Epigenetic modulators of B cell fate identified through coupled phenotype-transcriptome analysis

Area of Science:

• Immunology
• Genomics
• Drug Discovery

Background:

• High-throughput screening is crucial for identifying compounds that modulate immune cell function.
• Integrating cellular phenotypes with molecular mechanisms is essential for developing targeted therapeutics for immune disorders and hematological malignancies.

Purpose of the Study:

• To develop and apply a novel integrated approach combining phenotypic and genomic analysis for drug screening.
• To identify compounds targeting the epigenetic machinery of B cells and their impact on humoral immunity.

Main Methods:

• Multiplexed Analysis of Cells sequencing (MAC-seq), a modified Digital RNA with perturbation of Genes (DRUGseq) method, was employed.
• MAC-seq was used to screen compounds targeting B cell epigenetic machinery, measuring proliferation, survival, differentiation, and transcription.
• Arrayed CRISPR screening was used to functionally dissect downstream effectors of polycomb repressive complex 2 (PRC2).

Main Results:

• MAC-seq revealed that PRC2 inhibitors enhance antibody secreting cell (ASC) differentiation in both murine and human B cells in vitro.
• In vivo validation using T cell-dependent immunization in mice confirmed the pro-differentiation effects of PRC2 inhibitors.
• CRISPR screening identified novel regulators of B cell differentiation, including Mybl1, Myof, Gas7, and Atoh8.

Conclusions:

• Integrated phenotype-transcriptome analysis combined with drug screening is effective for uncovering molecular circuitry in lymphocyte fate decisions.
• PRC2 inhibitors represent a potential therapeutic strategy for modulating humoral immunity.
• The study highlights novel regulators of B cell differentiation, offering new avenues for therapeutic development.