Dr Louisa Ashby, Our people, University of Otago, Christchurch

Senior Research Fellow

BSc(Hons)(Cant), PhD(UCL)

Email louisa.ashby@otago.ac.nz
Tel +64 3 378 6223

Research interests

Dr Louisa Ashby's research is focused on the biochemistry of the neutrophil, and in particular the enzymology of myeloperoxidase. This enzyme kills microbes by generating chlorine bleach, but during inflammation it can also damage healthy tissue.

She is also interested in the oxidation chemistry of myeloperoxidase in its microbicidal activity, and how to effectively inhibit the enzyme from causing oxidative stress in disease.

Affiliations

Publications

Ashby, L., Chan, L., Winterbourn, C., Woon, S.-T., Keating, P., Heller, R., … Chua, I., & Hsiao, K.-C. (2024). Phenotypic spectrum in a family with a novel RAC2 p.I21S dominant-activating mutation [Case report]. Clinical & Translational Immunology, 13, e1493. doi: 10.1002/cti2.1493 Journal - Research Other

Kettle, T., Dickerhof, N., Ford, D., Dilly, J. D., Ashby, L. V., Anderson, R. F., & Payne, R. J. (2023). Dioxygenation of tryptophan residues by superoxide and myeloperoxidase. Proceedings of the New Zealand Society for Biochemistry and Molecular Biology (NZSBMB) 50th Anniversary Conference. Retrieved from https://www.nzsbmb.org/conference Conference Contribution - Published proceedings: Abstract

Flannery, M., McKenzie, J., Ashby, L., & Kettle, T. (2023). Interactions between superoxide and myeloperoxidase inside phagocytic neutrophils. Proceedings of the New Zealand Society for Biochemistry and Molecular Biology (NZSBMB) 50th Anniversary Conference. Retrieved from https://www.nzsbmb.org/conference Conference Contribution - Published proceedings: Abstract

Paumann-Page, M., Ashby, L. V., Khalilova, I., Magon, N. J., Hofbauer, S., Paton, L. N., … Kettle, A. J. (2023). Hypochlorous acid inactivates myeloperoxidase inside phagocytosing neutrophils. Redox Biochemistry & Chemistry, 5-6, 100008. doi: 10.1016/j.rbc.2023.100008 Journal - Research Article

Ashby, L. V., Flannery, M., Chua, I., & Kettle, A. J. (2023). Measuring oxidant production in phagosomes to identify abnormalities in neutrophil function. Free Radical Biology & Medicine, 201(Suppl. 1), (pp. 13). doi: 10.1016/j.freeradbiomed.2023.03.072 Conference Contribution - Published proceedings: Abstract

2024

Journal - Research Other

2023

Journal - Research Article

Journal - Research Other

Kettle, A. J., Ashby, L. V., Winterbourn, C. C., & Dickerhof, N. (2023). Superoxide: The enigmatic chemical chameleon in neutrophil biology [Invited review]. Immunological Reviews, 314, 181-196. doi: 10.1111/imr.13183

Conference Contribution - Published proceedings: Abstract

2022

Journal - Research Article

Ashby, L. V., Springer, R., Loi, V. V., Antelmann, H., Hampton, M. B., Kettle, A. J., & Dickerhof, N. (2022). Oxidation of bacillithiol during killing of Staphylococcus aureus USA300 inside neutrophil phagosomes. Journal of Leukocyte Biology, 112, 591-605. doi: 10.1002/jlb.4hi1021-538rr

Conference Contribution - Poster Presentation (not in published proceedings)

Ashby, L. V., Dickerhof, N., Springer, R., Hampton, M. B., & Kettle, A. J. (2022, August). Bacterial resistance to oxidants in neutrophil phagosomes. Poster session presented at the Webster Centre for Infectious Diseases Satellite Meeting: Queenstown Research Week, Queenstown, New Zealand.

2021

Journal - Research Article

Königstorfer, A., Ashby, L. V., Bollar, G. E., Billiot, C. E., Gray, M. J., Jakob, U., Hampton, M. B., & Winterbourn, C. C. (2021). Induction of the reactive chlorine-responsive transcription factor RclR in Escherichia coli following ingestion by neutrophils. Pathogens & Disease, 79, ftaa079. doi: 10.1093/femspd/ftaa079

Conference Contribution - Published proceedings: Abstract

Kettle, A. J., Ashby, L. V., Das, A. B., Dickerhof, N., Hampton, M. B., & Winterbourn, C. C. (2021). What's so super about superoxide? Proceedings of the 16th Congress of the Federation of Asian & Oceanic Biochemists & Molecular Biologists (FAOBMB). (pp. 275). Retrieved from https://www.faobmb2021.org

