The objective of this project is to study the developmental biology and molecular interaction of human pathogenic Leishmania in phlebotomine sand flies, and to determine the biological potential of these host-parasite associations in disease transmission. The ultrastructural morphology and developmental sequence of parasites in the sand fly gut, as well as attachment mechanisms to gut linings will be compared in natural and unnatural hosts. The role of the peritrophic membrane in influencing sand fly susceptibility to Leishmania will be studied, including membrane formation, fine structure, interaction with parasites, and chemical composition. The cytochemistry of the sand fly gut will be investigated to help elucidate whether or not parasite interaction with epithelial linings is lectin-mediated. Lectins will be isolated from the gut epithelium and characterized. The carbohydrate composition of microvillar- and cuticle-lined surfaces of the gut will be compared in refractory and susceptible sand fly hosts. The possible inhibitory effects of specific carbohydrates and lectins on parasite attachment, multiplication, and morphogenesis in the sand fly gut will be studied in vitro and in vivo. Methodology to be used in this research project includes experimental infection of sand flies, histology and histochemistry, light and transmission electron microscopy, electron microscopic cytochemistry, and biological assays.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29AI028003-02
Application #
3455165
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1988-08-01
Project End
1993-07-31
Budget Start
1989-08-01
Budget End
1990-07-31
Support Year
2
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of Alaska Fairbanks
Department
Type
Organized Research Units
DUNS #
615245164
City
Fairbanks
State
AK
Country
United States
Zip Code
99775
Walters, L L; Irons, K P; Guzman, H et al. (1995) Peritrophic envelopes of Lutzomyia spinicrassa (Diptera: Psychodidae). J Med Entomol 32:711-25
Guzman, H; Walters, L L; Tesh, R B (1994) Histologic detection of multiple blood meals in Phlebotomus duboscqi (Diptera: Psychodidae). J Med Entomol 31:890-7
Walters, L L; Irons, K P; Chaplin, G et al. (1993) Life cycle of Leishmania major (Kinetoplastida: Trypanosomatidae) in the neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae). J Med Entomol 30:699-718
Walters, L L; Irons, K P; Guzman, H et al. (1993) Formation and composition of the peritrophic membrane in the sand fly, Phlebotomus perniciosus (Diptera: Psychodidae). J Med Entomol 30:179-98
Walters, L L (1993) Leishmania differentiation in natural and unnatural sand fly hosts. J Eukaryot Microbiol 40:196-206
Walters, L L; Irons, K P; Modi, G B et al. (1992) Refractory barriers in the sand fly Phlebotomus papatasi (Diptera: Psychodidae) to infection with Leishmania panamensis. Am J Trop Med Hyg 46:211-28
Walters, L L; Modi, G B; Chaplin, G L et al. (1989) Ultrastructural development of Leishmania chagasi in its vector, Lutzomyia longipalpis (Diptera: Psychodidae). Am J Trop Med Hyg 41:295-317