Lynch Garry W, Selleck Paul, Sullivan John S
J Mol Genet Med. 2009 Dec 15;3(2):205-9. doi: 10.4172/1747-0862.1000036.
Well understood are the adaptive and dramatic neutralizing homosubtypic antibody responses to hypervariable, immunodominant sites of the hemagglutinin (HA) and neuraminidase (NA) of individual influenza strains. These define influenza subtypes and vaccines modelled upon their HA and NA antigens provide seasonal neutralizing antibody protection against subsequent exposure to the strain and its close relatives, but give little if any protection against antigenically drifted or shifted strains. Contrasting to this is a different form of acquired antibody response, called heterosubtypic immunity. This provides a more seasoned adaptive antibody response to immune-recessive epitopes that are highly-conserved amongst strains. Although, such responses are of lower individual amplitudes than seasonal mechanisms they are active across influenza subtypes, and may give pre-emptive protection against new strains yet to emerge. Heterosubtypic immunities have been well studied in animals, but surprisingly there is minimal evidence for this type of antibody immunity in humans. Thus championed is the notion that seasoned humoral responses can through repeated exposure to sites widely conserved across different strains, cumulatively provide humans with a level of broad protection against emergent novel strains, such as H5N1, that is not afforded by seasonal humoral responses.
对于个体流感毒株血凝素（HA）和神经氨酸酶（NA）的高变、免疫显性位点的适应性和显著的中和同型抗体反应已得到充分理解。这些反应定义了流感亚型，基于其HA和NA抗原构建的疫苗可提供季节性中和抗体保护，以防止后续接触该毒株及其近亲毒株，但对抗原性漂移或转变的毒株几乎没有保护作用。与之形成对比的是另一种形式的获得性抗体反应，称为异型免疫。这种反应对毒株间高度保守的免疫隐性表位提供了更持久的适应性抗体反应。尽管这种反应的个体幅度低于季节性机制，但它们在流感亚型中都有活性，并且可能对尚未出现的新毒株提供先发制人的保护。异型免疫在动物中已得到充分研究，但令人惊讶的是，在人类中这种抗体免疫的证据极少。因此，有人提出这样一种观点，即通过反复接触不同毒株中广泛保守的位点，长期的体液反应可以累积地为人类提供一定程度的广泛保护，以抵御诸如H5N1等新出现的新型毒株，而季节性体液反应则无法提供这种保护。
