/genética , Técnicas de Transferencia de GenRESUMEN
Immune defense against hepatotropic viruses such as hepatitis B (HBV) and hepatitis C (HCV) poses a major challenge for therapeutic approaches. Intrahepatic cytotoxic CD8 T cells that are crucial for an immune response against these viruses often become exhausted resulting in chronic infection. We elucidated the T cell response upon therapeutic vaccination in inducible transgenic mouse models in which variable percentages of antigen-expressing hepatocytes can be adjusted, providing mosaic antigen distribution and reflecting the varying viral antigen loads observed in patients. Vaccination-induced endogenous CD8 T cells could eliminate low antigen loads in liver but were functionally impaired if confronted with elevated antigen loads. Strikingly, only by conditioning the liver environment with TLR9 ligand prior and early after peripheral vaccination, successful immunization against high intrahepatic antigen density with its elimination was achieved. Moreover, TLR9 immunomodulation was also indispensable for functional memory recall after high frequency antigen challenge. Together, the results indicate that TLR9-mediated conditioning of liver environment during therapeutic vaccination or antigen reoccurrence is crucial for an efficacious intrahepatic T cell response.
Asunto(s)
Linfocitos T CD8-positivos/metabolismo , Hígado/metabolismo , Receptor Toll-Like 9/metabolismo , Animales , Hepacivirus/patogenicidad , Hepatitis B/inmunología , Hepatitis B/metabolismo , Hepatitis B/terapia , Virus de la Hepatitis B/patogenicidad , Hepatitis C/inmunología , Hepatitis C/metabolismo , Hepatitis C/terapia , Hepatocitos/virología , Inmunoterapia , Hígado/virología , Activación de Linfocitos , Ratones , Receptor Toll-Like 9/genéticaRESUMEN
Adenovirus-based vectors are promising tools for genetic vaccination. However, several obstacles have to be overcome prior to a routine clinical application of adenovirus-based vectors as efficacious vectored vaccines. The linear trisaccharide epitope αGal (alpha-Gal) with the carbohydrate sequence galactose-α-1,3-galactosyl-ß-1,4-N-acetylglucosamine has been described as a potent adjuvant for recombinant or attenuated vaccines. Humans and α-1,3-galactosyltransferase knockout mice do not express this epitope. Upon exposure of α-1,3-galactosyltransferase-deficient organisms to αGal in the environment, large amounts of circulating anti-Gal antibodies are produced consistently. Immunocomplexes formed between recombinant αGal-decorated vaccines and anti-Gal antibodies exhibit superior immunogenicity. We studied the effects of the trisaccharide epitope on CD8 T cell responses that are directed specifically to vector-encoded transgenic antigens. For that, covalently αGal-decorated adenovirus vectors were delivered to anti-Gal α-1,3-galactosyltransferase knockout mice. We generated replication-defective, E1-deleted adenovirus type 5 vectors that were decorated with αGal at the hexon hypervariable regions 1 or 5, at fiber knob, or at penton base. Surprisingly, none of the adenovirus immunocomplexes being formed from αGal-decorated adenovirus vectors and anti-Gal immunoglobulins improved the frequencies of CD8 T cell responses against the transgenic antigen ovalbumin. Humoral immunity directed to the adenovirus vector was neither increased. However, our data indicated that decoration of Ad vectors with the αGal epitope is a powerful tool to analyze the fate of adenovirus immunocomplexes in vivo.
Asunto(s)
Adenoviridae/genética , Complejo Antígeno-Anticuerpo , Cápside , Carbohidratos/inmunología , Vectores Genéticos , Adenoviridae/inmunología , Animales , Línea Celular , Femenino , Masculino , Ratones , Ratones NoqueadosRESUMEN
Pancreatic gene transfer could be useful to treat several diseases, such as diabetes mellitus, cystic fibrosis, chronic pancreatitis, or pancreatic cancer. Helper-dependent adenoviral vectors (HDAds) are promising tools for gene therapy because of their large cloning capacity, high levels of transgene expression, and long-term persistence in immunocompetent animals. Nevertheless, the ability of HDAds to transduce the pancreas in vivo has not been investigated yet. Here, we have generated HDAds carrying pancreas-specific expression cassettes, that is, driven either by the elastase or insulin promoter, using a novel and convenient plasmid family and homologous recombination in bacteria. These HDAds were delivered to the pancreas of immunocompetent mice via intrapancreatic duct injection. HDAds, encoding a CMV-GFP reporter cassette, were able to transduce acinar and islet cells, but transgene expression was lost 15 days postinjection in correlation with severe lymphocytic infiltration. When HDAds encoding GFP under the control of the specific elastase promoter were used, expression was detected in acinar cells, but similarly, the expression almost disappeared 30 days postinjection and lymphocytic infiltration was also observed. In contrast, long-term transgene expression (>8 months) was achieved with HDAds carrying the insulin promoter and the secretable alkaline phosphatase as the reporter gene. Notably, transduction of the liver, the preferred target for adenovirus, was minimal by this route of delivery. These data indicate that HDAds could be used for pancreatic gene therapy but that selection of the expression cassette is of critical importance to achieve long-term expression of the transgene in this tissue.
Asunto(s)
Terapia Genética/métodos , Vectores Genéticos/genética , Páncreas/metabolismo , Transducción Genética/métodos , Adenoviridae/genética , Fosfatasa Alcalina/sangre , Animales , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Inmunohistoquímica , Insulina/genética , Ratones , Ratones Endogámicos C57BL , Elastasa Pancreática/genética , Regiones Promotoras Genéticas/genéticaRESUMEN
UNLABELLED: Telomere shortening impairs liver regeneration in mice and is associated with cirrhosis formation in humans with chronic liver disease. In humans, telomerase mutations have been associated with familial diseases leading to bone marrow failure or lung fibrosis. It is currently unknown whether telomerase mutations associate with cirrhosis induced by chronic liver disease. The telomerase RNA component (TERC) and the telomerase reverse transcriptase (TERT) were sequenced in 1,121 individuals (521 patients with cirrhosis induced by chronic liver disease and 600 noncirrhosis controls). Telomere length was analyzed in patients carrying telomerase gene mutations. Functional defects of telomerase gene mutations were investigated in primary human fibroblasts and patient-derived lymphocytes. An increased incidence of telomerase mutations was detected in cirrhosis patients (allele frequency 0.017) compared to noncirrhosis controls (0.003, P value 0.0007; relative risk [RR] 1.859; 95% confidence interval [CI] 1.552-2.227). Cirrhosis patients with TERT mutations showed shortened telomeres in white blood cells compared to control patients. Cirrhosis-associated telomerase mutations led to reduced telomerase activity and defects in maintaining telomere length and the replicative potential of primary cells in culture. CONCLUSION: This study provides the first experimental evidence that telomerase gene mutations are present in patients developing cirrhosis as a consequence of chronic liver disease. These data support the concept that telomere shortening can represent a causal factor impairing liver regeneration and accelerating cirrhosis formation in response to chronic liver disease.