在我们已建立的柯萨奇病毒B3型（CVB3）黏膜疫苗chitosan-pVP1基础上，引入C家族趋化因子淋巴细胞趋化因子（LTN），以期诱导更强的粘膜免疫应答，获得更为有效的免疫保护作用。将pLTN与pVP1各50 μg混合后再与chitosan形成共聚复合物, 隔周滴鼻免疫小鼠，共4次，末次免疫后2周检测血清IgG、粪便IgA及肠系膜淋巴结细胞毒T淋巴细胞（CTL）活性。同时，以3LD50s CVB3腹腔感染小鼠，7天后检测血清肌酸激酶（CK）活性及心肌病理学改变。结果显示，与对照组相比，chi-(pVP1+pLTN)可显著增强CVB3特异性血清IgG，粪便IgA以及肠系膜淋巴结特异性CTL应答。病毒攻击后，该组心肌炎发病率仅为16.7%, 显著低于chi-(pVP1+pcDNA3.1)组的33.3%。心肌组织病理显示，chi-(pVP1+pLTN)组心外膜下仅有轻微炎症，而chi-(pVP1+pcDNA3.1)组除心外膜下有较多淋巴细胞聚集外，心肌内尚有少量炎症浸润和坏死灶，提示LTN与VP1质粒经chitosan共包装后进行滴鼻免疫，可增强CVB3特异性粘膜免疫应答，更有效地预防病毒性心肌炎的发生。

To improve the mucosal immune responses and protection against coxsackievirus B3 (CVB3), on the basis of our previously prepared chitosan-pVP1 mucosal vaccine, plasmid encoding lymphotactin (LTN), a C family chemokine, was introduced. chi-(pVP1+pLTN) were prepared by conjugating chitosan with the mixture of 50 μg pVP1 and pLTN. Male BALB/c mice were immunized 4 times biweekly. Two weeks after the final immunization, the level of CVB3-specific serum IgG, fecal IgA and mucosal CTL activity were quantified. Meanwhile, mice were challenged with 3 LD50s, serum creatine kinase (CK) activity and histopathological changes in heart tissue were measured. Compared with control groups, immunization with chi-(pVP1+pLTN) significantly increased the levels of CVB3-specific serum IgG and fecal IgA, and enhanced the mucosal CTL activity. The incidence of myocarditis in mice receiving chi-(pVP1+pLTN) was 16.7%, significantly lower than 33.3% in mice receiving chi-(pVP1+pcDNA3.1). Histopathological analysis showed that fewer inflammatory cells under the epicardium in the hearts of co-immunized mice compared with that of control groups. In conclusion, intranasal co-administration of LTN plasmid via chitosan nanoparticle could enhance CVB3 specific mucosal immune responses and provide more efficient protection against CVB3-induced myocarditis.