Probes for INS

BACKGROUND: Melioidosis is endemic in Southeast Asia and Northern Australia and is caused by the Gram-negative, facultative intracellular pathogen Burkholderia pseudomallei. Diagnosis of melioidosis is often difficult because of the protean clinical presentation of the disease, and it may mimic other diseases, such as tuberculosis. There are many different strains of B. pseudomallei that have been isolated from patients with melioidosis, but it was not clear if they could cause a similar disease in a chronic BALB/c murine model of melioidosis. Hence, we wanted to examine chronically infected mice exposed to different strains of B. pseudomallei to determine if there were differences in the host immune response to the pathogen. RESULTS: We identified common host immune responses exhibited in chronically infected BALB/c mice, although there was some heterogeneity in the host response in chronically infected mice after exposure to different strains of B. pseudomallei. They all displayed pyogranulomatous lesions in their spleens with a large influx of monocytes/macrophages, NK cells, and neutrophils identified by flow cytometry. Sera from chronically infected mice by ELISA exhibited elevated IgG titers to the pathogen, and we detected by Luminex micro-bead array technology a significant increase in the expression of inflammatory cytokines/chemokines, such as IFN-?, IL-1?, IL-1?, KC, and MIG. By immunohistochemical and in situ RNA hybridization analysis we found that the increased expression of proinflammatory cytokines (IL-1?, IL-1?, TNF-?, IFN-?) was confined primarily to the area with the pathogen within pyogranulomatous lesions. We also found that cultured splenocytes from chronically infected mice could express IFN-?, TNF-?, and MIP-1? ex vivo without the need for additional exogenous stimulation. In addition by flow cytometry, we detected significant amounts of intracellular expression of TNF-? and IFN-? without a protein transport blocker in monocytes/macrophages, NK cells, and neutrophils but not in CD4+ or CD8+ T cells in splenocytes from chronically infected mice. CONCLUSION: Taken together the common features we have identified in chronically infected mice when 10 different human clinical strains of B. pseudomallei were examined could serve as biomarkers when evaluating potential therapeutic agents in mice for the treatment of chronic melioidosis in humans

The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has created a global health emergency. While most human disease is mild to moderate, some infections lead to a severe disease characterized by acute respiratory distress, hypoxia, anosmia, ageusia, and, in some instances, neurological involvement. Small-animal models reproducing severe disease, including neurological sequela, are needed to characterize the pathophysiological mechanism(s) of disease and to identify medical countermeasures. Transgenic mice expressing the human angiotensin-converting enzyme 2 (hACE2) viral receptor under the control of the K18 promoter develop severe and lethal respiratory disease subsequent to SARS-CoV-2 intranasal challenge when high viral doses are used. Here, we report on SARS-CoV-2 infection of hamsters engineered to express the hACE2 receptor under the control of the K18 promoter. K18-hACE2 hamsters infected with a relatively low dose of 100 or 1,000 PFU of SARS-CoV-2 developed a severe and lethal disease, with most animals succumbing by day 5 postinfection. Hamsters developed severe lesions and inflammation within the upper and lower respiratory system, including infection of the nasal cavities causing marked destruction of the olfactory epithelium as well as severe bronchopneumonia that extended deep into the alveoli. Additionally, SARS-CoV-2 infection spread to the central nervous system (CNS), including the brain stem and spinal cord. Wild-type (WT) hamsters naturally support SARS-CoV-2 infection, with the primary lesions present in the respiratory tract and nasal cavity. Overall, infection in the K18-hACE2 hamsters is more extensive than that in WT hamsters, with more CNS involvement and a lethal outcome. These findings demonstrate the K18-hACE2 hamster model will be valuable for studying SARS-CoV-2. IMPORTANCE The rapid emergence of SARS-CoV-2 has created a global health emergency. While most human SARS-CoV-2 disease is mild, some people develop severe, life-threatening disease. Small-animal models mimicking the severe aspects of human disease are needed to more clearly understand the pathophysiological processes driving this progression. Here, we studied SARS-CoV-2 infection in hamsters engineered to express the human angiotensin-converting enzyme 2 viral receptor under the control of the K18 promoter. SARS-CoV-2 produces a severe and lethal infection in transgenic hamsters that mirrors the most severe aspects of COVID-19 in humans, including respiratory and neurological injury. In contrast to other animal systems, hamsters manifest disease with levels of input virus more consistent with natural human infection. This system will be useful for the study of SARS-CoV-2 disease and the development of drugs targeting this virus.

Loss of kidney function is a common feature of COVID-19 infection, but serum creatinine (SCr) is not a sensitive or specific marker of kidney injury. We tested whether molecular biomarkers of tubular injury measured at hospital admission were associated with AKI in those with COVID-19 infection.This is a prospective cohort observational study consisting of 444 consecutive SARS-CoV-2 patients enrolled in the Columbia University Emergency Department at the peak of New York's pandemic (March-April 2020). Urine and blood were collected simultaneously at hospital admission (median time: day 0, IQR 0-2 days) and urine biomarkers analyzed by ELISA and by a novel dipstick. Kidney biopsies were probed for biomarker RNA and for histopathologic acute tubular injury (ATI) scores.Admission uNGAL was associated with AKI diagnosis (267±301 vs. 96±139 ng/mL, P < 0.0001) and staging; uNGAL levels >150ng/mL demonstrated 80% specificity and 75% sensitivity to diagnose AKI-stage 2-3. Admission uNGAL quantitatively associated with prolonged AKI, dialysis, shock, prolonged hospitalization, and in-hospital death, even when admission SCr was not elevated. The risk of dialysis increased almost 4-fold per standard deviation of uNGAL independently of baseline SCr, co-morbidities, and proteinuria [OR(95%CI): 3.59 (1.83-7.45), P < 0.001]. In COVID-19 kidneys, NGAL mRNA expression broadened in parallel with severe histopathological injury (ATI). Conversely, low uNGAL levels at admission ruled out stage 2-3 AKI (NPV 0.95, 95%CI: 0.92-0.97) and the need for dialysis (NPV: 0.98, 95%CI: 0.96-0.99)). While proteinuria and uKIM-1 implicated tubular injury, neither were diagnostic of AKI stages.In COVID-19 patients, uNGAL quantitatively associated with histopathological injury (ATI), the loss of kidney function (AKI), and the severity of patient outcomes.