Is Necator americanus approaching a mutualistic symbiotic relationship with humans?
The hookworm Necator americanus establishes infections of impressive longevity in the immunologically hostile environment of its human host. In the process, it promotes pronounced T-helper 2 (Th2) cell activity, which in turn seemingly affords the host at least a degree of protection. Given the relatively asymptomatic nature of infection, we argue here that Necator americanus might be approaching a mutualistic symbiotic relationship with humans. In our view, infection is controlled by the immune system while being supported by a subtle immune-evasion strategy that is tolerated and possibly beneficial to the host in certain immunological circumstances, such as in counterbalancing potentially damaging Th1 responses.
Boots Science Institute, School of Pharmaceutical Sciences, University of Nottingham, University Park, NG7 2RD, Nottingham, UK. pazdp@gwmail.nottingham.ac.uk
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Pritchard
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Brown
D000595:Amino Acid Sequence; D000818:Animals; D015801:Helminth Proteins / Q000737:chemistry; D006790:Host-Parasite Interactions; D006801:Humans; D008969:Molecular Sequence Data; D017221:Necator americanus / Q000502:physiology*; D009332:Necatoriasis / Q000276:immunology / Q000469:parasitology*; D013559:Symbiosis
D015801:Helminth Proteins