A survey of genes expressed in adults of the human hookworm, Necator americanus

J. DAUB a1, A. LOUKAS a1p1, D. I. PRITCHARD a2 and M. BLAXTER a1c1
a1 Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
a2 Division of Life Science, University of Nottingham, Nottingham NG7 2RD, UK


Hookworms are gut-dwelling, blood-feeding nematodes that infect hundreds of millions of people, particularly in the tropics. As part of a program aiming to define novel drug targets and vaccine candidates for human parasitic nematodes, genes expressed in adults of the human hookworm Necator americanus were surveyed by the expressed sequence tag approach. In total 161 new hookworm genes were identified. For the majority of these, a function could be assigned by homology. The dataset includes proteases, protease inhibitors, a lipid binding protein, C-type lectins, an anti-bacterial factor, globins and other genes of interest from a drug or vaccine development viewpoint. Three different classes of small, secreted proteins were identified that may be involved in the host–parasite interaction, including potential potassium channel blocking peptides. One third of the genes were novel. These included highly expressed, secreted (glyco)proteins which may be part of the excretory–secretory products of these important pathogens. Of particular interest are a family of 9 genes with similarity to the immunomodulatory protein, neutrophil inhibitory factor, that may play a role in establishing an immunocompromised niche for this successful parasite.

(Received May 14 1999)
(Revised August 7 1999)
(Accepted August 25 1999)

Key Words: expressed sequence tags; hookworm; Necator americanus; Ancylostoma duodenale; Caenorhabditis elegans; ASP.

c1 Corresponding author: Ashworth Laboratories, ICAPB, King's Buildings, University of Edinburgh, Edinburgh EH9 3JT, UK. Tel: +44 131 650 6760. Fax: +44 131 650 5450. E-mail:
p1 Present address: Molecular Parasitology Unit, Queensland Institute for Medical Research, Royal Brisbane Hospital, QLD 4029, Australia.