Engineering Selectivity for Reduced Toxicity of Bacterial Kinase Inhibitors Using Structure-Guided Medicinal Chemistry.

Tuberculosis is a major global public health concern, and new drugs are needed to combat both the typical form and the increasingly common drug-resistant form of this disease. The essential tuberculosis kinase PknB is an attractive drug development target because of its central importance in several critical signaling cascades. A major hurdle in kinase inhibitor development is the reduction of toxicity due to nonspecific kinase activity in host cells. Here a novel class of PknB inhibitors was developed from hit aminopyrimidine 1 (GW779439X), which was originally designed for human CDK4 but failed to progress clinically because of high toxicity and low specificity. Replacing the pyrazolopyridazine headgroup of the original hit with substituted pyridine or phenyl headgroups resulted in a reduction of Cdk activity and a 3-fold improvement in specificity over the human kinome while maintaining PknB activity. This also resulted in improved microbiological activity and reduced toxicity in THP-1 cells and zebrafish.

CD4/CD8 Ratio as a Novel Marker for Increased Risk of High-Grade Anal Dysplasia and Anal Cancer in HIV+ Patients: A Retrospective Cohort Study.

BACKGROUND: People living with HIV are at risk for anal dysplasia/cancer. Screening/surveillance is costly and burdensome, and the frequency is not evidence based. Objective markers of increased risk of anal carcinogenesis are needed to tailor screening/surveillance. Low CD4/CD8 ratio is associated with increased overall cancer risk in people living with HIV but has yet to be examined for quantifying anal cancer risk. OBJECTIVE: We hypothesized that low CD4/CD8 ratios correlate with increased risk for high-grade anal dysplasia and cancer. DESIGN: This is a single-institution, retrospective review of people living with HIV from 2002 to 2018. SETTING: This study was conducted at the University of Wisconsin School of Medicine and Public Health. PATIENTS: Patients with advanced disease (high-grade anal dysplasia and/or anal cancer) were compared with patients with negative anal cytology. MAIN OUTCOME MEASURES: The independent variables were lowest (nadir) CD4/CD8 and CD4/CD8 nearest to screening/diagnosis. Logistic regression modeling was used to estimate the adjusted odds of advanced disease. RESULTS: A total of 377 people living with HIV were examined: 266 with negative cytology and 111 with advanced disease (16 cancer, 95 high-grade anal dysplasia). Mean nadir ratio and mean nearest ratio were lower in patients with advanced disease than in those with negative screening (0.26 vs 0.47 (p < 0.001) and 0.61 vs 0.87 (p < 0.001)). In adjusted analyses, increase in nadir ratio or nearest ratio of 1 unit conferred decreased risk of advanced disease (OR, 0.10; 95% CI, 0.02-0.45; p = 0.002) and (OR, 0.31; 95% CI, 0.12-0.83; p = 0.02). The optimal threshold for using CD4/CD8 ratio as a risk factor for advanced disease was 0.47 for nadir ratio (sensitivity 0.59 and specificity 0.91) and 0.95 for nearest ratio (sensitivity 0.56 and specificity 0.92). LIMITATIONS: This is a retrospective, single-institution study. CONCLUSIONS: Low CD4/CD8 ratio confers additional risk of high-grade anal dysplasia and anal cancer beyond the diagnosis of HIV, even when adjusting for known risks factors of anal cancer. Our data suggest that the CD4/CD8 ratio may be able to help identify people living with HIV who are at higher risk of anal cancer development. See Video Abstract at http://links.lww.com/DCR/B336. LA RELACIÓN CD4 / CD8 COMO UN MARCADOR NOVEDOSO PARA EL AUMENTO DEL RIESGO DE DISPLASIA ANAL DE ALTO GRADO Y CÁNCER ANAL EN PACIENTES VIH+: UN ESTUDIO DE COHORTE RETROSPECTIVO: Las personas que viven con el virus de la inmunodeficiencia humana están en riesgo de displasia / cáncer anal. La detección / vigilancia es costosa, laboriosa y la frecuencia no se basa en evidencias. Se necesitan marcadores objetivos de mayor riesgo de carcinogénesis anal para adaptar la detección / vigilancia. La relación baja de CD4 / CD8 se asocia con un mayor riesgo general de cáncer en personas que viven con el virus de inmunodeficiencia humana, pero aún no se ha examinado para cuantificar el riesgo de cáncer anal.Hicimos la hipotesis de que la relación baja de CD4 / CD8 se correlacionan con un mayor riesgo de displasia anal de alto grado y cáncer.Revisión retrospectiva de una sola institución de personas que viven con el virus de la inmunodeficiencia humana desde 2002 hasta 2018.Facultad de Medicina y Salud Pública de la Universidad de Wisconsin.Los pacientes con enfermedad avanzada (displasia anal de alto grado y / o cáncer anal) se compararon con pacientes con citología anal negativa.Las variables independientes más bajas fueron (nadir) CD4 / CD8 y la relación CD4 / CD8 más cercanas a la detección / diagnóstico. Se utilizó el modelo de regresión logística para estimar las probabilidades ajustadas de enfermedad avanzada.Se examinaron un total de 377 personas que viven con el virus de inmunodeficiencia humana, 266 con citología negativa y 111 con enfermedad avanzada (16 cáncer, 95 displasia anal de alto grado). La tasa nadir y la tasa media más cercana fueron más bajas en pacientes con enfermedad avanzada vs. aquellos con cribado negativo (0.26 v. 0.47 (p <0.001) y 0.61 v. 0.87 (p <0.001), respectivamente. En los análisis ajustados, el aumento en la tasa nadir o la tasa más cercana a una unidad confirió una disminución del riesgo de enfermedad avanzada (OR de 0,10 (IC del 95%: 0,02, 0,45, p = 0,002)) y (OR 0,31 (IC del 95%: 0,12, 0,83, p = 0.02)), respectivamente. El umbral óptimo para usar la relacion CD4 / CD8 como factor de riesgo de enfermedad avanzada fue 0,47 para la tasa nadir (sensibilidad 0,59 y especificidad 0,91) y 0,95 para la tasa más cercana (sensibilidad 0,56 y especificidad 0,92).Este es un estudio retrospectivo de una sola institución.La baja relación CD4 / CD8 confiere un riesgo adicional de displasia anal de alto grado y cáncer anal más allá del diagnóstico del virus de inmunodeficiencia humana, incluso cuando se ajustan los factores de riesgo conocidos de cáncer anal. Nuestros datos sugieren que la relación CD4/CD8 puede ayudar a identificar a las personas que viven con el virus de inmunodeficiencia humana que tienen un mayor riesgo de desarrollar cáncer anal. Consulte Video Resumen en http://links.lww.com/DCR/B336.

