Office of Pharmaceutical Quality Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA.
Dr. Thacker studies how immune cells, specifically a type of white blood cell called T cells, interact with joint cells in conditions like rheumatoid arthritis. This is a condition where the immune system mistakenly attacks the joints, leading to pain and inflammation. His research particularly examines a protein called B7-H3 produced by joint cells, which can influence how T cells behave—changing their level of activity and the chemicals they produce. By exploring this relationship, Dr. Thacker aims to find new ways to treat rheumatoid arthritis and possibly other diseases that involve inflammation.
Key findings
In lab experiments, reducing levels of the protein B7-H3 caused resting T cells to produce more inflammatory chemicals.
Already-activated T cells showed reduced production of inflammatory chemicals when B7-H3 levels were lowered.
Identifying B7-H3 as a potential target may lead to new treatments for rheumatoid arthritis and similar inflammatory diseases.
Frequently asked questions
Does Dr. Thacker study rheumatoid arthritis?
Yes, Dr. Thacker's research focuses on rheumatoid arthritis and the interactions between immune cells and the cells in the joints.
What specific proteins does Dr. Thacker research?
Dr. Thacker studies the protein B7-H3, which plays a role in the activity of T cells in the context of inflammatory diseases.
How could Dr. Thacker's research help patients with inflammatory diseases?
His work could lead to the development of new treatments targeting the B7-H3 protein, offering better control over inflammation in diseases like rheumatoid arthritis.
Publications in plain English
Proceedings of the 2024 FDA-CRCG Workshop: Scientific and Regulatory Considerations for Assessment of Immunogenicity Risk for Generic Peptide and Oligonucleotide Drug Products.
2026
The AAPS journal
Lee JK, Lee HN, Agrawal S, Balsamo JA, Clerman A +40 more
Plain English Researchers gathered to discuss how to evaluate the risk of immune reactions to generic medications made from peptides and oligonucleotides. They focused on improving methods and regulations to ensure these drugs are safe and effective, which is essential since many complex generic products are on the market. The workshop provided new strategies that can help streamline the approval process for these medications, ultimately benefiting patient care.
Who this helps: This helps patients who rely on affordable and safe generic medications.
BSL2-compliant lethal mouse model of SARS-CoV-2 and variants of concern to evaluate therapeutics targeting the Spike protein.
2022
Frontiers in immunology
Manangeeswaran M, Ireland DDC, Thacker SG, Lee HN, Kelley-Baker L +8 more
Plain English This study looked at how different versions of the SARS-CoV-2 virus, especially its spike protein, affect the severity of infections in mouse models. Researchers found that young genetically modified mice were more likely to get sick from both the original virus and its variants, with increased dying rates observed when infected. They also discovered that treatment with specific antibodies against the spike protein could protect against these lethal infections, highlighting the spike protein's crucial role in the virus's ability to cause disease.
Who this helps: This research benefits doctors and scientists working on COVID-19 treatments and vaccines.
Detection of innate immune response modulating impurities (IIRMI) in therapeutic peptides and proteins: Impact of excipients.
2022
Frontiers in immunology
Thacker SG, Her C, Kelley-Baker L, Ireland DDC, Manangeeswaran M +2 more
Plain English This study looked at how impurities in therapeutic proteins and peptides can influence the immune system and potentially affect treatment safety and effectiveness. Researchers found that common ingredients added to these products, called excipients, can reduce the sensitivity of tests designed to detect harmful impurities, which could lead to overlooked risks. For example, when testing three different kinds of drug products, lower sensitivity was seen in detecting impurities that could trigger immune responses.
Who this helps: This benefits patients who rely on safe and effective biologic therapies.
Effect of Fatty Acid Composition in Polysorbate 80 on the Stability of Therapeutic Protein Formulations.
