Robert Wheeler, Ph.D.
Hitchner Hall Room 209
Twitter: Wheeler Lab@UMOWheelerLab
Email/web: Send an Email
Note that this page is not frequently updated.
Please check out the Lab Webpage: http://umaine.edu/wheelerlab/
AB (1993) Harvard College
PhD (2000) Stanford University
Post-doctoral: Whitehead Institute
Fungal host-pathogen interaction
There is an ongoing war between microbial pathogens and their hosts.For each mode of host immunity, the challenger has designed a defense, which in turn leads the host to devise a new avenue of attack. Opportunistic pathogens such as the fungus Candida, a leading cause of hospital-acquired infection and an increasingly important killer, must be able to constantly evade the attacks of the host and exploit any break in host defense caused by a compromise of immunity. The host, in turn, depends to a large part on innate immune responses to protect itself against this fungus. Using high throughput cell biology and genetics, we are elucidating this ongoing battle between fungi and host from both sides of the conflict.
Our work attacks fundamental biological questions that have clinical relevance. In the near term, we expect to understand the normal host-pathogen interaction in disease and during drug treatment. In the long term, we expect to identify new means to prevent and treat fungal infection through attacking the fungus and modulating immune response.
Microbial strategies for resisting immune attack
Candida is recognized by the innate arm of the immune system through evolutionarily conserved fungal surface molecules. Although innate immune cells can recognize several different surface molecules, the fungus can cover some molecules to tailor the immune response.
The sugar β-glucan is present throughout the cell wall of Candida, but as we discovered, the pathogen masks β-glucan from immune recognition to mute immune response. We discovered that a potent antifungal drug has an unexpected side-effect and can cause increased exposure of β-glucan in addition to killing fungi.We are devising and exploiting novel methodology to look at the clinical consequences of treating fungal infection with this antifungal drug.
We have recently begun using a transparent zebrafish model to probe host-pathogen interactions (Brothers et al. 2011, Tobin et al. 2012, Gratacap et al. 2013, Brothers et al. 2013). This model permits the real-time visualization of innate immune attack. Using this model, we have found that Candida-innate immune interactions differ in vivo from our expectations based on in vitro experiments. We are currently using this model to probe the cellular effects of loss of phagocyte NADPH oxidase function. In the future, this model holds promise for understanding the molecular mechanisms that regulate Candida interaction with innate immune cells, endothelial cells and epithelial cells.
Host strategies for clearing fungal pathogens
We have recently begun using a transparent zebrafish model to probe host-pathogen interactions (see Publications Webpage). This model permits the real-time visualization of innate immune attack. Using this model, we have found that Candida-innate immune interactions differ in vivo from our expectations based on in vitro experiments. We are currently using this model to probe the cellular effects of loss of phagocyte NADPH oxidase function. In the future, this model holds promise for understanding the molecular mechanisms that regulate Candida interaction with innate immune cells, endothelial cells and epithelial cells.
Host and pathogen determinants of infection spread and dissemination
Work from two recent PhD graduates shed light on both how the growth shape of Candida and host cells and processes combine to allow the non-motile fungus to move from tissue to tissue and spread the infection. Using transparent zebrafish, Brittany Seman discovered that only the yeast form of Candida can disseminate; the filamentous form instead damages tissue and causes death. Allison Scherer found that Candida can either use host macrophages as Trojan Horses to get to new areas of the host. In the absence of macrophages and neutrophils to attack it and move it around, Candida can also get through into the bloodstream and spread through the circulation. These complementary mechanisms of dissemination make Candida a successful pathogen in different host conditions.
