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

Hookworms are gut-dwelling, blood-feeding nematodes that infect hundreds of millions of people, particularly in the tropics. As part of a program aimi ng to define novel drug targets and vaccine candidates for human parasitic nematodes, genes expressed in adults of the human hookworm Necator american us were surveyed by the expressed sequence tag approach. In total 161 new h ookworm genes were identified. For the majority of these, a function could be assigned by homology. The dataset includes proteases, protease inhibitor s, a lipid binding protein, C-type lectins, an anti-bacterial factor, globi ns 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 potas sium channel blocking peptides. One third of the genes were novel. These in cluded highly expressed, secreted (glyco)proteins which may be part of the excretory-secretory products of these important pathogens. Of particular in terest are a family of 9 genes with similarity to the immunomodulatory prot ein, neutrophil inhibitory factor, that may play a role in establishing an immunocompromised niche for this successful parasite.