H9N2亚型禽流感病毒不同流行株抗原性和免疫原性的比较研究

摘要

为研究H9N2亚型禽流感病毒(AIV)的变异情况,采用交叉HI试验、细胞中和试验和攻毒保护试验对1998-2008年间分离到的25株H9N2 AIV的抗原性和免疫原性进行了研究.结果显示,依据不同毒株与Hp株免疫产生HI抗体的结果可将25个毒株分为3类,第1类HI效价4.0log2～5.0log2的为12#、17#、18#；第2类毒株HI效价6.0log2～7.0log2的为2#、21#、5#、22#、11#、25#、15#、16#；其余毒株的HI效价为7.0log2～8.0log2.这证实不同H9N2 AIV流行毒株间的抗原性有差异.选取代表性的8株H9N2 AIV毒株进行中和试验,结果显示其抗原相关性在0.42～0.84.除了3#与14#、11#与17#的抗原性有明显差异外(相关性R值分别为0.46、0.42),其余毒株间的抗原性无明显差异或仅有较小的差异.抗原性不同的H9N2 AIV株对Hp株免疫鸡的攻毒保护试验显示Hp株能够对抗原性有差异的攻毒株(10#、12#、17#)产生有效保护(9/10),联合攻毒试验结果显示Hp毒株免疫鸡可抗其他毒株(9#+15#和16#+17#)的联合攻击,保护率9/10以上.以上结果显示,H9N2 AIV Hp株与多数流行毒株间在免疫原性上无明显差异,H9N2 AIV多数流行毒株间的免疫原性没有发生根本改变.%Antigenicity and immunogenicity of 25 H9N2 subtype avian influenza viruses isolated from China during 1998-2008 were compared and analyzed by crossing-hemagglutinin inhibition test(HI) , cells neutralization test and challenging test. HI test results revealed that the 25 H9N2 AIVs were divided into three classes, the first class including 12 # , 17 # , 18 # , whose HI titer was from 4. 0 log2 to 5. 0 log2, the second including 2 # , 5 # , 11 # , 15 # , 16 # , 21 # , 22 # and 25 # , whose titer was from 6. 0 log2 to 7. 0 log2, the rest strains formed the third whose titer was from 7. 0 log2 to 8. 0 log2. It was indicated that the antigenicity of different isolation strains of H9N2 AIV displayed variant, and Maximum difference of them in HI titer reached to 3. 15 log2. Neutralization test demonstrated that the antigen correlation (R) among 8 representative H9N2 AIV strains selected were from 0. 42 to 0. 84, the antigenicity between 3 # and 14 # , 11 # and 17 # showed diversity (the R was 0. 46 and 0. 42) , but that of all the rest strains showed inconspicuous difference. Cross challenging protection test among 6 representative H9N2 AIV strains selected made clear that the antibody induced by the vaccine from the viruses could protect the chicken against infection. The birds vaccinated with Hp vaccine could be protected against the challenge from both three H9N2 AIV strains (10# , 12 # , 17 # ) displaying different antigenici-ty, and joint-challenge with different viruses (9 # andl5 # ,16 # and 17 # ). It was suggested that the radical change in immunogenicity of the prevalent H9N2 AIVs did not happen up to now.