Polymicrobial infections and their effect on antimicrobial drug action
Our recent published work has shown two surprising aspects of Candida interaction with the bacterial pathogen Pseudomonas aeruginosa. Surprisingly, we found that the microbes have enhanced virulence during co-infection of the zebrafish. This suggests that they can promote each other’s growth and virulence in the face of immune attack. But this enhanced virulence comes at a cost for the fungus, Candida, because it then becomes exquisitely sensitive to the antifungal drug fluconazole. In the presence of P. aeruginosa, fluconazole changes from a fungistatic to a fungicidal drug and kills the Candida instead of just slowing its growth. In the future, we plan to discover how P. aeruginosa causes this enhanced effect against Candida and which pathways it affects in the fungus.
Publications (current as of March 2022)
For most up-to-date information please check out our Google Scholar page:
- Hattab S.$, Dagher A.M.$$, Wheeler R.T. (accepted) Pseudomonas synergizes with fluconazole against Candida during treatment of polymicrobial infection. Immun. bioRxiv preprint: doi:https://doi.org/10.1101/2021.11.15.468768
- Ardizzoni A., Wheeler R.T. @, Pericolini E.@ (2021) It takes two to tango: how a dysregulation of the innate immunity, coupled with Candida virulence, triggers VVC onset. Microbiol. 12, 1449
- Harris-Lovett S.@, Nelson K.L., Beamer P., Bischel H.N., Bivins A., Bruder A., Butler C., Camenisch T.D., Susan K., Karthikeyan S., Larsen D.A., Meierdiercks K., Mouser P., Pagsuyoin S., Prasek S., Radniecki T.S., Ram J.L., Roper D.K., Safford H., Sherchan S.P., Shuster W., Stalder T., Wheeler R.T., Korfmacher K.S.@ (2021) Wastewater surveillance for SARS-CoV-2 on college campuses: Initial efforts, lessons learned and research needs. IJERPH. 18 (9), 4455
- Ardizzoni A., Sala A., Colombari B., Giva L., Cermelli C., Peppoloni S., Vecchiarelli A., Roselletti E., Blasi E., Wheeler R.T.@, Pericolini E.@ (2020) Perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) impair neutrophil candidacidal activity and are found in the cellular fraction of vaginal samples from women with vulvovaginal candidiasis. of Fungi. 6 (4), 225
- Scherer A.K. $, Blair B.A. $, Park J., Seman B.G. $, Kelley J.B., Wheeler R.T. @ (2020) Redundant Trojan horse and endothelial-circulatory mechanisms for host-mediated spread of Candida albicans PLoS Pathogens. 16 (8), e1008414
- Archambault L.S.$, Trzilova D.$$, Gonia S., Gale C., Wheeler R.T. (2019). Intravital imaging reveals divergent cytokine and cellular immune responses to Candida albicans and Candida parapsilosis. 10(3): e00266-19.
- Ho J., Yang X., Nikou S., Kichik N., Donkin A., Ponde N.O., Richardson J.P., Gratacap R.L., Archambault L.$, Zwirner C.P.$$, Murciano C., Henley-Smith R., Thavaraj S., Tynan C.J., Gaffen S.L., Hube B., Wheeler R.T., Moyes D.L. and NaglikR. (2019) Candidalysin activates epithelial innate immune responses via epidermal growth factor receptor (EGFR) Nature Comm. 10(2297).
- Petit J., Wheeler R.T., Bailey E.C.$$, Ferreira de Oliveira C.A., Forlenza M., Wiegertjes G.F. (2019) Studies into β-glucan recognition in fish suggests a key role for the C-type lectin pathway. Immunol. 10: 280.
- Rosowski E.E., Knox B.P., Archambault L.S.$, Huttenlocher A, Keller N.P., Wheeler R.T.* and Davis J.M.* (2018). The Zebrafish as a Model Host for Invasive Fungal Infections. Fungi 4 (4), 136.