2021
Pharmaceutical research
Pegues MA, Szczepanek K, Sheikh F, Thacker SG, Aryal B +5 more
Plain English This study looked at how the types of fatty acids in Polysorbate 80 affect the stability of drug formulations containing therapeutic proteins, which are essential for treating various health conditions. Researchers found that while the composition of the fatty acids didn’t significantly change the proteins' overall stability or effectiveness, the version of Polysorbate 80 with more oleic acid led to more tiny particles forming under stressful conditions like high temperatures. This matters because these small particles can affect the safety and effectiveness of the drug.
Who this helps: Patients receiving therapeutic protein treatments.
CpG ODN D35 improves the response to abbreviated low-dose pentavalent antimonial treatment in non-human primate model of cutaneous leishmaniasis.
2020
PLoS neglected tropical diseases
Thacker SG, McWilliams IL, Bonnet B, Halie L, Beaucage S +8 more
Plain English This study looked at how a substance called D35 can enhance a shorter, lower dose treatment for cutaneous leishmaniasis, a disease that causes painful skin lesions affecting about 0.7-1 million people each year. Researchers found that monkeys treated with D35 alongside a low dose of standard medication had smaller lesions and healed more quickly compared to those who only received the medication. This matters because it could lead to safer and more effective treatments that are easier for patients to complete, reducing the chances of harmful side effects and resistance to the drug.
Who this helps: Patients suffering from cutaneous leishmaniasis.
Tofacitinib Ameliorates Murine Lupus and Its Associated Vascular Dysfunction.
2017
Arthritis & rheumatology (Hoboken, N.J.)
Furumoto Y, Smith CK, Blanco L, Zhao W, Brooks SR +12 more
Plain English This study looked at the effects of a drug called tofacitinib on mice with a condition similar to lupus, a serious autoimmune disease. Researchers found that tofacitinib significantly improved various symptoms of lupus, such as kidney problems and skin inflammation, and also helped improve blood vessel function within 6 to 8 weeks of treatment. The results are important because they indicate that tofacitinib could be a promising treatment for lupus and its related cardiovascular issues.
Who this helps: This helps patients with lupus and their doctors by providing a potential new treatment option.
Dietary α-cyclodextrin reduces atherosclerosis and modifies gut flora in apolipoprotein E-deficient mice.
2017
Molecular nutrition & food research
Sakurai T, Sakurai A, Chen Y, Vaisman BL, Amar MJ +9 more
Plain English This study looked at how adding a substance called α-cyclodextrin (α-CD) to the diets of mice with a genetic mutation that makes them prone to heart disease affected their heart health and gut bacteria. The researchers found that mice fed a high-fat diet with α-CD had 65% fewer fatty deposits in their arteries compared to those on a regular high-fat diet. These changes in artery health were linked to shifts in gut bacteria and lower cholesterol levels, indicating that α-CD may play a significant role in reducing heart disease risk.
Who this helps: This research benefits patients at risk for heart disease and healthcare providers seeking effective dietary interventions.
Lipoprotein X Causes Renal Disease in LCAT Deficiency.
2016
PloS one
Ossoli A, Neufeld EB, Thacker SG, Vaisman B, Pryor M +12 more
Plain English The research studied how a specific particle, lipoprotein-X (LpX), affects the kidneys in patients with a rare condition called LCAT deficiency. The researchers found that when LpX was introduced to mice lacking the LCAT enzyme, it caused kidney damage and proteinuria, which is a sign of renal disease. This is important because it shows that LpX is harmful to the kidneys and could be used as an indicator to track the effectiveness of treatments aimed at replacing LCAT.
Who this helps: This helps patients with LCAT deficiency and their doctors in understanding and managing kidney-related complications.
High-density lipoprotein reduces inflammation from cholesterol crystals by inhibiting inflammasome activation.
2016
Immunology
Thacker SG, Zarzour A, Chen Y, Alcicek MS, Freeman LA +3 more
Plain English This study explored how high-density lipoprotein (HDL), often considered "good" cholesterol, can reduce inflammation caused by cholesterol crystals, which are linked to heart disease. The researchers found that HDL significantly decreases the release of a harmful protein called IL-1β, which drives inflammation, and it also reduces the recruitment of inflammatory cells in mice after they were given cholesterol crystals. These results are important because they highlight a new way HDL can help protect against diseases like atherosclerosis by moderating inflammation.
