Cryptosporidium Parvum. Protective Immunity Against Cryptosporidiosis With Recombinant Lactobacillus Live Vaccines Expressing Cp966after Oral Immunization

Cryptosporidiosis is one of the most common infectious water-borne parasite diseases worldwide.The etiological agent is Cryptosporidium spp, a protozoan parasite of the Apicomplexa. Thediseases caused by these parasites cause significant production losses in the livestock sector.Cryptosporidium parvum is one of etiological agent transmitted with drinking and recreationalwater that contaminated followed the discovery of the environmentally robust oocyst stage.Cryptosporidiosis severity varies depending on host and parasite characteristics.Immunosupressed patients experience acute, chronic, or life-threatening diarrhea, and healthyindividuals experience self-limited and recurrent diarrhea. C. parvum oocysts can survive for longtime periods in the environment and are resistant to conventional water treatment disinfection, thischaracter impeded to control drinking and recreational water in cryptosporidiosis outbreak areas.Vaccines offer green solutions to control disease as they are sustainable, reducing reliance onpharmacological drugs. Lactococcus lactis, a LAB species, is a potential candidate for theproduction of biologically useful proteins and for plasmid DNA delivery to eukaryotic cells.A966-bp gene of C. parvum adhesion gene had been cloned into vector pW425et and transferredinto Lactobacillus plantarum by electroporation. And the immune influence of cp966recombinantlactobacillus was evaluated in mice and calves. The following results had been gained: There areconsistency of99.90%between cp966sequences and forecast the protein gene cgd4₄110inGenBank, and the consistency between proteins are100%. CP966protein was present on thesurface of C. parvum oocysts. The cp966becomes a candidate of vaccine. The recombinantlactobacillus vaccine was prepared with the extracellular region of cp966. Mice were immunedwith the recombinant Lactobacillus vaccine expressing cp966. The results implied that the cp966recombinant lactobacillus vaccine could up-regulate sIgA and the expression of TLR-4inintestinal tract. The Th2response was increased and IgG rose in sera. Imemune calves with therecombinant lactobacillus vaccine expressing cp966. The vaccine could up-regulate sIgA and IgG.Immuned calves were challenged with C. parvum oocysts, IL-2、IL-12、IFNγ and IL-4were rose.The mast cells in small intestinal mucosa were more than in control. The decreased worn rate ofthe experiment was67.14%. The results showed that the recombinant lactobacillus vaccineexpressing cp966had immuno-protective effect on C. parvum infectionIn conclusion, cp966could serve as the candidate gene of C. parvum immune protection vaccine.The recombinant cp966Lactobacillus vaccines played certain protective effects on calves, butfurther experiments should be carried out to determine the best immunization program.