Vaccine-induced protection against murine schistosomiasis mansoni with larval excretory-secretory antigens and papain or type-2 cytokines

J Parasitol. 2013 Apr;99(2):194-202. doi: 10.1645/GE-3186.1. Epub 2012 Sep 17.

Abstract

Schistosoma mansoni glyceraldehyde 3-phosphate dehydrogenase (SG3PDH), peroxiredoxin (TPX), and other larval excretory-secretory products (ESP) essentially induce T helper (Th) 1 and Th17 immune responses during a non-protective natural infection. Such an immune environment promotes production of nitric oxide and hydrogen peroxide by interferon-γ-activated monocytes and interleukin (IL)-17-mediated recruitment and activation of neutrophils; however, it also likely prevents engagement of eosinophils and basophils in the hunt for developing larvae. We reasoned that polarizing ESP-induced immune responses toward a Th2 phenotype, via the use of cysteine proteases or type-2 cytokines, would lead to almost total parasite elimination. Accordingly, outbred mice were immunized with 10 μg recombinant SG3PDH and 15 μg TPX-derived peptide together with 10 μg papain, or 200 ng thymic stromal lymphopoietin, IL-25, or IL-33 as an adjuvant. Two weeks later, untreated mice, adjuvant controls, and immunized mice were challenged with 100 or 125 cercariae. Results of 6 experiments indicated that these formulations elicited IgM, IgG1, and IgA specific antibodies, and an increase in ex vivo spleen cells release of IL-4 and IL-5 correlated with highly significant (up to P < 0.0001) reduction of 62 to 78% in challenge worm burden. Improvement of ESP selection, singly or in a combination, and immunization regimen, namely ESP and type-2 cytokine dose and injection site and schedule, could lead to a sterilizing schistosomiasis vaccine in the foreseeable future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / classification
  • Animals
  • Antigens, Helminth / immunology*
  • Biomphalaria
  • Cytokines / classification
  • Cytokines / immunology*
  • Female
  • Larva / immunology
  • Male
  • Mice
  • Papain / immunology*
  • Schistosoma mansoni / immunology*
  • Schistosomiasis mansoni / prevention & control*
  • Vaccines* / chemistry
  • Vaccines* / standards

Substances

  • Adjuvants, Immunologic
  • Antigens, Helminth
  • Cytokines
  • Vaccines
  • Papain