Laboratory of Dr. Keith L. Knutson
The overarching goals of the research program of Dr. Knutson are three-fold:
- to develop vaccine approaches to treat and prevent breast and ovarian cancer
- to identify mechanisms by which tumors evade immune destruction
- to translate novel innovative immune based approaches into patients
Several different foci of research are currently being pursued as described in Figure 1 (Some examples are described below):
Identifying self-tumor antigens and determining mechanisms by which natural tolerance can be overcome (Immune mechanisms).
- Developing platforms/methods to effectively generate immunity against self-antigens in the appropriate epithelial environments (Vaccines/Antibodies).
- To determine the optimal methods for detecting immune responses that correlate with protection (Immune measures).
- To determine pathways to immune resistance, including tumor recruitment of regulatory cells and immune induction of resistant tumor cell populations (Cancer structure).
- To integrate the above research areas into effective solutions for patient (Clinical trials).
Project 1. Identifying self-tumor antigens and determining mechanisms by which natural tolerance can be overcome.
Tolerance to self-antigens is mediated through the generation of antigen-specific regulatory T cells that recognize select epitopes of self-antigens. These epitopes need to be avoided in order to maximize the ability to generate immune responses. The laboratory is identifying immunogenic epitopes within several antigens for formulation into vaccine. Figure 2 shows highly immunogenic epitopes within HER-2/neu. Other antigens being explored as potential antigens for breast and ovarian cancers include ADMR, Folate receptor alpha, Axl kinase and IGFBP2. In addition to identifying antigens, other studies are looking at immune mechanisms that regulate immunity against self including PD-1 and B7-H1 interactions. Blockade of PD-1 enhances CD8 T cell immunity resulting in enhanced antitumor activity (Figure 3).
Project 2. Developing platforms/methods to effectively generate immunity against self-antigens in the appropriate epithelial environments.
One of the central goals of the laboratory is to develop immune responses that can naturally migrate to mucosal tissues where most tumors develop. Those efforts include understanding the natural trafficking patterns of CD8 T cell subsets to mammary and reproductive tissues. Our laboratory collaborates with the various infectious disease laboratories within VGTI to develop viral based vaccine approaches that stimulate high level mucosal immunity.
Project 3. To determine the optimal methods for detecting immune responses that correlate with disease.
The identification of biomarkers of disease protection is a critical challenge in immunotherapy and vaccinology. Several efforts are being developed. For example, Dr. Knutson’s group leads a group of scientists investigating the vaccinal effects of trastuzumab in HER-2/neu+ breast cancer patients. That work is evaluating whether or not trastuzumab induces an endogenous immune antitumor immune response in patients and whether that immune response is important to the enhanced relapse free survival these patients experience following treatment with the monoclonal antibody.
Project 4. To determine pathways to immune resistance, including tumor recruitment of regulatory cells and immune induction of resistant tumor cell populations.
Immune-induced cellular reprogramming (e.g. epithelial to mesenchymal transition) is being evaluated. In prior work, we have shown that exposure of breast cancer cells to immune effectors results in induction of epithelial to mesenchymal transition generating cells with a breast cancer stem cell phenotype. Further studies in this model have revealed that breast cancer cells are plastic in terms of their differentiation state and can assume a few different phenotypes, some of which are highly tumorigenic and resistant to immune killing (Figure 5). Ongoing work involves interrogation of potential immunogenic targets expressed during the various differentiation states in order to optimize vaccine efficacy. Other studies in the laboratory evaluate the role of immune suppressor cells within the tumor microenvironment (Figure 6). This work focuses on the identification of pathways associated with trafficking into tumor as well as identification of targets that can be used to eliminate these cells.
Project 5. To integrate the above research areas into effective solutions for patient.
The primary interest of Dr. Knutson’s group is to make a difference for patients. Dr. Knutson currently has three Phase I cancer vaccine clinical trials at various stages of development. Two have been approved by FDA and are currently recruiting patients. Both trials focus on assessing safety and immunogenicity as primary outcomes. One vaccine (IND 14546), targets a novel antigen, the folate receptor alpha. A unique and innovative feature of this vaccine trial is that patients will be pretreated with a Treg depleting drug, cyclophosphamide. The second vaccine (IND 14749), targets HER-2/neu, an antigen that is present on 20%-30% of breast cancer. The vaccine is administered to HER-2/neu-overexpressing breast cancer patients following adjuvant combination chemo- and trastuzumab therapy.
Keith L Knutson, Ph.D.
