Double-stranded Phosphodiester Cytosine-guanine Oligodeoxynucleotide Complexed with Calcium Phosphate As a Potent Vaccine Adjuvant for Activating Cellular and Th1-type Humoral Immunities
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Conventional class B cytosine-guanine (CpG) (CpG-B) oligodeoxynucleotide (ODNs) consisting of a single-stranded (ss) phosphorothioate (PT) backbone (ss CpG-B-PT) is converted from a proinflammatory cytokine inducer to a type-I interferon (IFN) inducer when complexed with cationic materials. In this study, we designed ss CpG-B and double-stranded (ds) CpG-B ODNs with a phosphodiester (PD) backbone (ss CpG-B-PD and ds CpG-B-PD, respectively) that became type-I IFN inducers upon complexation with Lipofectamine 2000 (Lipo), a cationic liposome. The ds CpG-B-PD complex induced higher IFN-β expression in mouse macrophage-like RAW264 cells than ss CpG-B-PD and ss CpG-B-PT complexes. The fold induction of IFN-β increased with the number of CpG motifs in ds CpG-B-PD, and a complex of ds CpG-B-PD consisting of 72 base pairs with nine CpG motifs (ds CpG-B72-PD) and Lipo showed the highest capacity to induce IFN-β. The materials and method used for complexation influenced the degree of IFN-β induction: ds CpG-B72-PD entrapped by calcium phosphate (CaP) (ds CpG-B72-PD/CaP) showed a higher induction capacity than ds CpG-B72-PD adsorbed onto the CaP surface. Entrapment of ds CpG-B72-PD by CaP also enhanced the induction of the proinflammatory cytokine interleukin-12. Vaccinating mice with ds CpG-B72-PD/CaP in conjunction with ovalbumin (OVA) increased the ratios of OVA-specific CD8 T cells to total CD8 T cells in peripheral blood and of OVA-specific IgG2a associated with helper T (Th)1 cells to OVA-specific IgG1 associated with Th2 cells. These results indicate that ds CpG-B72-PD/CaP is an effective vaccine adjuvant that can activate both cellular and Th1-type humoral immune responses.
Zhao D, Tu A, Shobo M, Le N, Yoshikawa C, Sugai K Biomolecules. 2022; 12(12).
PMID: 36551297 PMC: 9775190. DOI: 10.3390/biom12121868.
Song X, Li H, Zhang L, Zhang X, Zhao L, Zhang G Vet Sci. 2022; 9(7).
PMID: 35878372 PMC: 9316975. DOI: 10.3390/vetsci9070355.
Safitri F, Tu A, Hoshi K, Shobo M, Zhao D, Witarto A Biomolecules. 2021; 11(11).
PMID: 34827615 PMC: 8615816. DOI: 10.3390/biom11111617.
Design and application of nanoparticles as vaccine adjuvants against human corona virus infection.
Mao L, Chen Z, Wang Y, Chen C J Inorg Biochem. 2021; 219:111454.
PMID: 33878530 PMC: 8007196. DOI: 10.1016/j.jinorgbio.2021.111454.