- Wu Y., Du S., Johnson J.L., Tung H-Y., Landers C.T., Liu Y., Seman B.G.$, Wheeler R.T., Costa-Mattioli M., Kheradmand F., Zheng H. and Corry D.B. (2019) Microglia and Amyloid Precursor Protein Coordinate Control of Transient Candida Cerebritis With Memory Deficits. Nature Communications 10 (1), 58
- Pericolini E., Perito S., Castagnoli A., Gabrielli E., Mencacci A., Blasi E., Vecchiarelli A., Wheeler R.T. (2018) Epitope unmasking in vulvovaginal candidiasis is associated with hyphal growth and neutrophilic infiltration. PLoS One. 13 (7), e0201436.
- Seman B.G.$, Moore J.L.$$, Scherer A.K.$, Blair B.A.$, Manandhar S.$$, Jones J.M.$$, Wheeler R.T. (2018) Yeast and filaments have specialized, independent activities in a zebrafish model of Candida albicans Infect. Immun. 86 (10), e00415-18.
- Tucey T., Verma J., Harrison P., Snelgrove S., Lo T.L., Scherer A.K.$, Barugahare A., Powell D., Wheeler R.T., Hickey M.J., Beilharz T.H., Naderer T., Traven A. (2018) Glucose competition by a microbial pathogen drives immune cell death and fatal infections. Cell Metabolism. 27(5): 988–1006.e7
- Hopke A.$, Brown A.J.P., Hall R.A., Wheeler T. (2018). Dynamic fungal cell wall architecture in stress adaptation and immune evasion. Trends in Microbiology.
- **Bergeron A.C. $, Seman B.G. $, Hammond J.H., Archambault L.S. $, Hogan, D.A., Wheeler R.T. (2017). Candida albicans and Pseudomonas aeruginosa Interact To Enhance Virulence of Mucosal Infection in Transparent Zebrafish. Immun. Aug 28
- Gratacap R.L., Scherer A.K.$, Seman B.G.$, Wheeler R.T. (2017). Control of mucosal candidiasis in the zebrafish swimbladder depends on neutrophils that block filament invasion and drive extracellular trap production. Immun. Jun 12
- Gonia S., Archambault L.$, Shevik M., Altendahl M., Fellows E., Bliss J.M., Wheeler R.T. and Gale C.A. (2017). Candida parapsilosis Protects Premature Intestinal Epithelial Cells from Invasion and Damage by Candida albicans. Pediatr. Mar 22;5:54.
- Hopke A.$ and Wheeler R.T. (2017). In vitro detection of neutrophil traps and post-attack cell wall changes in Candida Bio-protocols. 7(7): e2213.
- Bergeron A.C.$, Barker S.E., Brothers K.M.$, Prasad B.C., Wheeler R.T. (2017) Polyclonal anti-Candida antibody improves phagocytosis and overall outcome in zebrafish model of disseminated candidiasis. Dev Comp Immunol. 68: 69-78.
- Hasim S., Allison D., Retterer S., Hopke A.$, Wheeler R.T., Doktycz M., and Reynolds T. (2016) ß-glucan unmasking in some Candida albicans mutants correlates with increases in cell wall surface roughness and decreases in cell wall elasticity. Infect Immun. Nov 14. pii: IAI.00601-16.
- Mallick E.M., Bergeron A., Jones Jr S.K.., Newman Z.R., Brothers K.M., Creton R., Wheeler R.T., and Bennett R.J. (2016) Phenotypic plasticity regulates Candida albicans interactions and virulence in the vertebrate host. Front. Microbiol. 7, 280.
- Hopke A., Nicke N., Hidu E.E., Degani G., Popolo L., and Wheeler R.T. (2016). Neutrophil Attack Triggers Extracellular Trap-Dependent Candida Cell Wall Remodeling and Altered Immune Recognition. PLoS Pathogens. May 25;12(5):e1005644.
- Leach M.D., Farrer R.A., Tan K., Miao Z., Walker L.A., Cuomo C.A., Wheeler R.T., Brown A.J.P., Wong K.H. and Cowen L.E. (2016) Global Analysis of Temperature-Dependent Control of Gene Expression, Chromatin Architecture and Virulence via Hsf1. Nat Commun. 2016 May 26;7:11704.
