CpG ODN Enhances Immunization Effects of Hepatitis B Vaccine in Aged Mice

Oligodeoxynucleotides(ODN)containing unmethylated CpG dinucleotides in contexts of unique sequence (CpG motifs)is active as adjuvant in induction of cellular and humoral immune responses in young mice.To date,there are only limited reports about effect of CpG ODN on immune responses against hepatitis B(HB) infection in aged mice.Our studies demonstrated there were significant increases in secreting of total anti-HB IgG,IgG1 and IgG2a,as well as of IL-12 and IFN-γ,when CpG ODNs were injected together with hepatitis B antigen in aged mice.Moreover,CpG ODN could stimulate proliferation of spleen lymphocytes in a dose-dependent manner.Taken together,the results we obtained indicate that the adding of CpG ODN into the vaccine antigen might be useful in development of more effective vaccination for inducing anti-HB virus responses in the elderly.Cellular & Molecular Immunology.2004;1(2):148-152.

LNP-CpG ODN-adjuvanted varicella-zoster virus glycoprotein E induced comparable levels of immunity with Shingrix^(TM) in VZV-primed mice

Latent varicella-zoster virus(VZV)may be reactivated to cause herpes zoster,which affects one in three people during their lifetime.The currently available subunit vaccine Shingrix^(TM) is superior to the attenuated vaccine Zostavax®in terms of both safety and efficacy,but the supply of its key adjuvant component QS21 is limited.With ionizable lipid nanoparticles(LNPs)that were recently approved by the FDA for COVID-19 mRNA vaccines as carriers,and oligodeoxynucleotides containing CpG motifs(CpG ODNs)approved by the FDA for a subunit hepatitis B vaccine as immunostimulators,we developed a LNP vaccine encapsulating VZV-glycoprotein E(gE)and CpG ODN,and compared its immunogenicity with Shingrix^(TM) in C57BL/6J mice.The results showed that the LNP vaccine induced comparable levels of gE-specific IgG antibodies to Shingrix^(TM) as determined by enzymelinked immunosorbent assay(ELISA).Most importantly,the LNP vaccine induced comparable levels of cellmediated immunity(CMI)that plays decisive roles in the efficacy of zoster vaccines to Shingrix^(TM) in a VZVprimed mouse model that was adopted for preclinical studies of Shingrix^(TM) .Number of IL-2 and IFN-γsecreting splenocytes and proportion of T helper 1(Th1)cytokine-expressing CD4^(+)T cells in LNP-CpG-adjuvanted VZV-gE vaccinated mice were similar to that of Shingrix^(TM) boosted mice.All of the components in this LNP vaccine can be artificially and economically synthesized in large quantities,indicating the potential of LNP-CpGadjuvanted VZV-gE as a more cost-effective zoster vaccine.