RESUMO
Accurate pathogen detection and diagnosis is paramount in clinical success of treating patients. There are two general paradigms in pathogen detection: molecular and immuno-based, and phage-based detection is a third emerging paradigm due to its sensitivity and selectivity. Molecular detection methods look for genetic material specific for a given pathogen in a sample usually by polymerase chain reaction (PCR). Immuno-methods look at the pathogen components (antigens) by antibodies raised against that pathogen specific antigens. There are different variations and products based on these two paradigms with advantages and disadvantages. The third paradigm at least for bacterial pathogen detection entails bacteriophages specific for a given bacterium. Sensitivity and specificity are the two key parameters in any pathogen detection system. By their very nature, bacteriophages afford the best sensitivity for bacterial detection. Bacteria and bacteriophages form the predator-prey pair in the evolutionary arms race and has coevolved over time to acquire the exquisite specificity of the pair, in some instances at the strain level. This specificity has been exploited for diagnostic purposes of various pathogens of concern in clinical and other settings. Many recent reviews focus on phage-based detection and sensor technologies. In this review, we focus on a very special group of pathogens that are of concern in biodefense because of their potential misuse in bioterrorism and their extremely virulent nature and as such fall under the Centers for Disease and Prevention (CDC) Category A pathogen list. We describe the currently available phage methods that are based on the usual modalities of detection from culture, to molecular and immuno- and fluorescent methods. We further highlight the gaps and the needs for more modern technologies and sensors drawing from technologies existing for detection and surveillance of other pathogens of clinical relevance.
Assuntos
Bactérias/virologia , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Bacteriófagos , Armas Biológicas , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno , Humanos , Receptores Virais , Sensibilidade e EspecificidadeRESUMO
We have recently isolated novel IFN-inducible gene, Gene associated with Retinoid-Interferon-induced Mortality-1 (GRIM-1), using a genetic technique. Moderate ectopic expression of GRIM-1 caused growth inhibition and sensitized cells to retinoic acid (RA)/IFN-induced cell death while high expression caused apoptosis. GRIM-1 depletion, using RNAi, conferred a growth advantage. Three protein isoforms (1α, 1ß and 1γ) with identical C-termini are produced from GRIM-1 mRNA. We show that GRIM-1 isoforms interact with NAF1 and DKC1, two essential proteins required for box H/ACA sno/sca RNP biogenesis and suppresses box H/ACA RNA levels in mammalian cells by delocalizing NAF1. Suppression of these small RNAs manifests as inefficient rRNA maturation and growth suppression. Interestingly, yeast Shq1p also caused growth suppression in mammalian cells. Consistent with its growth-suppressive property, GRIM-1 expression is lost in a number of human primary prostate tumors. Our observations support a recent study that GRIM-1 might act as a co-tumor suppressor in the prostate.
Assuntos
Proteínas Reguladoras de Apoptose/genética , Regulação Neoplásica da Expressão Gênica , RNA Ribossômico/genética , RNA Nucleolar Pequeno/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Células HeLa , Humanos , Imuno-Histoquímica , Interferon beta/farmacologia , Masculino , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Ribossômico/metabolismo , RNA Nucleolar Pequeno/metabolismo , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Tretinoína/farmacologiaRESUMO
Using a genome-wide technical knockout, we isolated a newly identified set of GRIM (genes associated with retinoid-interferon-induced mortality) genes; GRIM genes mediate IFN- and retinoic-acid (RA)-induced cell death. Here, we describe the isolation and characterization of one such gene, GRIM-1. Three proteins, with identical C-termini, were produced from the GRIM-1 open reading frame when this gene was transcribed and translated in vitro. These protein isoforms, designated GRIM-1alpha, GRIM-1beta and GRIM-1gamma, differentially suppressed growth via apoptosis in various cell lines. We also show that a caspase-dependent mechanism generates the proapoptotic GRIM-1 isoforms. Lastly, GRIM-1 isoforms differentially blocked maturation of 18S ribosomal RNA, consistent with their respective growth-suppressive ability. Together, these studies identified a novel protein involved in growth suppression and cell death.
