2016-2020: Ewald Lab, University of Virginia
Damaged or infected cells often release a protein called IL-1 that acts as a molecular alarm signal, calling in help from other cells. In the Ewald Lab, I tackled a new project studying the role of IL-1R—the protein that senses IL-1—during infection with the protozoan parasite Toxoplasma gondii.
We discovered that early in infection, IL-1 signaling prevents disease severity in some tissues like skeletal muscle and fat. However, long-term IL-1 signaling causes to cachexia (a form of chronic muscle wasting) and scarring in the liver and skeletal muscle.
Publications:
Belanger, M., Ball, A., Catteron, M., Kinman, A., Anbaei, P., Groff, B., Melchor, S., Lukens, J., & R. Pompano. 2020. Acute lymph node slices are a functional model system to study immunity ex vivo. ACS Pharmacology & Translational Science (accepted).
Melchor, S.J., Saunders, C.M., Sanders, I, Hatter, J.A., Byrnes, K.A,, Coutermarsh-Ott, S., & S.E. Ewald. 2020. IL-1R regulates disease tolerance and cachexia in T. gondii infection. Journal of Immunology. Jun 15;204(12):3329-3338. https://doi.org/10.4049/jimmunol.2000159 .
Melchor, S.J. & S.E. Ewald. 2019. Disease Tolerance in Toxoplasma infection. Frontiers in Cellular and Infection Microbiology (9): 185. https://doi.org/10.3389/fcimb.2019.00185 .
Hatter J., Kouche M., Melchor S.J.*, Ng K., Bouley D., Boothroyd J., & S. E. Ewald. 2018. Toxoplasma gondii infection triggers chronic cachexia and sustained commensal dysbiosis in mice. PLoS ONE. 13(10):e0204895 (*authors contributed equally). https://doi.org/10.1371/journal.pone.0204895 O .
Melchor, S.J., Hatter, J.A., LaTorre Castillo, E.A., Saunders, C.M., Sanders, I., Abebayehu, D., Barker, T., & S.E. Ewald. T. gondii infection induces IL-1R dependent cachexia and associated perivascular fibrosis of the muscle and liver in mice. Scientific Reports 10, 15724 (2020). https://doi.org/10.1038/s41598-020-72767-0 .
2015-2016: Petri Lab, University of Virginia
In the Petri lab, I designed a project to test how a protein called Regenerating protein 1 (Reg1) in maintains the integrity of the intestinal barrier during a range of different insults, including environmental enteropathy and infection with C. difficile.
Publications:
Steele, S. P., Melchor, S. J., & W. A. Petri Jr. 2016. Tuft Cells: New Players in Colitis. Trends in Molecular Medicine. 22(11):921-924. https://doi.org/10.1016/j.molmed.2016.09.005 .
2011-2012 Bell Lab, Brigham Young University
In the Bell lab, I studied whether biochemical changes (called oxidation) to the phospholipids in cell membranes made the membrane more likely to be destroyed by an enzyme called secretory phospholipase A2 (sPLA2).
I also designed an independent project testing whether sPLA2 could sense changes in the cell membrane caused by viral infection.
Publications:
Vaughn, A. R., Bell, T. A, Bailey, E. G., Askew, C., Franchino H., Hirsche, K., Kemsley, L., Melchor, S., Moulton, E., Schwab, M., Nelson, J., & J. D. Bell. 2014. Relationships between membrane water molecules and Patman equilibration kinetics at temperatures far above the phosphatidylcholine melting point. Biochimica et Biophysica Acta – Biomembranes. 1848(4):942-50. https://doi.org/10.1016/j.bbamem.2014.12.021 .
Gibbons E., Nelson J., Anderson L., Brewer K., Melchor S., Judd A. M., & J. D. Bell. 2013. Role of membrane oxidation in controlling the activity of human group IIa secretory phospholipase A(2) toward apoptotic lymphoma cells. Biochimica et Biophysica Acta.1828(2):670-6. https://doi.org/10.1016/j.bbamem.2012.09.013 .