RESUMEN
By bearing a papain-like core structure and a cysteine-based catalytic triad, deamidase can convert glutamine to glutamic acid or asparagine to aspartic acid to modify the functions of host target proteins resulting in the blocking of eukaryotic host cell function. Legionella pneumophila effector Lpg2148 (MvcA) is a deamidase, a structural homolog of cycle inhibiting factor (Cif) effectors. Lpg2148 and Cif effectors are functionally diverse, with Lpg2148 only catalyzing ubiquitin but not NEDD8. However, a detailed understanding of substrate specificity is still missing. Here, we resolved the crystal structure of Lpg2148â¯at 2.5â¯Å resolution and obtained rigid-body modeling of Lpg2148 with C-terminus deleted ubiquitin (1-68) (ubΔc) complex using HADDOCK, which shows that the C-terminus of ubiquitin is flexible in recognition. We also conducted the truncated analysis to demonstrate that Leu71 of ubiquitin is necessary for its interaction with Lpg2148. Moreover, Val33 of Lpg2148â¯at the edge of a channel plays a vital role in the interaction and is limited by the length of the C-terminus of ubiquitin, which may help to explain the selectivity of ubiquitin over NEDD8. In summary, these results enrich our knowledge of substrate recognition of deamidase.
Asunto(s)
Amidohidrolasas/metabolismo , Ubiquitina/metabolismo , Células HeLa , Humanos , Legionella pneumophila , Proteína NEDD8/metabolismo , Especificidad por SustratoRESUMEN
Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by dopaminergic neuron death in the substantia nigra, leading to motor dysfunction. Autophagy dysregulation has been implicated in PD pathogenesis. This study explores the role of miR-214-3p in PD, focusing on its impact on autophagy and dopaminergic neuron viability. Using in vitro and in vivo models, we demonstrate that miR-214-3p inhibits autophagy and promotes dopaminergic neuron apoptosis. Behavioral assessments and molecular analyses reveal exacerbation of PD symptoms upon miR-214-3p overexpression. Furthermore, mechanistic investigations identify ATG3 as a target, shedding light on miR-214-3p's regulatory role in autophagy. These findings enhance our understanding of PD pathogenesis and propose miR-214-3p as a potential biomarker and therapeutic target for modulating autophagy and neuronal survival in PD.
Asunto(s)
MicroARNs , Enfermedad de Parkinson , Humanos , Animales , Ratones , Enfermedad de Parkinson/patología , Sustancia Negra/patología , Apoptosis , Autofagia , Neuronas Dopaminérgicas/patología , Ratones Endogámicos C57BLRESUMEN
Persistent inflammation and extensive immune activation have been associated with HIV-1/SIV pathogenesis. Previously, we reported that cholesterol-25-hydroxylase (CH25H) and its metabolite 25-hydroxycholesterol (25-HC) had a broad antiviral activity in inhibiting Zika, Ebola, and HIV-1 infection. However, the underlying immunological mechanism of CH25H and 25-HC in inhibiting viral infection remains poorly understood. We report here that 25-HC effectively regulates immune responses for controlling viral infection. CH25H expression was interferon-dependent and induced by SIV infection in monkey-derived macrophages and PBMC cells, and 25-HC inhibited SIV infection both in permissive cell lines and primary monkey lymphocytes. 25-HC also strongly inhibited bacterial lipopolysaccharide (LPS)-stimulated inflammation and restricted mitogen-stimulated proliferation in primary monkey lymphocytes. Strikingly, 25-HC promoted SIV-specific IFN-γ-producing cellular responses, but selectively suppressed proinflammatory CD4+ T lymphocytes secreting IL-2 and TNF-α cytokines in vaccinated mice. In addition, 25-HC had no significant immunosuppressive effects on cytotoxic CD8+ T lymphocytes or antibody-producing B lymphocytes. Collectively, 25-HC modulated both innate and adaptive immune responses toward inhibiting HIV/SIV infection. This study provides insights into improving vaccination and immunotherapy regimes against HIV-1 infection.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Hidroxicolesteroles/inmunología , Inmunidad Celular , Inmunidad Innata , Macrófagos/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Animales , Linfocitos T CD4-Positivos/patología , Linfocitos T CD4-Positivos/virología , Línea Celular , Femenino , Macaca , Macrófagos/patología , Macrófagos/virología , Ratones , Ratones Noqueados , Síndrome de Inmunodeficiencia Adquirida del Simio/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/patología , Esteroide Hidroxilasas/genética , Esteroide Hidroxilasas/inmunologíaRESUMEN
Though immune correlates for protection are still under investigation, potent cytotoxic T lymphocyte responses are desirable for an ideal HIV-1 vaccine. PD-1 blockade enhances SIV-specific CD8+ T cells. However, little information has been reported about how it affects the immunogenicity and protection of prophylactic SIV vaccines in nonhuman primates. Here, we show that PD-1 blockade during vaccination substantially improved protective efficacy in SIV challenged macaques. The PD-1 pathway was blocked using a monoclonal antibody specific to human PD-1. Administration of this antibody effectively augmented and sustained vaccine-induced SIV-specific T cell responses for more than 42 weeks after first immunization in rhesus monkeys, as compared with SIV vaccination only. Importantly, after intrarectally repeated low-dosage challenge with highly pathogenic SIVmac239, monkeys with PD-1 blockade during vaccination achieved full protection against incremental viral doses of up to 50,000 TICD50. These findings highlight the importance of PD-1 blockade during vaccination for the development of HIV vaccines.
Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/inmunología , VIH-1/fisiología , Receptor de Muerte Celular Programada 1/inmunología , Vacunas contra el SIDAS/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Anticuerpos Bloqueadores/administración & dosificación , Anticuerpos Monoclonales/administración & dosificación , Modelos Animales de Enfermedad , Resistencia a la Enfermedad , Humanos , Macaca , Transducción de SeñalRESUMEN
Based on structure modification and a high-throughput Jurkat-Lat cell screening model, we found that GIBH-LRA002, ethyl-2-amino-3-cyano-9-methyl-4-(trifluoromethyl)-4,9-dihydropyrano[2,3-b]indole-4-carboxylate, effectively reactivated the latent proviruses in a Jurkat-Lat cell line and primary CD4+ T cells from both chronic SIV-infected rhesus macaques and HIV-1 patients but without inducing systemic activation, making this compound attractive for potentially treating HIV-1 infection.
RESUMEN
Dual-functional biomineral-vaccine core-shell nanohybrids are obtained using recombinant adenovirus serotype 5 (rAd5) as templates, which efficiently masks the neutralizing epitope of vaccines and preserve their original immunogenicity. The versatile vaccine hybrid can evade the preexisting anti-Ad5 immunity, leading to boosted multifunctional antigen-specific cytokine-secreting T cell responses and presenting promising applications of vaccine-material hybrid for the rational design of vaccines.