Progress 10/01/04 to 09/30/07
Outputs
OUTPUTS: As indicated in previous years, I've been maintaining the hybridoma stocks and finishing up some minor work on this, but my main focus has been on mosquito ecology (since the year prior to the arrival of West Nile virus in the Tucson areas)
PARTICIPANTS: One master's student is now in his medical residency program. One undergraduate student is a senior scientist at a biotech firm in California. Another is a med tech at a local hospital. Another is now a practicing dentist. Another is applying for medical school after working for several years with NIH in Phoenix and currently working a research position on diabetes in Native Americans. I've lost track of a few others. I think all would say that I did an excellent job of training them to be independent thinkers, to check assumptions, and to be careful drawing conclusions.
TARGET AUDIENCES: Target audience for the immune response research was other researchers studying the immune response of insects in vitro.
PROJECT MODIFICATIONS: I did not believe I was being adequately heard in my field, West Nile was approaching Tucson, and it seemed like I might be a good person to address some of the mosquito issues. Also, personal considerations necessitated a temporary decrease in work hours that made the switch more appealing.
Impacts
My work clearly showed the importance of adding zinc to any in vitro experiments pertaining to the study of the immune response of lepidoptera. Unpublished, but widely disseminated work, also indicated the wide variation of response exhibited by different colonies of Manduca sexta.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Because of West Nile hitting Pima County I have mainly been working on mosquito-related problems this past year and have only been maintaining stock samples of hybridomas on the work of the immune response of insects, using Manduca sexta as a model.
Impacts
My work on mosquitoes has likely helped many people in the Tucson area and wider that have been concerned about mosquitoes and West Nile. In addition it led to initial funding for some work with faculty in Geography to study the geography (human and ecological) of mosquitoes in the Tucson area.
Publications
- Willott, E. 2006. Approaches to mosquito management in the southwest. Southwest Hydrology 5 (1) 24-25, plus 32.
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Progress 01/01/04 to 12/31/04
Outputs
Hung Tran will defend his master's thesis in April and we will submit a manuscript (draft available) for publication on his work; we have also made considerable progress on the immulectin 2 story. In addition, this last year saw publication of my Restoring Wetlands, Without Mosquitoes paper which has instigated conversations in many areas. This, along with my other work on Environmental Ethics, led to a Fulbright in Guatemala in October (2 weeks as a Senior Specialist) and consideration (will know more in April '05) for a 6 week Fulbright at Rhodes University in South Africa for July-August 2005.
Impacts
The mosquito work has had impact on both theoretical and practical levels. The theoretical work led to a publication which led to a New York Times article on my work, with follow-up articles in several trade publications and emails from literally all over the world. The practical focus of some of our research last year was driven by the West Nile virus situation in Arizona. Although this was not anticipated to occupy as much time as it did, we were able to provide scientific data that helped the county and state in their fight against West Nile. We identified the blood meals of Culex quinquefasciatus, helping emphasize its risk as a West Nile vector, and we documented a change in time of host-seeking behavior of Culex tarsalis, which permitted better targeting of adulticide operations.
Publications
- Willott, Elizabeth Restoring nature, without mosquitoes. Restoration Ecology 12 (2) 147-153, 2004.
- Zinser M., Ramberg F., and Willott E. Scientific Note: Culex quinquefasciatus (Diptera: Culicidae) as a potential West Nile virus vector in Tucson, Arizona: Blood meal analysis indicates feeding on both humans and birds. Journal of Insect Science. 2004. 4:20 (25 June 2004)
- Margaret Zinser. 2004. CULEX QUINQUEFASCIATUS HOST CHOICES IN RESIDENTIAL, URBAN TUCSON AND AT A CONSTRUCTED WETLAND. Master's Thesis, Entomology, The University of Arizona
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Progress 01/01/03 to 12/31/03
Outputs
This last year we completed experiments needed for revising two manuscripts, that are now being revised. We have confirmed, using flow cytometry, that more hemocytes bind the protein immulectin-2 when the hemocytes come from immune-activated larvae. We (Hung Tran) and myself also completed an extensive set of experiments on the effect of immune activation on the morphology of Manduca sexta hemocytes and the effect of the serine protease inhibitor TLCK on the morphology of Manduca sexta hemocytes either from immune-activated or control larvae. Using this and the work from earlier years, we submitted a proposal to NIH for further funding. In addition, as an offshoot of the work on mosquitoes, I finished an article on mosquitoes and restoration ecology which will appear this June.
Impacts
The work on mosquitoes and restoration ecology has already given rise to many stimulating discussions when I have presented it at UNC-Chapel Hill (Spring 2003) and at Ohio University (Fall 2003). I anticipate presenting it again at Duke (Spring 2004), and have included it in a prospectus to be a Fulbright scholar at Rhodes University South Africa for six weeks during summer 2005.
