Harvard Catalyst Profiles

Proinflammatory Th17 and Th1 cells are implicated in human autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA). Sex differences strongly impact the prevalence of autoimmunity. We reported that transcription factor Upstream Stimulatory Factor 2 (USF2) is induced during proinflammatory Th17 differentiation and promotes proinflammatory cytokine expression, and the mRNA level of USF2 is elevated in peripheral Th17-enriched cells isolated from female RA patients resistant to anti-TNF therapy compared to female patients who respond to the treatment (Hu, D., et al., PNAS, 2020). The goal of this project is to determine the impact of USF2 on human proinflammatory Th17 and Th1 development and function in the context of sexual dimorphism. We will analyze immune capacity-relevant protein synthesis and gene expression in in vitro differentiated human Th17 and Th1 cells regulated by USF2 in the context of sexual dimorphism. The student will work together with the Principal Investigator in the lab to conduct experiments and analyze and interpret the results. Students with prior experience with flow cytometry, cell culture, ELISA, RNA isolation, qPCR analysis are encouraged to apply.

One major immune cell type that has been implicated in the autoimmune attack in Multiple sclerosis (MS) is called a Th17 cells. There are different types of Th17 cells in terms of their ability to cause inflammation and disease. Some of them produce a potent chemical called interferon gamma and these cells are called Th1/17 cells. These cells are very inflammatory and thus have the potential to cause major damage to the brain in MS. However, the mechanism underlying the development of Th1/17 cells in MS is not well understood. We found that a protein called a “heat shock protein 70” or Hsp70 was greatly increased in Th1/17 cells isolated from MS patients, and level of the gene that makes Hsp70 returned to normal after patients received MS disease-modifying therapies. We found that the Hsp70 protein amplified the disease inducing properties of Th1/17 cells Interestingly, at the same time, the Hsp70 protein could dampen these disease inducing properties suggesting that the Hsp70 protein may be a negative regulator of Th1/17 development. We hypothesize that the balance between the pro and anti-inflammatory pathways regulated by the Hsp70 protein is critical for controlling the disease inducing properties of Th17 cells and maintaining the balance of the immune system which is disrupted in MS. Our goals are (1) to determine whether the effect of increased Hsp70 protein activity in Th1/17 cells is primarily to enhance the disease-inducing capacity of Th1/17 cells; (2) to determine the genes involved by which the Hsp70 protein regulates the disease-inducing capacity of Th1/Th17 cells and to determine whether these genes are dysregulated in MS, and (3) to determine whether the decreased Hsp70 protein activity after MS disease-modifying therapy makes these cells less inflammatory and whether this beneficial effect is not seen in patients who do not respond to the disease-modifying therapies, (4) to determine whether the increased inflammatory capacity of Th1/17 cells is associated with progression from relapsing to secondary progressive MS. We will (1) conduct sophisticated gene analysis on individual T cells isolated from MS patients and healthy controls to further define in which T cell subsets the Hsp70 protein is dysregulated in MS, (2) measure the chemical production by Hsp70 stimulated Th17 cells and how these chemicals affect other immune cells called macrophages, (3) manipulate the genes which our preliminary results suggest are involved in inducing the Hsp70 protein, determine how these genes work and determine whether these mechanisms do not function properly in MS, and (4) conduct gene analysis on individual of Th1/17 cells isolated from treated MS patients to assess their inflammatory capacity and determine if their inflammatory capacity correlates with treatment responses and disease progression.