A number of important human parasitic diseases are transmitted by insect vectors. Organisms that cause diseases such as malaria or filariasis must evade or defeat the defensive responses of their insect vectors if successful transmission to human hosts is to take place. However, the cellular and molecular interactions between insects and such parasitic organisms are not well understood. In comparison with our detailed knowledge of the vertebrate immune system, the molecular mechanisms of insect immune responses remain largely a mystery. The primary response of insects to eukaryotic parasites is encapsulation of the invading organism by the host insect's hemocytes. The long term objective of this project is to identify and characterize proteins from insect hemocytes that are involved in the encapsulation process. We will approach this problem with the use of a unique panel of monoclonal antibodies to hemocytes of Manduca sexta that we have generated.
The specific aims are: 1) Identification of molecules within the vesicles of granular hemocytes or on the surface of plasmatocytes and granular hemocytes that are involved in hemocyte adhesion and encapsulation. We will screen our panel of monoclonal antibodies to find those that can disrupt plasmatocyte spreading, hemocyte adhesion, or encapsulation in in vitro assays. 2) Characterization of molecules identified in Aim 1. We will use the monoclonal antibodies that disrupt hemocyte responses as reagents to determine the size of the corresponding antigen, to purify the corresponding antigens, and to clone cDNAs for the corresponding antigens from hemocyte libraries. We will determine the sequences of the cDNAs and analyze the deduced amino acid sequences of the hemocyte proteins. The identification of proteins that function in hemocyte encapsulation is a first step toward understanding how they function and eventually toward understanding how parasites avoid the encapsulation response in insect vectors of human diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI031084-06
Application #
2667717
Study Section
Special Emphasis Panel (ZRG5-TMP (01))
Project Start
1992-07-01
Project End
1999-02-28
Budget Start
1998-03-01
Budget End
1999-02-28
Support Year
6
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Kansas State University
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
City
Manhattan
State
KS
Country
United States
Zip Code
66506
Rayaprolu, Subrahmanyam; Wang, Yang; Kanost, Michael R et al. (2010) Functional analysis of four processing products from multiple precursors encoded by a lebocin-related gene from Manduca sexta. Dev Comp Immunol 34:638-47
Suwanchaichinda, Chansak; Kanost, Michael R (2009) The serpin gene family in Anopheles gambiae. Gene 442:47-54
Kanost, Michael R; Jiang, Haobo; Yu, Xiao-Qiang (2004) Innate immune responses of a lepidopteran insect, Manduca sexta. Immunol Rev 198:97-105
Yu, Xiao-Qiang; Kanost, Michael R (2002) Binding of hemolin to bacterial lipopolysaccharide and lipoteichoic acid. An immunoglobulin superfamily member from insects as a pattern-recognition receptor. Eur J Biochem 269:1827-34
Yu, X-Q; Zhu, Y-F; Ma, C et al. (2002) Pattern recognition proteins in Manduca sexta plasma. Insect Biochem Mol Biol 32:1287-93
Wiegand, C; Levin, D; Gillespie, J et al. (2000) Monoclonal antibody MS13 identifies a plasmatocyte membrane protein and inhibits encapsulation and spreading reactions of Manduca sexta hemocytes. Arch Insect Biochem Physiol 45:95-108
Wang, Y; Jiang, H; Kanost, M R (1999) Biological activity of Manduca sexta paralytic and plasmatocyte spreading peptide and primary structure of its hemolymph precursor. Insect Biochem Mol Biol 29:1075-86
Yu, X Q; Kanost, M R (1999) Developmental expression of Manduca sexta hemolin. Arch Insect Biochem Physiol 42:198-212
Gillespie, J P; Kanost, M R; Trenczek, T (1997) Biological mediators of insect immunity. Annu Rev Entomol 42:611-43
Jiang, H; Wang, Y; Ma, C et al. (1997) Subunit composition of pro-phenol oxidase from Manduca sexta: molecular cloning of subunit ProPO-P1. Insect Biochem Mol Biol 27:835-50

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