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Scott Wetzel, Associate Professor

Office
Location: Charles H. Clapp Building, Room 216

Contact
Phone: 406-243-2168
Email: scott.wetzel@umontana.edu


Education

B.A. University of La Verne, La Verne, CA., 1987

M.S. California State Polytechnic University, Pomona, 1992

Ph.D. Oregon Health & Science University, Portland, OR, 2001

Teaching Experience

1996 - 2004     Instructor, Medical School Immunology, Oregon Health & Science University, Portland, OR

1997 - 2004     Instructor, Clinical Laboratory Science Program, Oregon Health & Science University, Portland, OR

2002 – 2004    Instructor, Biotechnology Department, Portland Community College, Portland, OR

2002 – 2011    Faculty Member, Annual International Course on 3D Microscopy of Living Cells, University of British Columbia, Vancouver, BC, Canada

Research Interests

Work in my lab focuses on antigen recognition and activation of CD4+ T lymphocytes.

CD4+ T lymphocytes recognize antigenic peptide fragments presented on the surface of antigen presenting cells (APC) by major histocompatiblility complex (MHC) class II proteins. Triggering of the T cell antigen receptor (TCR) by binding to the MHC:peptide ligand induces dramatic morphological changes as the T cell flattens against the APC and increases contact area forming stable T-APC conjugates. This initial antigen recognition is followed by large-scale spatial and temporal molecular rearrangements of plasma membrane proteins and intracellular signaling molecules. These rearrangements lead to the formation of an ordered structure at the T-APC interface termed the immunological synapse. The synapse is involved in T cell signaling as well as the site for delivery of T cell effector functions. We have previously shown that molecules from the APC are transferred to the T cell across the immune synapse in a process called trogocytosis.

 

Work in our lab focuses on two important areas related to T lymphocyte biology:

•  The biological consequences for individual T cells after the capture of APC membrane fragments from T-APC immunological synapse, a process termed “trogocytosis”;

•  The impact of the herbicide Atrazine on the activation of CD4+ T cells and the mechanism underlying a significant increase in Foxp3+ regulatory T cells

 

Trogocytosis 

We are examining the biological significance of intercellular transfer of molecules from APC to T cells (termed trogocytosis). We have previously shown that upon dissociation from APC, T cells capture MHC:peptide molecules from the immunological synapse and imaging data suggests that these molecules continue to signal to the T cell. Our work suggests that these trogocytosed molecules sustain intracellular signaling leading to selective survival of the trogocytosis positive cells, in vitro.  We are currently investigating whether this signaling influences effector subset differentiation and effector cytokine production. Our working hypothesis is that trogocytosis contributes to control of the immune response by sustaining cell-autonomous signaling resulting in sustained effector cytokine production and skewing of CD4+ T cells to a TH2-like phenotype. 

 

Immunotoxicology of Atrazine

We are examining the impact on Atrazine on thethe activation and differentiation of CD4+ T cells.  Atrazine is a very widely applied herbicide that the USGS  estimates contaminates 70% of the ground water in the US. It has been linked to birth defects,  cancer, immune developmental defects and  modulation of immune cell effector functions. We have shown that Atrazine inhibits lymphocyte proliferation and lymphocyte effector function.  In addition, we have shown that the frequency of Foxp3 positive regulatory T cells doubles in atrazine-treated cultures. We have recently found that male and female T cells repsonde differently to atrazine exposure.  We are now examining the impact of Atrazine-induced elevated estrogen on the induction of Tregs and Atrazine-associated inhibion of T cell activation.

Field of Study

Cellular Immunology

Courses

BIOB 410 - Immunology

BIOB 411 - Immunology Lab

BIOB 502 - Advanced Immunology

BIOM 596 - Principles of Light Microscopy

Publications

Thueson, L.E; Emmons, .E., Browning, D.B., Kreitinger, J.M.; Sheherd, D.M.; Wetzel S.A.  (2015). In vitro Exposure To The Herbicide Atrazine Inhibits T Cell Activation, Proliferation, and Cytokine Production and Significantly Increases The Frequency Of Foxp3+ Regulatory T Cells. Toxicological Sciences. 143:418-29. PMID: 25433234

Osborne, D.G. and Wetzel, S.A. (2012) Trogocytosis leads to sustained signaling in CD4+ T cells. The Journal of Immunology, 189(10):4728-39.  PMID: 23066151

Doherty, M., Osborne, D.G., Browning, D.B., Parker, D.C. Wetzel, S.A. (2010) Anergic CD4+ T cells form mature immunological synapses with enhanced accumulation of c-Cbl and Cbl-b. The Journal of Immunology, 184:3598-3608.  PMCID: PMC2843782

Thauland, T.J.; Y. Koguchi, R.Varma, S.A. Wetzel, M.L. Dustin, and D.C. Parker. (2008).  TH1 and TH2 cells fom morphologically distinct immunological synapses .  The Journal of Immunology,  181:393-9

Blake, D.J.; Wetzel, S.A.; Jean C Pfau, J.C. (2008) Autoantibodies from mice exposed to Libby amphibole asbestos bind SSA/Ro52-enriched apoptotic blebs of murine macrophages. Toxicology, 246:172-9

Scott A. Wetzel and D.C. Parker. (2006) MHC transfer from APC to T cells following antigen recognition. Critical Reviews in Immunology. 26:1-21

Tara J. Dillon, K.D.Carey, S.A. Wetzel, D.C. Parker, P.J.S. Stork. (2005). Regulation of the Small GTPase Rap1 and Extracellular Signal-Regulated Kinases by the Costimulatory Molecule CTLA-4. Molecular Cell Biology, 25(10):4117-4128

Scott A. Wetzel, T. W. McKeithan, D.C. Parker. (2005). Peptide-specific intercellular transfer of MHC class II to CD4+ T cells directly from the immunological synapse upon cellular dissociation. The Journal of Immunology. 174(1): 80-9

Tara J. Dillon, Vladimir Karpitski, Scott A. Wetzel, David C. Parker, Andrey S. Shaw, and Philip J. S. Stork (2003). Ectopic B-Raf expression enhances extracellular signal-regulated kinase (ERK) Signaling in T cells and prevents antigen presenting cell-induced anergy. Journal of Biological Chemistry, 278:35940.

Wetzel, S.A. ; McKeithan, T.W.; Parker D.C. (2002) Live Cell Dynamics and the Role of Costimulation in Immunological Synapse Formation. The Journal of Immunology. 169(11):6092

Sperry P.J.; Cua D.J.; Wetzel S.A.; Adler-Moore, J.A. (1998) Antimicrobial activity of AmBisome and non-liposomal Amphotericin B following uptake of Candida glabrata by murine epidermal Langerhans cells. Medical Mycology 36(3):135 - 141

Primus, F.J.; Finch, M.D.; Wetzel, S.A.; Masci, A.M.; Schlom, J.; Kashmiri, S.V.S. (1994) Monoclonal Antibody Gene Transfer: Implications for Tumor - Specific Cell - Mediated Cytotoxicity. Annals of the New York Academy of Science. 716:154 - 166