title: Porcine interleukin-2 gene encapsulated in chitosan nanoparticles enhances immune response of mice to piglet paratyphoid vaccine.
abstract: Interleukin-2 (IL-2) is vital to elicit and amplify the cellular and humoral immune responses to foreign antigens, which is extensively utilized in the control of infectious disease and treatment of various cancers. Porcine and murine IL-2 genes were, respectively, subcloned into VR1020, designated as VPIL-2 and VMIL-2, and then encapsulated in chitosan nanoparticles (CNP) prepared by ionic linkage. The BALB/c mice were intramuscularly co-administrated with chitosan-IL-2 nanoparticles (CNP-IL2) and paratyphoid vaccine to test the adjuvant effect of CNP-IL2. On day 35, the immunized mice were orally challenged with virulent Salmonella. The content of IgG, IgA, IgM, IL-2, IL-4, IL-6 and specific antibody titer as well as the number of immunocompetent cells were systematically analyzed in the vaccinated mice. The results revealed that the levels of immunoglobulins, cytokines, the specific antibodies, together with the numbers of lymphocytes significantly increased in vaccinated mice inoculated with CNP-VPIL2 in contrast with those with naked IL-2 plasmids and blank plasmids. The CNP-VPIL2 immunized mice exhibited higher humoral and cellular immune responses, less severe clinical signs and lesions of disease caused by the bacteria than the other groups after challenge. These findings suggest that CNP-VPIL2 has a significant enhancement effect on immune responses of mice, which results in better immunoprotection against Salmonella infection, indicating that CNP-VPIL2 could be employed as an effective immunoadjuvant to elevate immunity of animals to conventional vaccines.
authors.affiliation: Key Lab for Bio-Resource and Eco-Environment of Education Ministry, Bioengineering Research Center for Animal Disease Prevention and Control, Life Science College, Sichuan University, Wangjiang Road No. 29, Chengdu 610064, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Jianlin
authors.initials: J
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Yingyi
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhao
authors.initials: Z
authors.lastname: Xie
authors.forename: Mei
authors.initials: M
authors.lastname: Wu
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Zhongzhong
authors.initials: Z
authors.lastname: Zhao
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.forename: Manliang
authors.initials: M
authors.lastname: Fu
authors.forename: Kaiyuan
authors.initials: K
authors.lastname: Wu
authors.forename: Cheng
authors.initials: C
authors.lastname: Chi
authors.forename: Hongning
authors.initials: H
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Gao
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D048271:Chitosan; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D007136:Immunoglobulins / Q000096:biosynthesis*; D007273:Injections, Intramuscular; D007376:Interleukin-2 / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles; D011897:Random Allocation; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000517:prevention & control; D013552:Swine; D014436:Typhoid-Paratyphoid Vaccines / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D016207:Cytokines; D007136:Immunoglobulins; D007376:Interleukin-2; D014436:Typhoid-Paratyphoid Vaccines; D048271:Chitosan