Donley, D. W. | Search bioRxiv

bioRxiv2024

Enhancing reproducibility and decentralization in single cell research with biocytometry

Biomedicine today is experiencing a shift towards decentralized data collection, which promises enhanced reproducibility and collaboration across diverse laboratory environments. This inter-laboratory study evaluates the performance of biocytometry, a method utilizing engineered bioparticles for enumerating cells based on their surface antigen patterns. In a decentralized framework, spanning 78 assays conducted by 30 users across 12 distinct laboratories, biocytometry consistently demonstrated significant statistical power in discriminating numbers of target cells at varying concentrations as low as 1 cell per 100,000 background cells. User skill levels varied from expert to beginner capturing a range of proficiencies. Measurement was performed in a decentralized environment without any instrument cross-calibration or advanced user training outside of a basic instruction manual. The results affirm biocytometry to be a viable solution for immunophenotyping applications demanding sensitivity as well as scalability and reproducibility and paves the way for decentralized analysis of rare cells in heterogeneous samples.

cell biology↗

bioRxiv2019

Latent Toxoplasma gondii infection increases soluble mutant huntingtin and promotes neurodegeneration in the YAC128 mouse model of Huntington's disease

Toxoplasma gondii causes a prevalent neuroinvasive protozoal pathogen that in immune competent individuals results in latent infection characterized by intra-cellular parasite cysts in brain. Despite life-long infection, the role of latent toxoplasmosis on chronic neurodegenerative processes is poorly understood. Huntingtons disease (HD) is a progressive neurodegenerative disorder caused by a dominant CAG repeat expansion in the huntingtin gene (HTT) that results in the expression and accumulation of mutant huntingtin protein (mHTT). The mutant HD gene is fully penetrant. However, there is significant variability in disease progression that is in part explained by as yet unidentified environmental factors. The kynurenine pathway of tryptophan metabolism (KP) is an inflammatory pathway and its activation is implicated in HD pathogenesis. KP upregulation also occurs in response to infection with Toxoplasma gondii suggesting that the latent infection may promote HD. We discovered that mice on the FVB/NJ background develop latent toxoplasmosis following infection with the ME49 strain of T. gondii. This finding enabled us to address the hypothesis that latent toxoplasmosis potentiates disease in the YAC128 mouse model of HD, as these mice are maintained on the FVB/NJ background. Wild-type and HD mice were infected at 2-months of age. During the 10-month follow-up, infection had adverse effects on mice of both genotypes. However, YAC128 HD mice demonstrated specific vulnerability to latent toxoplasmosis, as demonstrated by the presence of increased striatal degeneration, high levels of the blood neurodegeneration marker neurofilament light protein, and elevated brain soluble mHTT. Our studies have uncovered a novel HD-infection interaction in mice that provides insights into the large variability of the human HD phenotype.

neuroscience↗