In Silico Screen and Structural Analysis Identifies Bacterial Kinase Inhibitors which Act with ß-Lactams To Inhibit Mycobacterial Growth.

New tools and concepts are needed to combat antimicrobial resistance. Actinomycetes and firmicutes share several eukaryotic-like Ser/Thr kinases (eSTK) that offer antibiotic development opportunities, including PknB, an essential mycobacterial eSTK. Despite successful development of potent biochemical PknB inhibitors by many groups, clinically useful microbiologic activity has been elusive. Additionally, PknB kinetics are not fully described, nor are structures with specific inhibitors available to inform inhibitor design. We used computational modeling with available structural information to identify human kinase inhibitors predicted to bind PknB, and we selected hits based on drug-like characteristics intended to increase the likelihood of cell entry. The computational model suggested a family of inhibitors, the imidazopyridine aminofurazans (IPAs), bind PknB with high affinity. We performed an in-depth characterization of PknB and found that these inhibitors biochemically inhibit PknB, with potency roughly following the predicted models. A novel X-ray structure confirmed that the inhibitors bound as predicted and made favorable protein contacts with the target. These inhibitors also have antimicrobial activity toward mycobacteria and nocardia. We demonstrated that the inhibitors are uniquely potentiated by ß-lactams but not antibiotics traditionally used to treat mycobacteria, consistent with PknB's role in sensing cell wall stress. This is the first demonstration in the phylum actinobacteria that some ß-lactam antibiotics could be more effective if paired with a PknB inhibitor. Collectively, our data show that in silico modeling can be used as a tool to discover promising drug leads, and the inhibitors we discovered can act with clinically relevant antibiotics to restore their efficacy against bacteria with limited treatment options.