Program Director and
Vaccine & Gene Therapy Institute
9801 SW Discovery Way
Port St. Lucie, FL 34987
Tel: (772) 345-5694
Fax: (772) 345-0625
Tel: (772) 345-5717
Fax: (772) 345-5768
Kumar Karyampudi, Ph.D. -
Shaun White -
Puru Lamichhane -
- Goode EL, DeRycke M, Kalli KR, Oberg AL, Cunningham JM, Maurer MJ, Fridley BL, Armasu SM, Serie DJ, Ramar P, Goergen K, Vierkant RA, Rider DN, Sicotte H, Wang C, Winterhoff B, Phelan CM, Schildkraut JM, Weber RP, Iversen E, Berchuck A, Sutphen R , Birrer MJ, Hampras S, Preus L, Gayther SA, Ramus SJ, Wentzensen N, Yang HP, Garcia-Closas M, Song H, Tyrer J, Pharoah PPD, Konecny G, Sellers TA, Ness RB, Sucheston LE, Odunsi K, Hartmann LC, Moysich KB, and Knutson KL, 2013, Inherited Variants in Regulatory T Cell Genes and Outcome of Ovarian Cancer, PLOS One 8(1):e53903.
- Henle A, Erskine CL, Clynes R, Benson L, Knutson KL. 2012, Enzymatic discovery of a HER-2/neu epitope that generates cross-reactive T cells. J Immunol 190(1):479-88.
- Krempski J, Karyampudi L, Behrens MD, Erskine CL, Hartmann L, Dong H, Goode EL, Kalli KR, Knutson KL. 2011, Tumor-infiltrating programmed death receptor-1+ dendritic cells mediate immune suppression in ovarian cancer. J Immunol 186(12):6905-6913.
- Santisteban M, Reiman JM, Asiedu M, Manjili MH, Ingle J, Hartmann L, Kalli KR, and Knutson KL, 2009, Immune-mediated induction of epithelial to mesenchymal transition generates the breast cancer stem cell phenotype. Cancer Res. 69:2887-2895.
- White KL, Vierkant RA, Phelan CM, Fridley BL, Anderson S, Knutson KL, Schildkraut JM, Cunningham JM, Kelemen LE, Pankratz VS, Rider DN, Liebow M, Hartmann LC, Sellers TA, and Goode EL. 2009 Polymorphisms in NF-kappaB Inhibitors and Risk of Epithelial Ovarian Cancer. BMC Cancer. 9:170, doi:10.1186/1471-2407-9-170.
- Basal E, Eghbali-Fatourechi G Z, Kalli KR, Hartmann LC, Goodman KM, Goode EL, Kamen BA, Low PS, and Knutson KL, 2009, Functional folate receptor alpha is elevated in the blood of ovarian cancer patients. PLoS ONE. 4:e6292.
- Sinicrope FA, Rego RL, Ansell SM, Knutson KL, Foster NR, Sargent DJ, 2009, A low intraepitheolial effector (CD3(+))/Regulatory (FoxP3(+)) T-cell ratio predicts adverse outcome of human colon carcinoma. Gastroenterology 137(4):1270-1279.
- Morales JK, Kmeciak M, Knutson KL, Bear HD, and Manjili MH, 2010, GM-CSF is one of the main breast tumor-derived soluble factors involved in the differentiation of CD11b-GR1-bone marrow progenitor cells into myeloid-derived suppressor cells. Breast Cancer Res Treat. 123(1):39-49.
- Karyampudi, L, Krco CJ, Kalli KR, Erskine CL., Hartmann LC, Goodman, Ingle JN, Maurer MJ, Nassar A, Yu C, Disis ML, Wettstein P., Fikes JD, Beebe M., Ishioka G, and Knutson KL, 2010, Identification of a broad coverage HLA-DR-degenerate epitope pool derived from carcinoembryonic antigen. Cancer Immunol Immunother. 59(1):161-171.
- Davis JM III, Knutson KL, Strausbauch MA, Crowson CS, Wettstein, PJ, Therneau TM, Matteson EL, Gabriel SE. 2010 Analysis of complex biomarkers for human immune-mediated disorders based on cytokine responsiveness of peripheral blood cells. J Immunol 184(12):7297-7304.
- Karyampudi L, Formicola C, Erskine CL, Maurer MJ, Ingle JN, Krco CJ, Wettstein, PJ, Kalli KR, Fikes JD, Beebe M, Hartmann LC, Disis ML, Ferrone S, Ishioka G, Knutson KL. A degenerate HLA-DR epitope pool of HER-2/neu reveals a novel in vivo immunodominant epitope, HER-2/neu88-102. Clin Cancer Res. 2010 Feb1;16(3):825-34.
- Asiedu MK, Ingle JN, Behrens MD, Radisky DC and Knutson KL, 2011, TGF?/TNF?-mediated epithelial to mesenchymal transition generates breast cancer stem cells with a claudin-low phenotype. Cancer Res. 71:4707-4719.
- Erskine CL, Krco CJ, Hedin KE, Borson ND, Kalli KR, Behrens MD, Heman-Ackah SM, von Hofe E, Wettstein PJ, Mohamadzadeh M, Knutson KL. 2011, MHC Class II Epitope Nesting Modulates Dendritic Cell Function and Improves Generation of Antigen-Specific CD4 Helper T Cells. J Immunol. 187:316-24.