Biology subjects

Farmer, R.

Publications and source records attributed to Farmer, R..

3 recordsLinked to original sources

bioRxiv2023

Re-education of myeloid immune cells to reduce regulatory T cell expansion and impede breast cancer progression

Immune checkpoint blockade (ICB) has revolutionized cancer therapy but has had limited utility in several solid tumors such as breast cancer, a major cause of cancer-related mortality in women. Therefore, there is considerable interest in alternate strategies to promote an anti-cancer immune response. We demonstrate that NR0B2, a protein involved in cholesterol homeostasis, functions within myeloid immune cells to modulate the NLRP3 inflammasome and reduce the expansion of immune-suppressive regulatory T cells (Treg). Loss of NR0B2 increased mammary tumor growth and metastasis. Small molecule agonists, including one developed here, reduced Treg expansion, reduced metastatic growth and improved the efficacy of ICB. This work identifies NR0B2 as a target to re-educate myeloid immune cells providing proof-of-principle that this cholesterol-homeostasis axis may have utility in enhancing ICB. Brief SummaryImmune therapy has been disappointing for breast cancer. NR0B2 within myeloid immune cells reduces the expansion of Tregs, a highly immune suppressive subtype historically challenging to target. NR0B2 within myeloid immune cells represses the inflammasome, leading to reduced Treg expansion and subsequent tumor growth/metastasis. Activation of NR0B2 with small molecule agonists, including one developed herein, attenuates tumor growth and metastasis in murine models of mammary cancer.

cancer biology↗

bioRxiv2022

Multiparameter stimulation mapping of signaling states in single pediatric immune cells reveals heightened tonic activation during puberty

Cellular stimulation via factors such as cytokines followed by multiparameter single-cell measurements is a powerful approach to interrogate cellular functions. However, transforming such high-dimensional data into biological insights presents unique challenges, particularly given the extensive response heterogeneity among single cells, such as the presence of bimodal responding versus non-responding subpopulations upon stimulation. Here we present an unsupervised high-dimensional approach for analyzing stimulation responses at the single cell level (HDStIM) and apply it to evaluate how pediatric development may shape peripheral immune cell signaling states and responsiveness to stimulations in 42 subjects (age: 2 - 16). We show that in comparison to the conventional approach of assessing one marker at a time by averaging across single cells, HDStIM can effectively learn, in an unsupervised fashion, the multi-parameter signature of responding versus non-responding cells to accurately quantify responses within cell populations. HDStIM reveals that the extent of pre-stimulation/baseline activation of interferon-related and TCR signaling molecules in myeloid and T cells, respectively, increases during puberty. This suggests that puberty is marked by a heightened "tonic" activation state in these cells, perhaps to strengthen defense against pathogens during this period of human development.

immunology↗

bioRxiv2022

Behavioral and imaging analysis of Foxg1 heterozygous mice

FOXG1 Syndrome (FS) is a devastating neurodevelopmental disorder that is caused by a heterozygous loss-of-function (LOF) mutation of the FOXG1 gene, which encodes a transcriptional regulator important for telencephalic brain development. People with FS have marked developmental delays, impaired ambulation, movement disorders, seizures, and behavior abnormalities including autistic features. Current therapeutic approaches are entirely symptomatic, however the ability to rescue phenotypes in mouse models of other genetic neurodevelopmental disorders such as Rett syndrome, Angelman syndrome, and Phelan-McDermid syndrome by postnatal expression of gene products has led to hope that similar approaches could help modify the disease course in other neurodevelopmental disorders such as FS. While FoxG1 protein function plays a critical role in embryonic brain development, the ongoing adult expression of FoxG1 and behavioral phenotypes that present when FoxG1 function is removed postnatally provides support for opportunity for improvement with postnatal treatment. Here we generated a new mouse allele of Foxg1 that disrupts protein expression and characterized the behavioral and structural brain phenotypes in heterozygous mutant animals. These mutant animals display changes in locomotor behavior, gait, anxiety, social interaction, aggression, and learning and memory compared to littermate controls. Additionally, they have structural brain abnormalities reminiscent of people with FS. This information provides the framework for future studies to evaluate the potential for post-natal expression of FoxG1 to modify the disease course in this severe neurodevelopmental disorder.

neuroscience↗