Tamura S, Funato H, Nagamine T, Aizawa C, Kurata T
Department of Pathology, National Institute of Health, Tokyo, Japan.
Vaccine. 1989 Dec;7(6):503-5. doi: 10.1016/0264-410x(89)90273-9.
In a previous paper, it was shown that cholera toxin B subunit (CTB) augments the production of protective antibodies to influenza virus when CTB is inoculated intranasally into Balb/c mice together with influenza HA vaccine. The present study was designed to determine whether the effectiveness of CTB as a potent adjuvant for nasal vaccination could be limited by pre-existing immunity to CTB. Mice were sensitized by intranasal inoculation of either 1 or 0.05 microgram of CTB 2, 4 and/or 6 weeks before nasal vaccination. They were then vaccinated by either a single inoculation of vaccine together with 1 microgram of CTB or a two-dose regimen, composed of a primary inoculation of vaccine together with 0.05 microgram of CTB and a subsequent inoculation of vaccine alone. Levels of nasal IgA antibodies to CTB increased with the increase of the dose of CTB and the frequency of CTB-inoculation. Pre-existing immunity to CTB, however, did not significantly reduce the levels of both nasal IgA and serum haemagglutination-inhibiting (HI) antibodies to influenza virus and did not change the ability of the vaccinated mice to resist viral challenge. These results suggest that a relatively low dose of CTB could be inoculated repeatedly into animals as an adjuvant for nasal vaccination.
在之前的一篇论文中，研究表明，当霍乱毒素B亚基（CTB）与流感HA疫苗一起经鼻接种到Balb/c小鼠体内时，它能增强针对流感病毒的保护性抗体的产生。本研究旨在确定CTB作为鼻内疫苗接种的有效佐剂的效果是否会受到对CTB的预先存在的免疫力的限制。在鼻内接种疫苗前2、4和/或6周，通过鼻内接种1微克或0.05微克CTB使小鼠致敏。然后，它们通过单次接种疫苗加1微克CTB或两剂方案进行接种，两剂方案包括初次接种疫苗加0.05微克CTB，随后单独接种疫苗。针对CTB的鼻内IgA抗体水平随着CTB剂量和CTB接种频率的增加而升高。然而，对CTB的预先存在的免疫力并没有显著降低针对流感病毒的鼻内IgA和血清血凝抑制（HI）抗体水平，也没有改变接种疫苗的小鼠抵抗病毒攻击的能力。这些结果表明，相对低剂量的CTB可以作为鼻内疫苗接种的佐剂反复接种到动物体内。
