By Debbie Bunch
Experimental Nasal Spray Blocks Nearly 100% of Respiratory Infections in Mice
Researchers from Brigham and Women’s Hospital have developed a drug-free nasal spray that may one day be able to fight off both viral and bacterial infections before they can take hold.
According to co-senior author Nitin Joshi, PhD, the spray was developed using ingredients from the FDA’s Inactive Ingredient Database that have been previously used in approved nasal sprays, or from the FDA’s Generally Recognized as Safe list of ingredients. Known as the Pathogen Capture and Neutralizing Spray (PCANS), the drug-free formulation blocks pathogens by forming a gel-like matrix that traps respiratory droplets, immobilizes the pathogens, and then neutralized them.
So far, the nasal spray has only been tested in mice, with results indicating that a single dose could effectively block infection from an influenza virus known as PR8 at 25 times the lethal dose. Virus levels in the lungs were reduced by more than 99.99% while the inflammatory cells and cytokines in the lungs remained normal.
The spray demonstrated nasal retention in mice for up to eight hours.
“In a rigorous mouse model study, prophylactic treatment with PCANS demonstrated exceptional efficacy, with treated mice exhibiting complete protection, while the untreated group showed no such benefit,” said co-senior author Yohannes Tesfaigzi, PhD.
The investigators believe these results provide a strong foundation for future research to explore the use of PCANS in a broader context and suggest they may even be able to block allergens and reduce allergy symptoms.
The paper was published by Advanced Materials.
Immune Cells in the Lungs Respond to a Sugar Rush
Sugar may play a bigger role in fighting infections in the lungs than previously thought, report Irish researchers publishing in the Proceedings of the National Academy of Sciences.
Their study zeroed in on tissue-resident natural killer (NK) cells in the lungs and how they respond to glucose. The authors note the behavior and metabolic function of these cells has not been well explored, and they wanted to find out more about how they figure into the immune system in the lungs.
Their work showed that these cells are —
- Metabolically distinct from their counterparts in the blood, showing a unique capacity to rapidly metabolize glucose in response to environmental changes, such as during infections.
- Exhibit a higher glycolytic capacity compared to non-tissue-resident NK cells that allows them to generate energy and necessary metabolites more efficiently, enabling a swift immune response.
- Primed to respond quickly to increased glucose availability during infections, enhancing their ability to mount an effective immune defense.
Given these results, the investigators noted that metabolism could be a target for immune-supportive therapies for patients with chronic infections or even cancer.
“These findings are exciting because they establish that the NK cells in the lung are metabolically different to the NK cells found in blood,” said lead study author Dr. Gráinne Jameson. “This is impactful because it will enable the investigation of dysfunctional NK cells in respiratory diseases and shows that the metabolism of lung resident NKs is a tractable target for inhalable therapies for many settings of lung disease including cancer and infection.”
Artificial Neural Network Diagnoses BPD in Preterm Infants
Artificial intelligence is changing many aspects of society and medicine is rapidly becoming one of them. In a new study presented at the European Respiratory Society meeting, researchers from Switzerland outlined their use of an artificial neural network (ANN) to detect bronchopulmonary dysplasia (BPD) in preterm infants using only their breath sounds.
The authors explain ANNs are mathematical models that are trained to predict and classify using huge amounts of data. Until now, using ANNs to predict respiratory disease in preterm infants has been a challenge because methods used to assess their lung function, such as the multiple-breath washout technique or capnography, are complicated and require special equipment.
These investigators decided to use a simple alternative — an air flow time series (TS) measured during the infant’s tidal breathing (Tb). The technique was tested in 139 term and 190 pre-term infants who had been assessed for BPD. A soft face mask and sensor were used to record their breathing for ten minutes while they slept.
Overall, 47 of the 190 preterm infants were diagnosed with mild BPD, 54 with moderate BPD, and 31 with severe BPD. The researchers then used 100 consecutive regular breaths from each infant to train, validate, and test a long short-term memory recurrent ANN. The breaths were carefully inspected to exclude sighs or other artifacts that could skew results.
Sixty percent of the data was used for training and 20% for validation. The remaining 20% went to the “model unseen” to see if it could identify infants with BPD.
The unseen test data model achieved 96% accuracy, 100% specificity, 96% sensitivity, and 98% precision for detecting BPD.
“Sufficiently long TS of inspiratory and expiratory flow measured in infants during Tb can be used to train an ANN capable of accurately detecting BPD,” concluded the authors.