Who this helps: Patients at risk for heart disease and doctors managing their care.
Elevated interleukin-10: a new cause of dyslipidemia leading to severe HDL deficiency.
2015
Journal of clinical lipidology
Moraitis AG, Freeman LA, Shamburek RD, Wesley R, Wilson W +15 more
Plain English This research studied the role of a substance called interleukin-10 (IL-10) in causing low levels of good cholesterol (HDL-C) in certain patients with blood cancers and autoimmune conditions. The study found that all four patients with severely low HDL-C had high levels of IL-10, which returned to normal after they received treatment. Additionally, in a larger group of patients with an autoimmune condition, higher IL-10 levels were linked to lower HDL-C levels, and an experiment showed that giving IL-10 injections caused a significant drop in HDL-C and LDL-C levels within a week.
Who this helps: This research helps patients with blood cancers and autoimmune diseases by identifying a potential cause of their cholesterol issues.
Increased plasma cholesterol esterification by LCAT reduces diet-induced atherosclerosis in SR-BI knockout mice.
2015
Journal of lipid research
Thacker SG, Rousset X, Esmail S, Zarzour A, Jin X +10 more
Plain English This study looked at how a protein called LCAT affects cholesterol levels and heart disease in mice that are missing a specific cholesterol receptor. The researchers found that mice with increased levels of LCAT had healthier cholesterol profiles, including 51% less buildup of plaque in their arteries compared to mice without LCAT. This is important because it suggests that boosting LCAT could help reduce the development of heart disease caused by high-fat diets.
Who this helps: Patients at risk for heart disease.
Synthesis of cholesterol analogues bearing BODIPY fluorophores by Suzuki or Liebeskind-Srogl cross-coupling and evaluation of their potential for visualization of cholesterol pools.
2014
Chembiochem : a European journal of chemical biology
Liu Z, Thacker SG, Fernandez-Castillejo S, Neufeld EB, Remaley AT +1 more
Plain English This study created specialized compounds that can help scientists visualize cholesterol in cells. Researchers made modified cholesterol molecules linked to fluorescent markers and found that these new compounds behaved similarly to regular cholesterol in cell tests. This is important because it allows for better tracking and understanding of cholesterol levels in cells, which is crucial for health monitoring.
Who this helps: This benefits researchers studying cholesterol-related diseases and treatments.
Type I interferons modulate vascular function, repair, thrombosis, and plaque progression in murine models of lupus and atherosclerosis.
2012
Arthritis and rheumatism
Thacker SG, Zhao W, Smith CK, Luo W, Wang H +7 more
Plain English This study looked at how a type of immune protein, called type I interferons (IFNs), affects blood vessel health in mice with lupus and atherosclerosis. The researchers found that when the signaling of these proteins was blocked, the mice showed better blood flow and less severe artery disease, while exposure to IFNs led to worse circulation and increased blood clotting. This is important because it suggests that type I IFNs might worsen heart disease in lupus patients, highlighting a potential target for improving their cardiovascular health.
Who this helps: This research benefits patients with lupus and doctors treating them.
Inflammasome activation of IL-18 results in endothelial progenitor cell dysfunction in systemic lupus erythematosus.
2011
Journal of immunology (Baltimore, Md. : 1950)
Kahlenberg JM, Thacker SG, Berthier CC, Cohen CD, Kretzler M +1 more
Plain English This research studied how a specific part of the immune system, called the inflammasome, affects blood vessel repair in patients with systemic lupus erythematosus (SLE), an autoimmune disease. The researchers found that high levels of a molecule called IL-18 in SLE patients are linked to poor functioning of cells that help repair blood vessels, with increased IL-18 levels correlating with dysfunction (though specific numbers were not provided). This matters because it reveals how inflammation contributes to heart problems in SLE, highlighting a potential target for new treatments to improve vascular health in these patients.
