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Marguerite Buzza, PhD

Academic Title:

Research Associate

Primary Appointment:



BioPark1, 800 West Baltimore St, 235

Phone (Primary):

(410) 706-8223



Education and Training

I was awarded my PhD in Medicine (Biochemistry and Molecular Biology) at Monash University, Victoria, Australia in 2004, where I continued my thesis research as a post-doctoral fellow in the laboratory of Prof. Phillip Bird until 2006. I was then awarded a competitive CJ Martin Overseas Training Fellowship, from the National Health & Medical Research Council (Australia), to continue my post-doctoral training in the laboratory of Prof. Toni Antalis here at the University of Maryland. I became a faculty member of the Department of Physiology in 2012. My research career has focused on understanding the physiological functions of a specialised group of enzymes known as proteases, that mediate the specific cleavage or degradation of other proteins, resulting in a variety of fundamental biological responses.

My thesis studies focused on the biology of the serine protease Granzyme B, a cytotoxic protease used by cells of the immune system to kill virally infected or malignant cells, and also the role of a specific Granzyme B inhibitor (PI-9) in the protection of normal cells during local immune responses, and in the prevention of Granzyme B-mediated auto-immune pathologies in the placenta and testis. Since joining the University of Maryland, the major focus of my research has been to elucidate the role of another serine protease (Matriptase), a multi-domain more complex protease which is found anchored to the cell surface of epithelial tissues such as the skin and intestinal epithelium. After our initial discovery that Matriptase plays a critical role in maintaining the integrity of intestinal epithelium, my research is currently focused on understanding the contribution of Matriptase-mediated barrier formation in the protection from the development of Inflammatory Bowel Diseases such as Crohn's Disease and Ulcerative Colitis, and the mechanisms by which Matriptase expression and activity is regulated.

Highlighted Publications

Buzza, M.S., Johnson, T.A., Conway, G.D., Martin, E.W., Mukhopadhyay, S., Shea-Donohue, T., Antalis, T.M. (2017). Inflammatory cytokines down-regulate the barrier-protective prostasin-matriptase proteolytic cascade early in experimental colitis. J Biol Chem. Jun 30;292(26):10801-10812.  PMCID: PMC5491767.

Antalis, T.M., Conway, G.D., Peroutka, R.J., Buzza, M.S. (2016). Membrane-anchored proteases in endothelial cell biology. Curr Opin Hematol. 23(3):243-52.  PMCID: PMC4882107.

Driesbaugh, K.H., Buzza, M.S., Martin, E.W., Conway, G.D., Kao, J.P., Antalis, T.M. (2015). Proteolytic activation of the protease-activated receptor (PAR)-2 by the glycosylphosphatidylinositol-anchored serine protease testisin. J Biol Chem. 2015 Feb 6;290(6):3529-41.  PMCID: PMC4319020

Alaish, S.M., Timmons, J., Smith, A., Buzza, M.S., Murphy, E., Zhao, A., Sun, Y., Turner, D.J., Shea-Donohue, T., Antalis, T.M., Cross, A., Dorsey, S.G. (2013). Candidate genes for limiting cholestatic intestinal injury identified by gene expression profilingPhysiol Rep. Sep;1(4). doi: 10.1002/phy2.73.  PMCID: PMC3808870

Buzza, M.S., Martin E.W., Driesbaugh K.H., Desilets A., Leduc R., and Antalis T.M. (2013) Prostasin is required for matriptase activation in intestinal epithelial cells to regulate closure of the paracellular pathway. J Biol Chem. Feb 26. [Epub ahead of print].  PMCID: PMC3624416

Netzel-Arnett S, Buzza M. S., Shea-Donohue T, Desilets A,  Leduc R, Fasano A, Bugge H, Antalis, TM. (2012) Matriptase protects against experimental colitis and promotes intestinal barrier recovery.  Inflammatory Bowel Diseases. 18(7):1303-14.  PMCID: PMC3288858

