Biology subjects

Ordonez, A. A.

Publications and source records attributed to Ordonez, A. A..

5 recordsLinked to original sources

bioRxiv2022

Adjunctive inhibition of the integrated stress response pathway accelerates bacterial clearance in a mouse model of tuberculosis

Tuberculosis (TB) is a devastating infectious disease that continues to cause millions of human deaths every year. Even though most cases of TB can be cured with a 6-month antibiotic combination therapy, these long treatment durations have led to the emergence of multi-drug resistance and pose a major hurdle to global TB control. Despite numerous advances in TB drug development, a substantially shortened treatment time has yet to be achieved. Given the rise in antibiotic resistance, an alternative strategy to the direct targeting of M. tuberculosis (M.tb) is the development of host-directed therapies (HDTs) that promote bacterial clearance and/or lung health when given adjunctive to standard TB antibiotics. We recently discovered that a small molecule inhibitor of the Integrated Stress Response (ISR), which is abnormally activated in TB and associated with the formation of necrotic granulomas, reduced M.tb numbers and lung inflammation in mice. Here, we evaluated the therapeutic potential of adjunctive ISR inhibition in the context of standard TB therapy. Throughout the course of treatment, ISR inhibition robustly lowered bacterial burdens compared to standard TB therapy alone and accelerated the time-to-sterility in mice, as demonstrated by significantly reduced relapse rates after 4 months of treatment. In addition, mice receiving adjunctive ISR inhibition tended to have reduced lung necrosis and inflammation. Together, our findings identify the ISR pathway as a promising therapeutic target with the potential of shortening TB treatment durations and improving lung health.

microbiology↗

bioRxiv2021

Non-invasive Imaging of Sense of Smell by Tracking the Voltage-Gated Sodium Channel NaV1.7

The sense of smell (olfaction) is one of the most important senses for animals including humans. Despite significant advances in the understanding mechanism of olfaction, currently, there are no objective non-invasive methods that can identify loss of smell. Covid-19-related loss of smell has highlighted the need to develop methods that can identify loss of olfaction. Voltage-gated sodium channel 1.7 (NaV1.7) plays a critical role in olfaction by aiding the signal propagation to the olfactory bulb. We have identified several conditions such as chronic inflammation and viral infections such as Covid-19 that lead to loss of smell correlate with downregulation of NaV1.7 expression at transcript and protein levels in the olfactory epithelium. Leveraging this knowledge, we have developed a novel fluorescent probe Tsp1a-IR800 that targets NaV1.7. Using fluorescence imaging we can objectively measure the loss of sense of smell in live animals non-invasively. We also demonstrate that our non-invasive method is semiquantitative because the loss of fluorescence intensity correlates with the level of smell loss. Our results indicate, that our probe Tsp1a-IR800, can objectively diagnose anosmia in animal and human subjects using infrared fluorescence. We believe this method to non-invasively diagnose loss of smell objectively is a significant advancement in relation to current methods that rely on highly subjective behavioral studies and can aid in studying olfaction loss and the development of therapeutic interventions.

neuroscience↗

bioRxiv2021

Host regulator PARP1 contributes to sex differences and immune responses in a mouse model of tuberculosis

Tuberculosis (TB) is a devastating infectious disease responsible for nearly 2 million deaths annually that has a poorly understood male bias. Elucidating the basis of this male bias may enable precision medicine interventions for TB treatment and prevention. Here, we identify the master regulator Poly(ADP-ribose) Polymerase 1 (PARP1) as a driver of TB sex differences. We found that infection with M. tuberculosis (M. tb) triggers robust PARP activation in mouse lungs, suggesting that PARP1 activation is a fundamental host response to TB. Remarkably, PARP1 deletion abolished known sex differences in TB cytokine responses and blunted the early induction of TNF, IL-1{beta}, IFN{gamma}, MCP-1, and IL-6, particularly in male mice. In contrast, PARP1 was required for IL-10 induction in male or female mice. PARP1 deletion was protective against TB in female mice, resulting in significantly prolonged survival and reduced bacterial burden, but impaired TB containment in male mice. Our findings indicate that PARP1 contributes to TB sex differences via sexually divergent immune regulation and uniquely enhances early proinflammatory responses in males that prove beneficial for TB containment.

immunology↗

bioRxiv2021

Sulforaphane exhibits in vitro and in vivo antiviral activity against pandemic SARS-CoV-2 and seasonal HCoV-OC43 coronaviruses

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), has incited a global health crisis. Currently, there are no orally available medications for prophylaxis for those exposed to SARS-CoV-2 and limited therapeutic options for those who develop COVID-19. We evaluated the antiviral activity of sulforaphane (SFN), a naturally occurring, orally available, well-tolerated, nutritional supplement present in high concentrations in cruciferous vegetables with limited side effects. SFN inhibited in vitro replication of four strains of SARS-CoV-2 as well as that of the seasonal coronavirus HCoV-OC43. Further, SFN and remdesivir interacted synergistically to inhibit coronavirus infection in vitro. Prophylactic administration of SFN to K18-hACE2 mice prior to intranasal SARS-CoV-2 infection significantly decreased the viral load in the lungs and upper respiratory tract and reduced lung injury and pulmonary pathology compared to untreated infected mice. SFN treatment diminished immune cell activation in the lungs, including significantly lower recruitment of myeloid cells and a reduction in T cell activation and cytokine production. Our results suggest that SFN is a promising treatment for prevention of coronavirus infection or treatment of early disease.

microbiology↗

bioRxiv2020

A chemiluminescent protease probe for rapid, sensitive, and inexpensive detection of live Mycobacterium tuberculosis

Tuberculosis (TB) is a top-ten cause of death worldwide. Successful treatment is often limited by insufficient diagnostic capabilities, especially at the point of care in low-resource settings. The ideal diagnostic must be fast, cheap, and require minimal clinical resources while providing high sensitivity, selectivity, and the ability to differentiate live from dead bacteria. We describe here the development of a Fast, Luminescent, and Affordable Sensor of Hip1 (FLASH) for the diagnosis and monitoring of drug sensitivity of Mycobacterium tuberculosis (Mtb). FLASH is a selective chemiluminescent substrate for the Mtb protease Hip1 that when processed, produces visible light that can be measured with a high signal to noise ratio using inexpensive sensors. FLASH is sensitive to fmol of recombinant Hip1 enzyme in vitro and can detect as few as thousands of Mtb cells in culture or in human sputum samples within minutes. The probe is highly selective for Mtb compared to other non-tuberculous mycobacteria and can distinguish live from dead cells. Importantly, FLASH can be used to measure antibiotic killing of Mtb in culture with greatly accelerated timelines compared to traditional protocols. Overall, FLASH has the potential to enhance both TB diagnostics and drug resistance monitoring in resource-limited settings. One Sentence SummaryA luminescent probe enables sensitive detection of Mycobacterium tuberculosis for diagnostics, treatment monitoring, and drug susceptibility testing.

microbiology↗