Potential of recombinant inorganic pyrophosphatase antigen as a new vaccine candidate againstBaylisascaris schroederiin mice
Xie Y, Chen S, Yan Y, Zhang Z, Li D, Yu H, Wang C, Nong X, Zhou X, Gu X, Wang S, Peng X, Yang G.
Abstract
The intestinal nematodeBaylisascarisschroederiis an important cause of death for wild and captive giant pandas.Inorganicpyrophosphatases (PPases) are critical for development and molting in nematode parasites and representpotentialtargets for vaccination. Here, anewPPase homologue, Bsc-PYP-1, from B.schroederiwas identified and characterized, and itspotentialas avaccinecandidatewas evaluated in a mouse challenge model. Sequence alignment of PPases from nematode parasites and other organisms show that Bsc-PYP-1 is a nematode-specific member of the family I soluble PPases. Immunohistochemistry revealed strong localization of native Bsc-PYP-1 to the body wall, gut epithelium, ovary and uterus of adult female worms. Additionally, Bsc-PYP-1 homologues were found in roundworms infecting humans (Ascaris lumbricoides), swine (Ascaris suum) and dogs (Toxocara canis). In twovaccinetrials,recombinantBsc-PYP-1 (rBsc-PYP-1) formulated with Freund complete adjuvant induced significantly highantigen-specific immunoglobulin (Ig)G but no IgE or IgM responses. Analysis of IgG-subclass profiles revealed a greater increase of IgG1 than IgG2a. Splenocytes from rBsc-PYP-1/FCA-immunizedmicesecreted low levels of T helper (Th)1-type cytokines, interferon-γ and interleukin (IL)-2, while producing significantly high levels of IL-10 and significantly elevated levels of IL-4 (Th2 cytokines) after stimulation with rBsc-PYP-1 in vitro. Finally, vaccinatedmicehad 69.02-71.15% reductions (in 2 experiments) in larval recovery 7 days post-challenge (dpc) and 80% survival at 80 dpc. These results suggest that Th2-mediated immunity elicited by rBsc-PYP-1 provides protectionagainstB.schroederi, and the findings should contribute to further development of Bsc-PYP-1 as acandidatevaccineagainstbaylisascariasis.
Copyright © 2013 Xie et al.; licensee BioMed Central Ltd.
Vet Res.2013 Oct 3;44:90. doi: 10.1186/1297-9716-44-90.
Read full text:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3851530/
