title: Immunization of aged pigs with attenuated pseudorabies virus vaccine combined with CpG oligodeoxynucleotide restores defective Th1 immune responses.
abstract: OBJECTIVE
  Attempts to immunize aged subjects often result in the failure to elicit a protective immune response. Murine model studies have shown that oligonucleotides containing CpG motifs (CpG ODN) can stimulate immune system in aged mice as effectively as in young mice. Since many physiological and pathophysiological data of pigs can be transferred to humans, research in pigs is important to confirm murine data. Here we investigated whether immunization of aged pig model with attenuated pseudorabies virus vaccine (PRV vaccine) formulated with CpG ODN could promote a successful development of immune responses that were comparable to those induced in young pigs in a similar manner.
  
  
  METHODS
  Young and aged pigs were immunized IM with PRV vaccine alone, or in combination with CpG ODN respectively. At days 3, 7, 14 post immunization sera were assayed by ELISA for IgG titres, at day 7 for IgG1 and IgG2 subtypes titres. All blood samples collected in evacuated test tubes with K-EDTA at day 7 were analyzed for flow cytometer assay. Blood samples at day 7 collected in evacuated test tubes with heparin were analysed for antigen-specific cytokines production and peripheral blood mononuclear cells (PBMCs) proliferative responses.
  
  
  RESULTS
  CpG ODN could enhance Th1 responses (PRV-specific IgG2/IgG1 ratio, proliferative responses, Th1 cytokines production) when used as an adjuvant for the vaccination of aged pigs, which were correlated with enhanced CD4+ T cells percentage, decreased CD4+CD8+CD45RO+ T cells percentage and improved PRV-specific CD4+ T cells activation.
  
  
  CONCLUSIONS
  Our results demonstrate a utility for CpG ODN, as a safe vaccine adjuvant for promoting effective systemic immune responses in aged pig model. This agent could have important clinical uses in overcoming some of age-associated depressions in immune function that occur in response to vaccination.
authors.affiliation: College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, China.
authors.forename: Feiping
authors.initials: F
authors.lastname: Ming
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Pinpin
authors.initials: P
authors.lastname: Chu
authors.forename: Miaopeng
authors.initials: M
authors.lastname: Ma
authors.forename: Juqing
authors.initials: J
authors.lastname: Shi
authors.forename: Haiming
authors.initials: H
authors.lastname: Cai
authors.forename: Chaoyuan
authors.initials: C
authors.lastname: Huang
authors.forename: Huazhou
authors.initials: H
authors.lastname: Li
authors.forename: Zhenggu
authors.initials: Z
authors.lastname: Jiang
authors.forename: Houguang
authors.initials: H
authors.lastname: Wang
authors.forename: Weifang
authors.initials: W
authors.lastname: Wang
authors.forename: Shuiqing
authors.initials: S
authors.lastname: Zhang
authors.forename: Linghua
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000276:Adjuvants, Immunologic; D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D011558:Herpesvirus 1, Suid / Q000276:immunology*; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016130:Immunophenotyping; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000276:immunology*; D010641:Phenotype; D011557:Pseudorabies / Q000276:immunology / Q000517:prevention & control*; D022421:Pseudorabies Vaccines / Q000008:administration & dosage / Q000276:immunology*; D013552:Swine; D018417:Th1 Cells / Q000276:immunology*; D014613:Vaccines, Attenuated
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; C408982:CPG-oligonucleotide; D016207:Cytokines; D007074:Immunoglobulin G; D009838:Oligodeoxyribonucleotides; D022421:Pseudorabies Vaccines; D014613:Vaccines, Attenuated