Promotion of the immunity of piglets to Hog cholera vaccine induced by shuffled pig interleukin-2 gene and CpG immunostimulatory sequences encapsulated in chitosan nanoparticles

Cloning and Expression of the Tibetan Pig Interleukin-23 Gene and Its Promotion of Immunity of Pigs to PCV2 Vaccine

Vaccines against Porcine circovirus type 2 (PCV2) have been studied intensely and found to be effective in decreasing mortality and improving growth in swine populations. In this study, interleukin-23 (IL-23) gene was cloned from peripheral blood mononuclear cells (PBMCs) of Tibetan pigs and inserted into a eukaryotic VR1020 expression vector-VRIL23. Coated with chitosan (CS), the VRIL23-CS was intramuscularly injected into 3-week-old piglets with PCV2 vaccine. The blood was collected after vaccination at 0, 1, 2, 4, 8, and 12 weeks, respectively, to detect the immunological changes. The IgG2a and specific PCV2 antibodies were detected using ELISA, and blood CD4+ and CD8+ T cells were quantified by flow cytometry. Quantitative fluorescence PCR was used to evaluate the expression of immune genes. The results indicate that leukocytes, erythrocytes, and CD4+ and CD8+ T cells increased significantly in the blood of VRIL23-CS inoculated piglets in comparison with the control (p < 0.05) and so did the IgG2a and PCV2 antibodies. In addition, the expressions of Toll-like receptor (TLR) 2, TLR7, cluster of differentiation (CD) 45, IL-15, IL-12, signal transducer and activator of transcription (STAT)1, STAT2, STAT3, STAT4, and B-cell lymphoma (Bcl)-2 genes were also obviously higher in the VRIL23-CS inoculated pigs at different time points (p < 0.05). Overall, the results demonstrated that VRIL23-CS can enhance the comprehensive immune responses to PCV2 vaccine in vivo and has the promising potential to be developed into a safe and effective adjuvant to promote the immunity of pig against PCV disease.

Immunomodulatory and antioxidant effects of pomegranate peel polysaccharides on immunosuppressed mice

This work aims to analyze the immunomodulatory effect of pomegranate peel polysaccharides (PPP) on the immunosuppressed mice induced by cyclophosphamide (CTX). All the mice were divided into 6 groups randomly and the immunoprophylaxis mice were administrated with PPP [100, 200, 400 mg/(kg·d)] by gavage for consecutive 28 days. The results showed that PPP can slow down the decline of body weight and increase the immune organ index of the immunosuppressed mice. Compared to the model mice, the enzymatic activity of LDH (lactate dehydrogenase) and ACP (acid phosphatase) of the mice spleen administrated with PPP by gavage was enhanced significantly. PPP stimulated proliferation and secretion of splenic lymphocytes and markedly increased the immunoglobulin (Ig-A, Ig-G and Ig-M) expression and the release of cytokines (TNF-α, IL-2 and INF-γ) in cyclophosphamide-induced immunosuppressed mice. Hepatic antioxidant enzymatic activities of T-AOC (total antioxidant capacity), T-SOD (total superoxide dismutase), GSH-PX (glutathione peroxidase) and CAT (catalase) were markedly increased when the mice were administrated with high dosage of PPP. So it can be concluded that PPP could be used as an efficacious adjacent immunopotentiating therapy or an alternative means in lessening chemotherapy-induced immunosuppression, and also can be utilized as immunostimulants for food and pharmaceutical industries.

Co-expression of mFat-1 and pig IGF-1 genes by recombinant plasmids in modified chitosan nanoparticles and its synergistic effect on mouse immunity

To develop a cost-effective molecular regulator to improve growth metabolism and immunity of animals, a recombinant plasmid co-expressing fatty acid desaturase (mFat-1) and pig insulin growth like factor 1 (IGF-1) genes was constructed by the 2 A self-cleavage technique. After entrapment within modified chitosan nanoparticles (chitosan modified with polyethyleneglycol–polyethylenimine, CPP), the recombinant plasmid was injected intramuscularly into mice. Compared with controls, co-expression of mFat-1 and IGF-1 significantly raised the level of serum IGF-1, and increased the liver and muscle docosa hexaenoic acid (DHA) content. Th and Tc cell levels were also elevated, as were expression levels of serum IL-4 and IL-6 genes. These results demonstrate that the immunity and metabolism of an animal can be effectively improved by co-expression of mFat-1 and IGF-1 genes in vivo, which may contribute to further development of novel immunomodulators with beneficial effects on growth metabolism and immunity.

Rabbit nasal immunization against influenza by dry-powder form of chitosan nanospheres encapsulated with influenza whole virus and adjuvants

Influenza virus is one of the main causes of respiratory diseases in human. Although different vaccines have been produced during past decades, there is still a huge demand for a safe influenza vaccine with the ability to induce mucosal immune responses and sufficient protection, especially in elderly patients. In this study, chitosan nanospheres were employed as the drug delivery system. Influenza virus, CpG oligodeoxynucleotide (CpG ODN) and Quillaja saponins (QS) were incorporated in this nanospheric system. Three doses of dry powder nanosphere vaccine were nasally administered to rabbits on days 0, 45 and 60, followed by a final booster injection on day 75. Both humoral and cellular immune responses were investigated. Hemagglutination inhibition (HI) antibody titer was elevated in all groups compared to the control group at the end of vaccination in rabbits receiving nanospheres loaded with virus and CpG, CH(WV+CpG) (P<0.001). Rabbit serum IgG raised significantly in all the vaccinated groups, with the highest responses in CH(WV+CpG) group. CH(WV+CpG) and CH(WV) induced significant sIgA titers (P<0.001). CpG adjuvant also showed a prominent role in the stimulation and secretion of of IL-2 and IFN-γ cytokines (3 and 3.5 fold increase, respectively). Finally, as CH(WV+CpG) depicted to be effective in induction of humoral and cellular immune responses after nasal administration, this nanoparticulate adjuvant could be identified as an efficient adjuvant/delivery system for mucosal immunization against influenza virus.