Biology subjects

Munro, S. A.

Publications and source records attributed to Munro, S. A..

3 recordsLinked to original sources

bioRxiv2020

Identification of mutations that cooperate with defects in B cell transcription factors to initiate leukemia

The transcription factors EBF1 and PAX5 are frequently mutated in B cell acute lymphoblastic leukemia (B-ALL). We demonstrate that Pax5+/- x Ebf1+/- compound heterozygous mice develop highly penetrant leukemia. Similar results were seen in Pax5+/- x Ikzf1+/- and Ebf1+/- x Ikzf1+/- mice for B-ALL, or in Tcf7+/- x Ikzf1+/- mice for T cell leukemia. To identify genetic defects that cooperate with Pax5 and Ebf1 compound heterozygosity to initiate leukemia, we performed a Sleeping Beauty (SB) transposon screen that identified cooperating partners including gain-of-function mutations in Stat5 ([~]65%) and Jak1([~]68%), or loss-of-function mutations in Cblb (61%) and Myb (32%). These findings underscore the role of JAK/STAT5 signaling in B cell transformation and demonstrate unexpected roles for loss-of-function mutations in Cblb and Myb in leukemic transformation. RNA-Seq studies demonstrated upregulation of a PDK1>SGK3>MYC pathway; treatment of Pax5+/- x Ebf1+/- leukemia cells with PDK1 inhibitors blocked proliferation in vitro. Finally, we identified conserved transcriptional variation in a subset of genes between human leukemias and our mouse B-ALL models. Thus, compound haploinsufficiency for B cell transcription factors likely plays a critical role in transformation of human B cells and suggest that PDK1 inhibitors may be effective for treating patients with such defects.

cancer biology↗

bioRxiv2020

Single-cell analysis of developing B cells reveals dynamic gene expression networks that govern B cell development and transformation

SummaryIntegration of external signals and B-lymphoid transcription factor activities orchestrate B cell lineage commitment through alternating cycles of proliferation and differentiation, producing a diverse repertoire of mature B cells. We used single-cell transcriptomics and proteomics to characterize B cell development. Our analysis revealed unique transcriptional signatures that refine the pre-B cell expansion stages into novel pre-BCR-dependent and pre-BCR-independent proliferative phases. These changes correlate with unexpected dynamic and reciprocal changes in expression of the transcription factor EBF1 and the RNA binding protein YBX3, that are defining features of the pre-BCR-dependent stage. Using pseudotime analysis, we further characterize the expression kinetics of different biological modalities across B cell development, including transcription factors, cytokines, chemokines, and their associated receptors. Our findings reveal the underlying heterogeneity of developing B cells and point to key developmental nodes linked to B cell transformation.Competing Interest StatementThe authors have declared no competing interest.View Full Text

immunology↗

bioRxiv2018

Reproducing bench-scale cell growth and productivity

Reproducing, exchanging, comparing, and building on each others work is foundational to technology advances.1 Advancing biotechnology calls for reliable reuse of engineered strains.2 Reliable reuse of engineered strains requires reproducible growth and productivity. To demonstrate reproducibility for biotechnology, we identified the experimental factors that have the greatest effect on the growth and productivity of our engineered strains.3-6 We present a draft of a Minimum Information Standard for Engineered Organism Experiments (MIEO) based on this method. We evaluated the effect of 22 factors on Escherichia coli (E. coli) engineered to produce the small molecule lycopene, and 18 factors on E. coli engineered to produce red fluorescent protein (RFP). Container geometry and shaking had the greatest effect on product titer and yield. We reproduced our results under two different conditions of reproducibility:7 conditions of use (different fractional factorial experiments), and time (48 biological replicates performed on 12 different days over four months).

synthetic biology↗