A Combination of Flt3 Ligand cDNA and CpG Oligodeoxynucleotide as Nasal Adjuvant Elicits Protective Secretory-IgA Immunity to Streptococcus pneumoniae in Aged Mice

作者：Fukuyama Yoshiko; King Janice D; Kataoka Kosuke; Kobayashi Ryoki; Gilbert Rebekah S; Hollingshead Susan K; Briles David E; Fujihashi Kohtaro^*

来源：The Journal of Immunology, 2011, 186(4): 2454-2461.

DOI：10.4049/jimmunol.1002837

Our previous study showed that a combination of a plasmid-expressing Flt3 ligand (pFL) and CpG oligodeoxynucleotides (CpG ODN) as a combined nasal adjuvant elicited mucosal immune responses in aged (2-y-old) mice. In this study, we investigated whether a combination of pFL and CpG ODN as a nasal adjuvant for a pneumococcal surface protein A (PspA) would enhance PspA-specific secretory-IgA Ab responses, which could provide protective mucosal immunity against Streptococcus pneumoniae infection in aged mice. Nasal immunization with PspA plus a combination of pFL and CpG ODN elicited elevated levels of PspA-specific secretory-IgA Ab responses in external secretions and plasma in both young adult and aged mice. Significant levels of PspA-specific CD4(+) T cell proliferative and PspA-induced Th1- and Th2-type cytokine responses were noted in nasopharyngeal-associated lymphoreticular tissue, cervical lymph nodes, and spleen of aged mice, which were equivalent to those in young adult mice. Additionally, increased numbers of mature-type CD8, CD11b-expressing dendritic cells were detected in mucosal inductive and effector lymphoid tissues of aged mice. Importantly, aged mice given PspA plus a combination of pFL and CpG ODN showed protective immunity against nasal S. pneumoniae colonization. These results demonstrate that nasal delivery of a combined DNA adjuvant offers an attractive possibility for protection against S. pneumoniae in the elderly. The Journal of Immunology, 2011, 186: 2454-2461.

• 出版日期2011-2-15