Biology subjects

Swain, K.

Publications and source records attributed to Swain, K..

3 recordsLinked to original sources

bioRxiv2023

A Drug-Free Pathogen Capture and Neutralizing Nasal Spray to Prevent Emerging Respiratory Infections

Respiratory infections pose a global health crisis. Vaccines are pathogen specific, and new vaccines are needed for mutants and emerging pathogens. Here, we report a "drug free" prophylactic platform - a "Pathogen Capture and Neutralizing Spray" (PCANS) that acts via a multi-pronged approach to prevent a broad spectrum of respiratory infections. PCANS forms a protective coating in the nasal cavity that enhances the capture of large respiratory droplets. The coating acts as a physical barrier against a broad spectrum of viruses and bacteria, and rapidly neutralizes them, reducing the pathogen load by >99.99%. In mice, PCANS showed nasal retention for at least 8 h and was safe for daily administration. A single prophylactic dose of PCANS protected mice against supra-lethal dosages of a mouse-adapted H1N1 Influenza virus (PR8), reduced lung viral titer by >99.99%, improved survival, and suppressed pathological manifestations. Together, our data suggest PCANS as a promising daily-use prophylactic approach against current and emerging respiratory infections.

bioengineering↗

bioRxiv2023

Heterologous production of cyanophycin with Tatumella morbirosei cyanophycin synthetase

Microbial production of biopolymers represents a promising, sustainable alternative to current approaches for plastic production. Cyanophycin synthetase 1 (CphA1) produces cyanophycin - an attractive biopolymer consisting of a poly-L-aspartic acid backbone decorated with L-arginine side groups. In this work, a series of CphA1 enzymes from different bacteria were screened for heterologous cyanophycin production in engineered Escherichia coli, from which it was found that CphA1 from Tatumella morbirosei (TmCphA1) was especially productive. TmCphA1 was capable of supporting up to ~2-fold greater yields of insoluble cyanophycin than any other tested CphA1 enzymes, including 10.8-times more than CphA1 from Synechocystis sp. PCC6308. Finally, using a bench-scale bioreactor, cyanophycin production by TmCphA1-expressing E. coli reached up to 1.9 g per liter of culture by 48 h.

molecular biology↗

bioRxiv2020

A genome-scale CRISPR interference guide library enables comprehensive phenotypic profiling in yeast

CRISPR/Cas9-mediated transcriptional interference (CRISPRi) enables programmable gene knock-down, yielding interpretable loss-of-function phenotypes for nearly any gene. Effective, inducible CRISPRi has been demonstrated in budding yeast, but no genome-scale guide libraries have been reported. We present a comprehensive yeast CRISPRi library, based on empirical design rules, containing 10 distinct guides for most genes. Competitive growth after pooled transformation revealed strong fitness defects for most essential genes, verifying that the library provides comprehensive genome coverage. We used the relative growth defects caused by different guides targeting essential genes to further refine yeast CRISPRi design rules. In order to obtain more accurate and robust guide abundance measurements in pooled screens, we link guides with random nucleotide barcodes and carry out linear amplification by in vitro transcription. Taken together, we demonstrate a broadly useful platform for comprehensive, high-precision CRISPRi screening in yeast.

genomics↗