2020

Chapter in Book - Research

Magon, N. J., Parker, H. A., Ashby, L. V., Springer, R. J., & Hampton, M. B. (2020). Analysis of neutrophil bactericidal activity. In M. T. Quinn & F. R. DeLeo (Eds.), Neutrophil: Methods and protocols: Methods in molecular biology (Vol. 2087). (3rd ed.) (pp. 149-164). New York, NY: Humana Press. doi: 10.1007/978-1-0716-0154-9_12

Journal - Research Other

Ashby, L. V., Springer, R., Hampton, M. B., Kettle, A. J., & Winterbourn, C. C. (2020). Evaluating the bactericidal action of hypochlorous acid in culture media. Free Radical Biology & Medicine, 159, 119-124. doi: 10.1016/j.freeradbiomed.2020.07.033

Conference Contribution - Published proceedings: Abstract

Hsiao, K.-C., Caldwell, I., Woon, S. T., & Ashby, L. (2020). Novel heterozygous dominant activating RAC2 variant in four New Zealand patients with combined immunodeficiency. Journal of Clinical Immunology, 40(Suppl. 1), (pp. S120-S121). doi: 10.1007/s10875-020-00764-z

2018

Chapter in Book - Research

Forbes, L. V., & Kettle, A. J. (2018). Myeloperoxidase: Unleashing the power of hydrogen peroxide. In M. C. M. Vissers, M. B. Hampton & A. J. Kettle (Eds.), Hydrogen peroxide metabolism in health and disease. (pp. 281-304). Boca Raton, FL: CRC Press.

Journal - Research Article

Turner, R., Brennan, S. O., Ashby, L. V., Dickerhof, N., Hamzah, M. R., Pearson, J. F., Stamp, L. K., & Kettle, A. J. (2018). Conjugation of urate-derived electrophiles to proteins during normal metabolism and inflammation. Journal of Biological Chemistry, 293(51), 19886-19898. doi: 10.1074/jbc.RA118.005237

Albrett, A. M., Ashby, L. V., Dickerhof, N., Kettle, A. J., & Winterbourn, C. C. (2018). Heterogeneity of hypochlorous acid production in individual neutrophil phagosomes revealed by a rhodamine-based probe. Journal of Biological Chemistry, 293(40), 15715-15724. doi: 10.1074/jbc.RA118.004789

Coker, M. S., Forbes, L. V., Plowman-Holmes, M., Murdoch, D. R., Winterbourn, C. C., & Kettle, A. J. (2018). Interactions of staphyloxanthin and enterobactin with myeloperoxidase and reactive chlorine species. Archives of Biochemistry & Biophysics, 646, 80-89. doi: 10.1016/j.abb.2018.03.039

Forbes, L. V., & Kettle, A. J. (2018). A multi-substrate assay for finding physiologically effective inhibitors of myeloperoxidase. Analytical Biochemistry, 544, 13-21. doi: 10.1016/j.ab.2017.12.022

Conference Contribution - Published proceedings: Abstract

Albrett, A. M., Ashby, L. V., Dickerhof, N., Hampton, M. B., Winterbourn, C. C., & Kettle, A. J. (2018). Detection of hypochlorous acid in neutrophil phagosomes with the probe R19S: Chlorinated product formation and real-time fluorescence. Proceedings of the New Zealand Microbiological Society (NZMS) New Zealand Society for Biochemistry and Molecular Biology (NZSBMB) Joint Annual Conference: Microbes & Molecules. (pp. 112-113). Retrieved from https://www.nzmsconference.org.nz

Conference Contribution - Poster Presentation (not in published proceedings)

Springer, R., Ashby, L., Kettle, A., Winterbourn, C., & Hampton, M. (2018, September). Staphylococcus Aureus survival inside the neutrophil phagosome. Poster session presented at the Otago Spotlight Symposium on Infectious Disease, Wellington, New Zealand.

2017

Conference Contribution - Verbal presentation and other Conference outputs

Forbes, L. V., Konigstorfer, A., Gray, M. J., Jakob, U., Kettle, A. J., Hampton, M. B., & Winterbourn, C. C. (2017, July). Bacterial resistance to neutrophil-derived oxidants. Verbal presentation at the New Zealand Branch of the Australasian Society for Immunology (NZ ASI) Annual Scientific Meeting, Christchurch, New Zealand.

