Biology subjects

Campbell, P. L.

Publications and source records attributed to Campbell, P. L..

3 recordsLinked to original sources

bioRxiv2026

Ocrelizumab Modulates Both B and T Cell Immune Capacities in Multiple Sclerosis

To understand the molecular and cellular mechanisms beyond B-cell depletion with the anti-CD20 monoclonal antibody ocrelizumab, we used comprehensive muti-modal flow cytometry and functional assays in a prospective longitudinal multiple sclerosis (MS) cohort. Ocrelizumab depleted the vast majority of B cells and showed selective effects on different B cells subsets. Analysis of residual/replenished B cells revealed relative enrichment of regulatory B cells like CD27+CD43+ B1 and CD24hiCD38hi transitional B cells, and reduction of CD27+ memory B cell subsets and CD19+IgD+CD27-naive B cells at early time points (1-3 month) and before subsequent infusions at 4-7 months, 11-14 months, and >18 months. CD20+ T cells and peripheral helper T-cells (Tph) were also reduced. RNA sequencing analysis showed B1 cells have significantly higher expression of LGALS1, KCNN4, ITGB1, and IL2RB. Compared to transitional B cells, B1 cells also displayed significantly higher expression of tissue homing molecules ITGAX (CD11c), S100A4, ITGB1, and CXCR3. IL10 signaling pathway is increased in these B cells. Ex vivo B cell functional assays indicated the residual/replenishing B cells were anergic following ocrelizumab, with increased IL10/TNF and IL10/IL6 ratios under BCR stimulation. Ocrelizumab treatment may create a self-reinforcing regulatory circuit: the reduction of Tph cells could alleviate suppression of regulatory B cells, which subsequently expand and further promote regulatory T cell networks via IL2RB, LGALS1, and an increased IL-10 signaling pathway.

immunology↗

bioRxiv2020

Inhibition of histone readers bromodomain extra-terminal proteins alleviates scleroderma fibrosis

Binding of the bromodomain and extra-terminal domain proteins (BETs) to acetylated histone residues is critical for gene transcription. This study sought to determine the anti-fibrotic efficacy and potential mechanisms of BET inhibition in systemic sclerosis (SSc). Blockade of BETs was done using a pan BET inhibitor JQ1, BRD2 inhibitor BIC1, or BRD4 inhibitors AZD5153 or ARV825. BET inhibition, specifically BRD4 blockade, showed anti-fibrotic effects in an animal model of scleroderma and in patient-derived diffuse cutaneous (dc)SSc fibroblasts. Transcriptome analysis of JQ1-treated dcSSc fibroblasts revealed differentially expressed genes related to extracellular matrix, cell cycle, and calcium signaling. The anti-fibrotic effect of BRD4 inhibition was at least in part mediated by downregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII-) and reduction of intracellular calcium concentrations. These results suggest that targeting calcium pathways or BRD4 might be novel therapeutic approaches for progressive tissue fibrosis.

pharmacology and toxicology↗

bioRxiv2018

Identification of Pirin as a Molecular Target of the CCG-1423/CCG-203971 Series of Anti-Fibrotic and Anti-Metastatic Compounds

A series of compounds (including CCG-1423 and CCG-203971) discovered through an MRTF/SRF dependent luciferase screen has shown remarkable efficacy in a variety of in vitro and in vivo models, including melanoma metastasis and bleomycin-induced fibrosis. Although these compounds are efficacious, the molecular target is unknown. Here, we describe affinity isolation-based target identification efforts which yielded pirin, an iron-dependent co-transcription factor, as a target of this series of compounds. Using biophysical techniques including isothermal titration calorimetry and X-ray crystallography, we verify that pirin binds these compounds in vitro. We also show with genetic approaches that pirin modulates MRTF-dependent SRE.L Luciferase activation. Finally, using both siRNA and a previously validated pirin inhibitor, we show a role for pirin in TGF-p induced gene expression in primary dermal fibroblasts. A recently developed analog, CCG-257081, which co-crystallizes with pirin, is also effective in the prevention of bleomycin-induced dermal fibrosis.

pharmacology and toxicology↗