Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, P.R. China.
Department of Clinical Laboratory, The First People's Hospital of Wuhu, Wuhu, Anhui, P.R. China.
BMC Infect Dis. 2024 Apr 2;24(1):371. doi: 10.1186/s12879-024-09262-8.
There is an urgent clinical need for developing novel immunoprophylaxis and immunotherapy strategies against Staphylococcus aureus (S. aureus). In our previous work, immunization with a tetra-branched multiple antigenic peptide, named MAP2-3 that mimics lipoteichoic acid, a cell wall component of S. aureus, successfully induced a humoral immune response and protected BALB/c mice against S. aureus systemic infection. In this study, we further investigated whether vaccination with MAP2-3 can elicit immunologic memory.
BALB/c mice were immunized with MAP2-3 five times. After one month of the last vaccination, mice were challenged with heat-killed S. aureus via intraperitoneal injection. After a 7-day inoculation, the percentage of plasma cells, memory B cells, effector memory T cells, and follicular helper T cells were detected by flow cytometry. The levels of IL-6, IL-21, IL-2, and IFN-γ were measured by real-time PCR and ELISA. Flow cytometry results were compared by using one-way ANOVA or Mann-Whitney test, real-time PCR results were compared by using one-way ANOVA, and ELISA results were compared by using one-way ANOVA or student's t-test.
The percentage of plasma cells and memory B cells in the spleen and bone marrow from the MAP2-3 immunized mice was significantly higher than that from the control mice. The percentage of effector memory T cells in spleens and lymphoid nodes as well as follicular helper T cells in spleens from the MAP2-3 immunized mice were also higher. Moreover, the levels of IL-6 and IL-21, two critical cytokines for the development of memory B cells, were significantly higher in the isolated splenocytes from immunized mice after lipoteichoic acid stimulation.
Immunization with MAP2-3 can efficiently induce memory B cells and memory T cells.
目前迫切需要开发针对金黄色葡萄球菌（S. aureus）的新型免疫预防和免疫治疗策略。在我们之前的工作中，用一种名为 MAP2-3 的四分支多抗原肽免疫接种，该肽模拟金黄色葡萄球菌细胞壁成分脂磷壁酸，成功诱导了体液免疫反应，并保护 BALB/c 小鼠免受金黄色葡萄球菌全身感染。在这项研究中，我们进一步研究了 MAP2-3 疫苗接种是否可以引发免疫记忆。
用 MAP2-3 对 BALB/c 小鼠进行 5 次免疫接种。最后一次接种一个月后，通过腹腔注射用热失活的金黄色葡萄球菌对小鼠进行攻毒。接种 7 天后，通过流式细胞术检测浆细胞、记忆 B 细胞、效应记忆 T 细胞和滤泡辅助 T 细胞的百分比。通过实时 PCR 和 ELISA 测量白细胞介素 6 (IL-6)、白细胞介素 21 (IL-21)、白细胞介素 2 (IL-2)和干扰素 γ (IFN-γ)的水平。通过单向方差分析或曼-惠特尼检验比较流式细胞术结果，通过单向方差分析比较实时 PCR 结果，通过单向方差分析或学生 t 检验比较 ELISA 结果。
MAP2-3 免疫小鼠的脾和骨髓中浆细胞和记忆 B 细胞的百分比明显高于对照组。MAP2-3 免疫小鼠的脾和淋巴结中的效应记忆 T 细胞以及脾中的滤泡辅助 T 细胞的百分比也更高。此外，在脂磷壁酸刺激后从免疫小鼠分离的脾细胞中，两种关键的记忆 B 细胞发育细胞因子白细胞介素 6 (IL-6)和白细胞介素 21 (IL-21)的水平显著升高。
MAP2-3 免疫接种可有效诱导记忆 B 细胞和记忆 T 细胞。