2014

Journal - Research Article

Stamp, L. K., Turner, R., Khalilova, I. S., Zhang, M., Drake, J., Forbes, L. V., & Kettle, A. J. (2014). Myeloperoxidase and oxidation of uric acid in gout: Implications for the clinical consequences of hyperuricaemia. Rheumatology, 53(11), 1958-1965. doi: 10.1093/rheumatology/keu218

Kettle, A. J., Albrett, A. M., Chapman, A. L., Dickerhof, N., Forbes, L. V., Khalilova, I., & Turner, R. (2014). Measuring chlorine bleach in biology and medicine. Biochimica et Biophysica Acta: General Subjects, 1840(2), 781-793. doi: 10.1016/j.bbagen.2013.07.004

Journal - Research Other

Carr, A., Pullar, J., Forbes, L., & Rosengrave, P. (2014). Working mothers are disadvantaged by limited funding for health research. New Zealand Medical Journal, 127(1398). Retrieved from http://www.nzma.org.nz/journal

Conference Contribution - Published proceedings: Abstract

Kettle, A., Albrett, A., Forbes, L., Parker, H., Turner, R., Pattemore, P., & Winterbourn, C. (2014). Bacterial killing and oxidant production by neutrophils from patients with cystic fibrosis. Free Radical Biology & Medicine, 76(Suppl. 1), (pp. S163). doi: 10.1016/j.freeradbiomed.2014.10.047

Conference Contribution - Poster Presentation (not in published proceedings)

Forbes, L. V., Parker, H., Turner, R., Albrett, A., & Kettle, A. J. (2014, December). Myeloperoxidase and protein oxidation in the neutrophil phagosome. Poster session presented at the Society for Free Radical Research Australasia 22nd Annual Scientific Meeting, Melbourne, Australia.

Conference Contribution - Verbal presentation and other Conference outputs

Kettle, A., Albrett, A., Forbes, L., Parker, H., Turner, R., Pattemore, P., & Winterbourn, C. (2014, November). Bacterial killing and oxidant production by neutrophils from patients with cystic fibrosis. Verbal presentation at the Society for Free Radical Biology and Medicine (SFRBM) 21st Annual Meeting, Seattle, WA.

2013

Journal - Research Article

Forbes, L. V., Sjögren, T., Auchère, F., Jenkins, D. W., Thong, B., Laughton, D., … Turner, R., … Kettle, A. J. (2013). Potent reversible inhibition of myeloperoxidase by aromatic hydromates. Journal of Biological Chemistry, 288(51), 36636-36647. doi: 10.1074/jbc.M113.507756

Conference Contribution - Published proceedings: Abstract

Forbes, L. V., Sjögren, T., Auchère, F., Thong, B., Eriksson, H., Unitt, J. F., & Kettle, A. (2013). Potent reversible inhibition of myeloperoxidase by aromatic hydroxamates. Free Radical Biology & Medicine, 65(Suppl. 2), (pp. S127). doi: 10.1016/j.freeradbiomed.2013.10.712

Conference Contribution - Verbal presentation and other Conference outputs

Forbes, L. V., Sjögren, T., Auchère, F., Jenkins, D. W., Thong, B., Laughton, D., … Kettle, A. J. (2013, August). Potent reversible inhibition of myeloperoxidase by aromatic hydroxamates. Verbal presentation at the Queenstown Molecular Biology (QMB) Meetings, Queenstown, New Zealand.

2012

Journal - Research Article

Forbes, L. V., Furtmüller, P. G., Khalilova, I., Turner, R., Obinger, C., & Kettle, A. J. (2012). Isoniazid as a substrate and inhibitor of myeloperoxidase: Identification of amine adducts and the influence of superoxide dismutase on their formation. Biochemical Pharmacology, 84(7), 949-960. doi: 10.1016/j.bcp.2012.07.020

2011

Journal - Research Article

Tidén, A.-K., Sjögren, T., Svensson, M., Bernlind, A., Senthilmohan, R., Auchère, F., … Forbes, L. V., Magon, N. J., Paton, L. N., Jameson, G. N. L., … Kettle, A. J. (2011). 2-Thioxanthines are mechanism-based inactivators of myeloperoxidase that block oxidative stress during inflammation. Journal of Biological Chemistry, 286(43), 37578-37589. doi: 10.1074/jbc.M111.266981

2010

Conference Contribution - Poster Presentation (not in published proceedings)

Forbes, L. V., & Kettle, A. J. (2010, November-December). Hydrazides as inhibitors of myeloperoxidase. Poster session presented at the Society for Free Radical Research (SFRR) Australasia 19th Annual Conference, Akaroa, New Zealand.