Antalis, TA., Buzza M. S., Hodge, KM, Hooper, JD. and Netzel-Arnett, S. (2010). The Cutting Edge: Membrane Anchored Serine Protease Activities in the Pericellular Microenvironment. Invited Review. Biochem J. Jun 15;428(3):325-46.  PMCID: PMC3680374

Additional Publication Citations

Buzza, M.S., Netzel-Arnett, S., Shea-Donohue, T., Zhao, A., Lin, C-Y., List, K., Szabo, R., Fasano, A., Bugge, T.H. and Antalis, T.A. (2010).  The membrane-anchored serine protease matriptase regulates epithelial barrier formation and permeability in the intestineProc Natl Acad Sci U S A. Mar 2;107(9):4200-5 *a commentary on this manuscript was published in the "Highlights from the Literature" section of the journal Physiology, 25:128-131, 2010.  PMCID: PMC2840089

Tripathi, A., Lammers, K. M., Goldbulm, S., Shea-Donohue, T., Netzel-Arnett, S., Buzza,   M.S., Antalis, T.M., Vogel, S.N, Zhao, A., Yang, S., Arrietta, M.C., Meddings, J.B. and Fasano, A. (2009). Identification of human Zonulin, a physiological modulator of tight junctions, as Pre-haptoglobin-2Proc Natl Acad Sci U S A. 106(39):16799-804.  PMCID: PMC2744629

Tonnetti, L., Netzel-Arnett, S., Darnell, G.A., Hayes, T., Buzza, M.S., Anglin, I.E., Suhrbier, A. and Antalis, T.M. (2008). SerpinB2 protection of retinoblastoma protein from calpain enhances tumor cell survivalCancer Res. 68(14):5648-57.  PMCID: PMC2561898

Buzza, M.S., Dyson, J.M., Choi, H., Gardiner E.E., Andrews, R.K., Kaiserman, D., Mitchell, C.A., Berndt, M.C., Dong, J.F. and Bird, P.I. (2008). Antihemostatic activityof human granzyme B mediated by cleavage of von Willebrand factorJ Biol Chem. 283(33):22498-504.

Buzza, M.S. and Bird P.I. (2006). Extracellular granzymes: current perspectivesBiol. Chem. 387(7):827-37.

Buzza, M.S., Hosking P. and Bird, P.I. (2006). The granzyme B inhibitor, PI-9, is differentially expressed during placental development and up-regulated in hydatidiform molesPlacenta. 27(1):62-9.

Buzza, M.S., Zamurs, L., Sun, J., Bird, C.H., Smith, A I., Trapani, J.A., Froelich, C.J., Nice, E.C. and Bird P.I. (2005). Extracellular matrix remodeling by human granzyme B via cleavage of vitronectin, fibronectin and laminin. J Biol Chem. 280(25):23549-58.

Law R. H., Irving, J.A., Buckle, A.M., Ruzyla K., Buzza, M., Bushtannyk-Puhalovich T.A., Beddoe, T. C., Nguyen K., Worrall, D.M., Bottomley, S.P, Bird, P.I., Rossjohn J., Whisstock, J.C. (2005). The high resolution crystal structure of the human tumor suppressor maspin reveals a novel conformational switch in the G-helixJ Biol Chem. 280(23): 22356-64.

Hirst C.E., Buzza, M.S., Bird, C.H., Warren, H.S., Cameron, P.U., Zhang, M., Ashton-Rickardt, P.G. and Bird, P.I. (2003). The intracellular granzyme B inhibitor PI-9, is up-regulated during accessory cell maturation and effector cell degranulation, and its overexpression enhances CTL potencyJ Immunol. 170(2): 805-15

*Buzza, M.S., *Hirst, C.E., Sutton, V.R., Trapani, J.A., Loveland, K.L. and Bird, P.I. (2001). Perforin-independent expression of granzyme B and proteinase inhibitor 9 in human testis and placenta suggests a role for granzyme B-mediated proteolysis in reproduction.  Mol Hum Reprod. 7(12): 1133-42. *Equal first author with Hirst, as noted on title page.

