Lai Lilin, Rouphael Nadine, Xu Yongxian, Sherman Amy C, Edupuganti Srilatha, Anderson Evan J, Lankford-Turner Pamela, Wang Dongli, Keitel Wendy, McNeal Monica M, Cross Kaitlyn, Hill Heather, Bellamy Abbie R, Mulligan Mark J
The Hope Clinic of the Emory Vaccine Center, Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, 500 Irvin Court, Decatur, GA 30030, USA.
Emory Children Center, Departments of Pediatrics and Medicine, Emory University School of Medicine, 2015 Uppergate Drive, Atlanta, GA 30322, USA.
Vaccines (Basel). 2020 Mar 13;8(1):126. doi: 10.3390/vaccines8010126.
The cellular immune responses elicited by an investigational vaccine against an emergent variant of influenza (H3N2v) are not fully understood. Twenty-five subjects, enrolled in an investigational influenza A/H3N2v vaccine study, who received two doses of vaccine 21 days apart, were included in a sub-study of cellular immune responses. H3N2v-specific plasmablasts were determined by ELISpot 8 days after each vaccine dose and H3N2v specific CD4+ T cells were quantified by intracellular cytokine and CD154 (CD40 ligand) staining before vaccination, 8 and 21 days after each vaccine dose. Results: 95% (19/20) and 96% (24/25) subjects had pre-existing H3N2v specific memory B, and T cell responses, respectively. Plasmablast responses at Day 8 after the first vaccine administration were detected against contemporary H3N2 strains and correlated with hemagglutination inhibition HAI (IgG: = 0.018; IgA: < 0.001) and Neut (IgG: = 0.038; IgA: = 0.021) titers and with memory B cell frequency at baseline (IgA: r = 0.76, < 0.001; IgG: r = 0.74, = 0.0001). The CD4+ T cells at Days 8 and 21 expanded after prime vaccination and this expansion correlated strongly with early post-vaccination HAI and Neut titers ( ≤ 0.002). In an adult population, the rapid serological response observed after initial H3N2v vaccination correlates with post-vaccination plasmablasts and CD4+ T cell responses.
一种针对流感（H3N2v）新出现变种的研究性疫苗所引发的细胞免疫反应尚未完全明确。在一项甲型H3N2v流感疫苗研究中，25名受试者接受了间隔21天的两剂疫苗接种，并被纳入细胞免疫反应的子研究。在每次接种疫苗后8天，通过酶联免疫斑点法（ELISpot）测定H3N2v特异性浆母细胞，在接种疫苗前、每次接种疫苗后8天和21天，通过细胞内细胞因子和CD154（CD40配体）染色对H3N2v特异性CD4+ T细胞进行定量分析。结果：分别有95%（19/20）和96%（24/25）的受试者预先存在H3N2v特异性记忆B细胞和T细胞反应。首次接种疫苗后第8天，针对当代H3N2毒株检测到浆母细胞反应，且与血凝抑制（HAI）（IgG：r = 0.018；IgA：r < 0.001）和中和（Neut）（IgG：r = 0.038；IgA：r = 0.021）滴度以及基线时的记忆B细胞频率相关（IgA：r = 0.76，p < 0.001；IgG：r = 0.74，p = 0.0001）。初次接种疫苗后第8天和第21天，CD4+ T细胞出现扩增，这种扩增与疫苗接种后早期的HAI和Neut滴度密切相关（p ≤ 0.002）。在成年人群中，初次接种H3N2v疫苗后观察到的快速血清学反应与接种疫苗后的浆母细胞和CD4+ T细胞反应相关。
