鳜浸泡嗜水气单胞菌全菌疫苗后皮肤黏液抗体的变化

应用间接ELISA方法,研究经嗜水气单胞菌(Aeromonas hydrophila)疫苗浸泡免疫后鳜(Siniperca chuatsi)皮肤黏液中抗体消长规律,以揭示鳜局部黏膜免疫在免疫保护中的作用及浸泡免疫的保护效果。结果表明,鳜皮肤黏液中抗体滴度在免疫后第7天达到峰值211,抗体从开始形成到消失持续21 d;添加佐剂(IMS1312、葡聚糖、莨菪碱、食盐)可以提高鳜皮肤黏液及血清中抗体滴度和相对免疫保护率,其中添加IMS1312组免疫保护率最高,达77.8%,免疫保护与抗体滴度成正相关(R2=0.79,P<0.05);以溶菌酶为代表的非特异性免疫在免疫后1周内即抗体未形成时,对鱼体起主要保护作用。此外,通过比较鳜血清与皮肤黏液中的抗体消长规律,发现血清中抗体滴度峰值出现时间较迟(第14天),抗体持续时间较长(42 d),初步推断鳜皮肤黏膜中可能存在相对独立于全身免疫系统的局部黏膜免疫系统。

Changes of skin mucus antibody in mandarinfish (Siniperca chuatsi) after immersion vaccination against Aeromonas hydrophila

As a comercially important fish species,mandarinfish,Siniperca chuatsi,has been cultured extensively,whereas recently,many kinds of diseases caused by high density and deformed management has broken out frequently.Immersion immunity,as an efficient and convenient method to prevent diseases,has attracted more and more attentions.By way of this administration,the antigen enters into fish body mainly through its gill and skin.So to study the local mucus immunity is important.With the method of indirect enzyme-linked immunosorbent assay (ELISA),kinetics of antibody production in skin mucus of Siniperca chuatsi,after immersion with inactivated Aeromonas hydrophila,was studied to determine the function of mucus immunity in immunoprotection.The results showed that the peak of antibody titer(211) in mucus presented on the 7th day and lasted about 21d from the beginning.Interestingly,mucosal antibody titer in all of these experimental groups peaked prior to serum antibody,suggesting stimulation of mucus defenses occured earlier.Moreover,both mucosal and serum antibody titers as well as RPS were elevated by adding adjuvant.Among the six groups,the one with IMS1312 adjuvant reached the highest RPS value of 77.8%.We also found that the RPS of immunized mandarinfish was positively correlated with antibody titers.Non-specific immunity represented by the content of lysozyme played a major role in protection within the first week after vaccination.Additionally,compared with antibody production in serum(e.g.,peaked on the 14th day and lasted about 42d),we speculated that local mucus immunity system might exist independently.