- Moyes D.L., Wilson D., Richardson J.P., Mogavero S., Tang S.X., Wernecke J., Höfs S., Gratacap R.L., Robbins J., Runglall M., Murciano C., Blagojevic M., Thavaraj S., Förster T.M., Hebecker B., Kasper L., Vizcay G., Iancu S.I., Kichik N., Häder A., Kurzai O., Luo T., Krüger T., Kniemeyer O., Cota E., Bader O., Wheeler R.T., Gutsmann T., Hube B. and Naglik J.R. (2016). Candidalysin: A fungal peptide toxin critical for mucosal infection. Nature. Mar 30. doi: 10.1038/nature17625.
- Voelz, K., Gratacap R.L., Wheeler R.T. (2015). A zebrafish larval model reveals early tissue-specific innate immune responses to Mucor circinelloides. Dis. Model. Mech. Nov;8(11):1375-88.
- Gratacap R.L., Bergeron A.C., Wheeler R.T. (2014). Modeling mucosal candidiasis in larval zebrafish by swimbladder injection. J. Vis. Exp. Issue 93: e52182.
- Gilbert A.S., Wheeler R.T., May R.C. (2014) Fungal Pathogens: Survival and Replication within Macrophages. Cold Spring Harb Perspect Med. 2014 Nov 10;5(7):a019661.
- Davis S.E., Hopke, A., Minkin, S.C. Jr., Montedonico, A.E., Wheeler, R.T., Reynolds, T.B. (2014). Masking of β(1-3)-glucan in the cell wall of Candida albicans from detection by innate immune cells depends on phosphatidylserine. Infect. Immun. 82(10):4405-13.
- Hogan, D.A., Wheeler, R.T. (2014). The complex roles of NADPH oxidases in fungal infection. Cell. Microbiol. 16(8):1156-1167.
- Gratacap RL^, Wheeler RT (2014) Exploitation of zebrafish to enable intravital study of eukaryotic pathogen-host interactions. Dev. Comp. Immunol. 46(1):108-115. Feb 1. pii: S0145-305X(14)00021-4.
- Lionakis MS, Swamydas M, Fischer BG, Plantinga TS, Johnson MD, Jaeger M, Masedunskas A, Weigert R, Mikelis C, Wan W, Lee CR, Lim JK, Yang JC, Laird GM, Wheeler RT, Alexander BD, Perfect JR, Gao J-L, Kullberg B-J, Netea MG, and Murphy PM (2013) Chemokine Receptor CX3CR1 Promotes Early Fungal Clearance and Survival in Systemic Candidiasis by Inhibiting Apoptosis of Kidney Resident Macrophages J. Clin. Invest. Dec 2;123(12):5035-51.
- Brothers KM**, Gratacap RL^, Barker SE^, Newman ZR**, Norum A*, Wheeler RT (2013) NADPH oxidase-driven phagocyte chemotaxis controls Candida albicans filamentous growth and prevents mortality. PLoS Pathog. 9(10):e1003634.
- Gratacap RL^, Rawls JF, Wheeler RT (2013) Mucosal candidiasis elicits activation of NF-κB, proinflammatory gene expression and localized neutrophilia in a transparent vertebrate mini-host. Disease Models & Mechanisms. Jul 4
- Marakalala MJ, Vautier S, Potrykus J, Walker LA, Shepardson KM, Hopke A**, Mora-Montes HM, Kerrigan A, Netea MG, Murray GI, MacCallum DM, Wheeler RT, Munro CA, Gow NAR, Cramer RA, Brown AJP and Brown GD (2013) Differential adaptation of Candida albicans in vivo modulates immune recognition by Dectin-1. PLoS Pathogens. 9(4): e1003315.
