Development of mucosal vaccines for prevention of prevention of respiratory infectious diseases

重组霍乱毒素B亚单位（rCTB）是由携带pNU212-CTB的短芽胞杆菌产生的，可作为粘膜佐剂，当每种疫苗与rCTB在小鼠鼻内共给药时，可诱导持续保护水平的白喉和破伤风毒素中和抗体和高水平的抗乙型肝炎疫苗血清IgG抗体。在此基础上，研究了rCTB对肺炎链球菌流感血凝素（HA）疫苗和荚膜多糖（PS）疫苗的佐剂性。用流感病毒A/New Caledonia (NC)/20/99 （H1N1）和B/Johannesburg (JB)/5/99制备[1]HA疫苗，在rCTB存在和不存在的情况下，分别用每种疫苗1μg鼻内免疫小鼠，第0、14.21和28天，第35天处死。rCTB的存在显示A/NCHA疫苗和B/JB HA疫苗特异性血清ELISA IgG抗体滴度和血凝抑制（HI）抗体滴度以及肺和鼻腔粘膜IgA抗体反应显著升高。[2]经A/NCHA疫苗（含和不含rCTB）鼻内免疫的小鼠鼻内感染小鼠适应型流感病毒A/爱知/88/02 （H1N1）。所有接受HA和rCTB的小鼠都完全免受感染，但单独接受HA的8只小鼠中有3只在4天内死亡，所有未免疫的小鼠在6天内死亡。在上述条件下，分别用含和不含rCTB的rCTB结合PS疫苗鼻内免疫小鼠。血清PS特异性IgG、IgA和IgM抗体滴度与rCTB无关，肺粘膜PS特异性IgA抗体滴度在rCTB存在时显著升高，提示可能存在rcttb结合的PS疫苗。

Recombinant cholera toxin B subunit (rCTB) which is produced by Bacillus brevis carrying pNU212-CTB acts as a mucosal adjuvant and induces constantly protective levels of diphtheria and tetanus toxin-neutralizing antibodies and high levels of anti-hepatitis B vaccine serum IgG antibodies when each vaccine is intranasally co-administered with rCTB in mice. On the basis of these results adjuvanticity of rCTB was investigated on influenza hemagglutinin (HA) vaccine and capsular polysaccharide (PS) vaccine of Sreptococus pneumoniae. [1]HA vaccines were prepared from influenza viruses A/New Caledonia (NC)/20/99 (H1N1) and B/Johannesburg (JB)/5/99, and mice were intranasally immunized with 1μg of each HA vaccine in the presence and absence of rCTB on days 0, 14.21 and 28, and sacrificed on day 35. The presence of rCTB showed significantly high levels of A/NCHA vaccine-and B/JB HA vaccine-specific serum ELISA IgG antibody titers and hemagglutination inhibition (HI) antibody titers and mucosal IgA antibody responses in the lungs and the nasal cavities. [2]Mice immunized intranasally with A/NCHA vaccine with and without rCTB were intranasally infected with mouse-adapted influenza virus A/Aichi/88/02 (H1N1). All mice receiving HA with rCTB were completely protected from infection, but 3 of 8 mice receiving HA alone died within 4 days and all nonimmunized mice died within 6 days. [3]Mice were intranasally immunized with rCTB-conjugated PS vaccine with and without rCTB based on the above conditions. Serum PS-specific IgG, IgA and IgM antibody titers elevated irrespective of rCTB and mucosal PS-specific IgA antibody titers in the lungs werre significantly high in the presence of rCTB, suggesting the possibility of rCTB-conjugated PS vaccine.