Immune recognition of Onchocerca volvulus proteins in the human host and animal models of onchocerciasis

J Helminthol. 2015 May;89(3):375-86. doi: 10.1017/S0022149X14000224. Epub 2014 Apr 10.

Abstract

Onchocerca volvulus is a tissue-dwelling, vector-borne nematode parasite of humans and is the causative agent of onchocerciasis or river blindness. Natural infections of BALB/c mice with Litomosoides sigmodontis and of cattle with Onchocerca ochengi were used as models to study the immune responses to O. volvulus-derived recombinant proteins (OvALT-2, OvNLT-1, Ov103 and Ov7). The humoral immune response of O. volvulus-infected humans against OvALT-2, OvNLT-1 and Ov7 revealed pronounced immunoglobulin G (IgG) titres which were, however, significantly lower than against the lysate of O. volvulus adult female worms. Sera derived from patients displaying the hyperreactive form of onchocerciasis showed a uniform trend of higher IgG reactivity both to the single proteins and the O. volvulus lysate. Sera derived from L. sigmodontis-infected mice and from calves exposed to O. ochengi transmission in a hyperendemic area also contained IgM and IgG1 specific for O. volvulus-derived recombinant proteins. These results strongly suggest that L. sigmodontis-specific and O. ochengi-specific immunoglobulins elicited during natural infection of mice and cattle cross-reacted with O. volvulus-derived recombinant antigens. Monitoring O. ochengi-infected calves over a 26-month period, provided a comprehensive kinetic of the humoral response to infection that was strictly correlated with parasite load and occurrence of microfilariae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth / blood*
  • Antigens, Helminth / immunology*
  • Cattle
  • Disease Models, Animal*
  • Helminth Proteins / immunology*
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Longitudinal Studies
  • Mice, Inbred BALB C
  • Onchocerca volvulus / immunology*
  • Onchocerciasis / immunology*
  • Onchocerciasis / pathology*
  • Parasite Load

Substances

  • Antibodies, Helminth
  • Antigens, Helminth
  • Helminth Proteins
  • Immunoglobulin G
  • Immunoglobulin M