Publications
- Willott, E. Restoring nature, without mosquitoes. Restoration Ecology. Accepted. Expected publication date of June 2004.
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Progress 01/01/02 to 12/31/02
Outputs
(1) The study on calcium was published. Archives of Insect Biochemistry and Physiology 49: 187-202, 2002. (2) We completed the study on zinc and that was published. (3) We purified sufficient protein to generate sequence data on the two proteins (MS39 and MS17) we had been studying. Manuscripts on each of these were submitted but need revising and resubmission. For the work on MS17 we now have substantiated that the zinc protease thermolysin inhibits release of MS17 protein from granular cells.
Impacts
As noted last year, that zinc has such a significant effect on the activity of the immune cells suggests that people really need to include zinc when conducting in vitro assays. That thermolysin inhibits release of the immune-related protein MS17 again implicates zinc in the immune response.
Publications
- Willott, E., Tran, H.Q. (2002) Zinc and Manduca sexta hemocyte functions. Journal of Insect Science 2 (6) [online at insectscience.org/2.6]
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Progress 01/01/01 to 12/31/01
Outputs
(1) We completed the study on calcium, submitted and revised the manuscript and it is 'in press' with expected publication within a couple of months. (2) We extended the work to zinc with the supplemental assistance of a small grants to faculty award from the UofA, and tested whether endogenous zinc proteases are likely involved in the immune response of Manduca sexta. Our work indicates at least one, and more likely at least two zinc proteases are involved, for at least two different steps in the immune response. The manuscript on this work was submitted Jan 8, 2002 and is currently undergoing minor revisions with expected resubmission next week. (3) The work on two proteins released from hemocytes has continued (for protein MS39 recognized by monoclonal antibody MS39) and resumed for MS17 (recognized by monoclonal antibody MS17).
Impacts
(1) The zinc work should definitely influence how people do in vitro work on the immune response of insects. Zinc, at physiological concentrations, needs to be incorporated into buffers. (2) Identifying and characterizing proteins involved in the insect immune response is expected to shed light on why certain species or varieties respond in particular ways and not others.
Publications
- Willott, E, Hallberg, C.A., Tran, H.Q. (2002) The influence of calcium on Manduca sexta plasmatocyte spreading and network formation. Archives of Insect Biochemistry and Physiology (in press).
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Progress 01/01/00 to 12/31/00
Outputs
(1) We have been studying the effect of calcium and magnesium on Manduca sexta hemocyte functions. Calcium, but not magnesium, is required for Manduca sexta hemocytes to achieve elongated spreading on glass and to form a network of connecting hemocytes on plastic. A subpopulation of plasmatocytes (one type of hemocyte) in the presence of calcium elongate to a length/width ratio exceeding 6. The spreading response is dose-dependent over the range 0, 0.06, 0.6, 6 mM calcium. Higher levels of calcium were not tested because a precipitate forms if Grace's medium is made to 15 mM calcium. (2) From previous work we had identified a monoclonal antibody that recognized an antigen present more abundantly in hemolymph from Manduca sexta treated with bacteria than in hemolymph from control Manduca. The MAb also recognized an antigen more abundant in the supernatant of the Aedes albopictus cell line C7-10 when these cells are treated with bacteria than when they are not. We again
purified and attempted to generate good polyclonal antiserum against the protein. We refined our purification scheme for obtaining the protein from Manduca sexta hemolymph and our currently acquiring sufficient antigen to generate a polyclonal antiserum that can be used to screen a cDNA expression library. Immunofluorescence staining patterns are consistent with the antigen being involved in the immune-response of Manduca. (3) We also completed the paper writing for two publications on laboratory work previously done on the immune response of Manduca sexta.
Impacts
(1) People studying insect blood cells typically include EDTA in initial bleeding buffers. This prevents the cells from aggregating but it also can prevent them from spreading onto microscope slides if they remain in the EDTA-containing solution very long. Knowing what cell functions require calcium and which magnesium, and in what amounts, is basic knowledge that can help many researchers studying either hemolymph or hemocytes. From this we may be able to determine more specific ways of preventing unwanted reactions while not inhibiting other normal reactions. (2) Identifying proteins involved in the insect immune response is expected to shed light on why certain species or varieties respond particular ways and others do not.
Publications
- Meyer-Fernandes, J.R., Lanz-Mendoza, H., Gondim, K.C., Willott, E., Willott, M.A. 2000. Ectonucleotide diphosphohydrolase activities in hemocytes of larval Manduca sexta. Archives of Biochemistry and Biophysics 382 (1): 152-159.
- Wiegand, C., Levin, D., Gillespie, J.P., Willott, E., Kanost, M.R., Trenczek, T. 2000. Monoclonal antibody MS13 identifies a plasmatocyte membrane protein and inhibits encapsulation and spreading reactions of Manduca sexta hemocytes. Archives of Insect Biochemistry and Physiology 45: 95-108.
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