Who this helps: Patients with systemic lupus erythematosus and related cardiovascular issues.
Lupus-prone New Zealand Black/New Zealand White F1 mice display endothelial dysfunction and abnormal phenotype and function of endothelial progenitor cells.
2010
Lupus
Thacker SG, Duquaine D, Park J, Kaplan MJ
Plain English This study examined how certain mice, which are used to model lupus—a severe autoimmune disease—show issues with specific blood cell types that help blood vessels function. The researchers found that lupus-prone mice had fewer of these helper cells, more of them were dying off, and their ability to support blood vessel health was impaired. This was linked to problems in their blood vessels that could lead to further complications, including heart disease.
Who this helps: This research is valuable for doctors treating patients with lupus, as it highlights potential areas for intervention to prevent heart-related issues.
A distinct subset of proinflammatory neutrophils isolated from patients with systemic lupus erythematosus induces vascular damage and synthesizes type I IFNs.
2010
Journal of immunology (Baltimore, Md. : 1950)
Denny MF, Yalavarthi S, Zhao W, Thacker SG, Anderson M +3 more
Plain English This study focused on a specific type of immune cell called low-density granulocytes (LDGs) from patients with systemic lupus erythematosus (SLE) to understand their role in the disease. The researchers found that LDGs are highly activated and produce substances that can damage blood vessels, contributing to heart problems in SLE patients. Specifically, these cells can kill endothelial cells and hinder the repair of blood vessels, which is crucial because they prevent the formation of healthy blood vessel cells.
Who this helps: This research helps patients with lupus, especially those at risk for heart disease.
The detrimental effects of IFN-α on vasculogenesis in lupus are mediated by repression of IL-1 pathways: potential role in atherogenesis and renal vascular rarefaction.
2010
Journal of immunology (Baltimore, Md. : 1950)
Thacker SG, Berthier CC, Mattinzoli D, Rastaldi MP, Kretzler M +1 more
Plain English This study looked at how a specific protein, IFN-α, negatively affects blood vessel formation in people with lupus, a disease that increases heart disease risk. The researchers found that IFN-α disrupts the normal healing processes of blood vessels, leading to fewer healthy cells and increased damage. This is important because it highlights a new way lupus can contribute to heart problems and kidney injury.
Who this helps: This helps patients with lupus by identifying potential new treatment targets for reducing their risk of heart disease and kidney issues.
The peroxisome proliferator-activated receptor gamma agonist pioglitazone improves cardiometabolic risk and renal inflammation in murine lupus.
2009
Journal of immunology (Baltimore, Md. : 1950)
Zhao W, Thacker SG, Hodgin JB, Zhang H, Wang JH +7 more
Plain English This study focused on how a drug called pioglitazone affects heart and kidney health in mice with lupus, a disease that increases the risk of heart problems. The researchers found that mice treated with pioglitazone showed better blood vessel function, reduced inflammation in the kidneys, and improved insulin sensitivity. Specifically, those treated with the drug had fewer immune complexes and less immune cell infiltration in their kidneys, indicating less damage and inflammation.
Who this helps: This benefits patients with lupus by potentially reducing their risk of heart disease and kidney damage.
Interactions of T cells with fibroblast-like synoviocytes: role of the B7 family costimulatory ligand B7-H3.
2008
Journal of immunology (Baltimore, Md. : 1950)
Tran CN, Thacker SG, Louie DM, Oliver J, White PT +4 more
Plain English Researchers found that cells in the joints of people with rheumatoid arthritis (a disease where the immune system attacks joints) produce a protein called B7-H3 that helps activate immune cells called T cells. When they reduced B7-H3 levels in lab experiments, T cells behaved differently depending on whether they were already activated or not—resting T cells made more inflammatory chemicals, while already-activated T cells made fewer. This discovery matters because B7-H3 could be a new target for treating rheumatoid arthritis and possibly other inflammatory diseases.