- Jiménez-López C, Collette JR, Brothers KM*, Shepardson KM, Cramer RA, Wheeler RT, Lorenz MC (2013) Candida albicans Induces Arginine Biosynthetic Genes in Response to Host-Derived Reactive Oxygen Species. Eukaryot. Cell. 2013; 12(1): p. 91-100
- Brothers, KM* and Wheeler, RT (2012) Non-invasive imaging of zebrafish larvae as a model of disseminated candidiasis. J Vis Exp. 30(65):pii 4051.
- Tobin, DM, May, RC, Wheeler, RT (2012) Zebrafish: a see-through host and a fluorescent toolbox to probe host-pathogen interaction. PLoS Pathog. 8(1):e1002349.
- Brothers K.M.*, Newman Z.R.*, Wheeler R.T. (2011) Live imaging of disseminated candidiasis in zebrafish reveals role of phagocyte oxidase in limiting filamentous growth. Eukaryot Cell. 2011 Jul; 10(7):932-44 Epub 2011 May 6. PMID: 21551247
- Moxley J.F., Jewett M.C., Antoniewicz M.R., Villas-Boas S.G., Alper H., Wheeler R.T., Tong L., Hinnebusch A.G., Ideker T., Nielsen J., Stephanopoulos G. (2009) Linking high-resolution metabolic flux phenotypes and transcriptional regulation in yeast modulated by the global regulator Gcn4p. Proc Natl Acad Sci U S A. 2009 Apr 21;106(16):6477-82.
- Johnnidis J.B., Harris M.H., Wheeler R.T., Stehling-Sun S., Lam M.H., Kirak O., Brummelkamp T.R., Fleming M.D. and Camargo F.D. (2008) Regulation of progenitor cell proliferation and granulocyte function by microRNA-223. Nature. Feb 28; 51(7182):1125-9.
- Wheeler R.T., Kombe D., Agarwala, S. and Fink G.R. (2008) Dynamic, morphotype-specific Candida albicans beta-glucan exposure during infection and drug treatment. PLoS Pathog. 2008 Dec;4(12):e1000227. Epub 2008 Dec 5. PMID:19057660.
- Wheeler R.T., Fink G.R. (2006) A drug-sensitive genetic network masks fungi from the immune system. PLoS Pathog. Apr;2(4):e35. Epub 2006 Apr 28.
- Wheeler, R. T., Kupiec, M., Magnelli, P., Abeijon, C. and Fink, G.R. (2003) A Saccharomyces cerevisiae mutant with increased virulence. Proc Natl Acad Sci U S A. 100(5):2766-70.
- Wheeler, R. T. and Shapiro, L. (1999) Differential localization of two histidine kinases controlling bacterial cell differentiation. Molecular Cell 4, 683-694
- Wheeler, R. T., Gober, J. W. and Shapiro, L. (1998) Protein localization during the Caulobacter crescentus cell cycle. Curr. Opin. Microbiol. 6, 636-642.
- Wheeler, R. T. and Shapiro, L. (1997) Bacterial Chromosome Segregation: Is There a Mitotic Apparatus? Cell 88, 577-579.
- Winzeler, E., Wheeler, R. and Shapiro, L. (1997) Transcriptional analysis of the Caulobacter 4.5S RNA ffs gene and the physiological basis of an ffs mutant with a Ts phenotype. J. Mol. Biol. 272(5), 665-676.
Selected Current and Recently Completed Grant Support (current as of March 2022)
- NIH/NIAID R15 (PI: Wheeler); Term 1/2018-12/2020; Title: Innate mucosal immunity to C. albicans in vivo. (NCE to 6/2022)
- Burroughs Wellcome Fund (Investigators in the Pathogenesis of Infectious Disease); (PI: Wheeler); Term: 7/2014-6/2019; Title: “Phagocytes block fungal dimorphism to defend the epithelial barrier” (NCE to 7/2022)
- MAFES/USDA Hatch (PI: Wheeler); Term: 10/2017-9/2022; Title: In vivo innate immune response to fungal infection