Bird, C.H., Blink, E.J., Hirst, C.E., Buzza, M.S., Steele, P.M., Sun, J., Jans, D.A. and Bird P.I. (2001). Nucleocytoplasmic distribution of the ovalbumin serpin PI-9 requires a non-conventional nuclear import pathway and the export factor Crm1Mol Cell Biol. 21(16): 5396-407. PMCID: PMC87262

Buzza, M.S., Hirst, C.E., Bird, C.H., Hosking, P., McKendrick, J. and Bird P.I. (2001). The granzyme B inhibitor, PI-9, is present in endothelial cells and mesothelial cells, suggesting it protects bystander cells during immune responsesCell Immunol. 210(1): 21-9.

Sun, J., Bird, C.H., Buzza, M.S., McKee, K.E., Whisstock, J.C. and Bird, P.I. (1999). Expression and purification of recombinant human granzyme B from Pichia pastorisBiochem Biophys Res Commun. 216(2):251-5.

Martin, E.W., Buzza, M.S., Driesbaugh, K.H., Liu, S., Fortenberry, Y.M., Leppla, S.H., Antalis, T.M. (2015) Targeting the membrane-anchored serine protease testisin with a novel engineered anthrax toxin prodrug to kill tumor cells and reduce tumor burden. Oncotarget. 2015 Sep 15. PMID: 26392335

Publications - Book chapters
Antalis T.M., and Buzza M.S. Extracellular: Plasma Membrane Proteases – Serine Proteases. R.A. Bradshaw and P.D. Stahl (Editors-in-Chief), In: Encyclopedia of Cell Biology, Vol 1, Waltham, MA: Academic Press, 2016, pp.650-660.

Research Interests

Matriptase is one of a unique group of serine proteases that is directly tethered to the surface of epithelial cells that line the intestinal tract. We have determined that Matriptase, which is localized to adherens junctions in polarized intestinal epithelial cells, is required for closure of the paracellular pathway through an atypical PKC-mediated signaling pathway that regulates tight junction formation. Recently my research has involved understanding the contribution of Matriptase-mediated barrier formation in Inflammatory Bowel Diseases (IBD). We found that Matriptase expression is markedly down-regulated in human IBD, where increased intestinal permeability is thought to be causally linked to disease pathogenesis. Furthermore, using a murine hypomorph model of Matriptase deficiency we showed that that loss of Matriptase leads to increased disease susceptibility and failure to recover from a murine model of experimental colitis. I have recently discovered that Matriptase requires proteolytic activation by another upstream membrane-anchored protease, called Prostasin, before it can induce intestinal barrier formation, suggesting the existence of a novel proteolytic pathway in this tissue. My current research focuses on the mechanisms by which Matriptase function is regulated, and in the identification of the downstream molecules which are regulated by Matriptase to induce intestinal barrier function.

Awards and Affiliations

FASEB SRC Poster Award for outstanding poster presentation at the FASEB SRC Proteases in Hemostasis & Vascular Biology conference, 2015, Keystone, CO.

Professional Activity

Service activities

  • Co-organizer of the Center for Vascular and Inflammatory Diseases (CVID) Seminar Series, University of Maryland
  • Ad hoc reviewer for Journal of Biological Chemistry
  • Ad hoc reviewer for American Journal of Physiology
  • Ad hoc reviewer for Journal of Investigative Dermatology
  • Ad hoc reviewer for Immunology and Cell Biology
  • Ad hoc reviewer for PlosOne

Teaching activities

  • Daily laboratory supervision and mentoring of doctoral candidates:
    • Gregory Conway
    • Tierra Johnson
    • Raymond Peroutka
    • Nisha Pawar
  • Associate Member of the Graduate Faculty of the University of Maryland Graduate School, Dec 2014-present
  • Thesis advisory committee member for Gregory Conway and Raymond Peroutka, Molecular Medicine Program, GPILS, Dec 2015- present