2003

Journal - Research Article

Briggs, C., Kunka, S., Pennaneach, C., Forbes, L., & Machin, S. J. (2003). Performance evaluation of a new compact hematology analyzer, the Sysmex pocH-100i. Laboratory Hematology, 9(4), 225-233.

2002

Journal - Research Article

Forbes, L. V., Gale, R. E., Pizzey, A., Pouwels, K., Nathwani, A., & Linch, D. C. (2002). An activating mutation in the transmembrane domain of the granulocyte colony-stimulating factor receptor in patients with acute myeloid leukemia. Oncogene, 21(39), 5981-5989. doi: 10.1038/sj.onc.1205767

1999

Journal - Research Article

Reeves, E. P., Dekker, L. V., Forbes, L. V., Wientjes, F. B., Grogan, A., Pappin, D. J. C., & Segal, A. W. (1999). Direct interaction between p47^phox and protein kinase C: Evidence for targeting of protein kinase C by p47^phox in neutrophils. Biochemical Journal, 344(3), 859-866. doi: 10.1042/0264-6021:3440859

Leino, L., Forbes, L., Segal, A., & Cockcroft, S. (1999). Reconstitution of GTPγS-induced NADPH oxidase activity in streptolysin-O-permeabilized neutrophils by specific cytosol fractions. Biochemical & Biophysical Research Communications, 265(1), 29-37. doi: 10.1006/bbrc.1999.1631

Forbes, L. V., Truong, O., Wientjes, F. B., Moss, S. J., & Segal, A. W. (1999). The major phosphorylation site of the NADPH oxidase component p67^phox is Thr²³³. Biochemical Journal, 338(1), 99-105. doi: 10.1042/0264-6021:3380099

Forbes, L. V., Moss, S. J., & Segal, A. W. (1999). Phosphorylation of p67^phox in the neutrophil occurs in the cytosol and is independent of p47^phox. FEBS Letters, 449(2-3), 225-229. doi: 10.1016/S0014-5793(99)00444-5

1998

Journal - Research Article

Abbott, W. G. H., Tan, P. L. J., Geursen, A., Fraser, J. D., Forbes, L., Simpson, I. J., … Skinner, M. A. (1998). TCRBV14S1 and rheumatoid arthritis revisited: Abnormalities in the percentage of transcribed TCRBV14S1 family genes in PBMC from rheumatoid arthritis patients. Scandinavian Journal of Rheumatology, 27, 68-75.

1996

Journal - Research Article

Willis, J. A., Scott, R. S., Brown, L. J., Forbes, L. V., Schmidli, R. S., Zimmet, P. Z., … Rowley, M. J. (1996). Islet cell antibodies and antibodies against glutamic acid decarboxylase in newly diagnosed adult-onset diabetes mellitus. Diabetes Research & Clinical Practice, 33(2), 89-97. doi: 10.1016/0168-8227(96)01281-8

1995

Journal - Research Article

Rudert, F., Visser, E., Forbes, L., Lindridge, E., Wang, L., & Watson, J. (1995). Identification of a silencer, enhancer, and basal promoter region in the human CD95 (Fas/APO-1) gene. DNA & Cell Biology, 14(11), 931-937.

Forbes, L. V., Scott, R. S., Brown, L. J., & Darlow, B. A. (1995). Immunogenetic, clinical and demographic characterization of childhood type 1 diabetes in New Zealand. Diabetes Care, 18(11), 1428-1433.

1994

Journal - Research Article

Rudert, F., Roos, M., Forbes, L., & Watson, J. (1994). Apoptosis in L929 cells expressing a CD40/Fas chimeric receptor: Dissociation of stimulatory from inhibitory death signalling functions. Biochemical & Biophysical Research Communications, 204(3), 1102-1110. doi: 10.1006/bbrc.1994.2576

1993

Journal - Research Article

Schmidli, R. S., Hagan, C., Scott, R. S., Livesey, J., & Forbes, L. V. (1993). Plasma proinsulin in recently diagnosed type 2 diabetes mellitus. Diabetes Research & Clinical Practice, 20(2), 133-138. doi: 10.1016/0168-8227(93)90007-R

Forbes, L. V., Brown, L. J., & Scott, R. S. (1993). HLA-DQβ typing and non-Asp57 alleles in IDDM and nondiabetic subjects in New Zealand. Diabetes Care, 16(8), 1179-1183.

1992

Journal - Research Article

Scott, R. S., Brown, L. J., Darlow, B. A., Forbes, L. V., & Moore, M. P. (1992). Temporal variation in incidence of IDDM in Canterbury, New Zealand. Diabetes Care, 15(7), 895-899. doi: 10.2337/diacare.15.7.895