Mantile Francesca, Capasso Angelo, De Berardinis Piergiuseppe, Prisco Antonella
Institute of Genetics and Biophysics, CNR, 80131 Naples, Italy.
IBBC, CNR, 80131 Naples, Italy.
Microorganisms. 2020 Apr 14;8(4):564. doi: 10.3390/microorganisms8040564.
Immunological memory can be defined as the ability to mount a response of greater magnitude and with faster kinetics upon re-encounter of the same antigen. We have previously reported that a booster dose of a protein antigen given 15 days after the first dose interferes with the development of memory, i.e., with the ability to mount an epitope-specific IgG response of greater magnitude upon re-encounter of the same antigen. We named the time-window during which memory is vulnerable to disruption a "consolidation phase in immunological memory", by analogy with the memory consolidation processes that occur in the nervous system to stabilize memory traces. In this study, we set out to establish if a similar memory consolidation phase occurs in the IgG response to a B cell epitope displayed on a filamentous bacteriophage. To this end, we have analyzed the time-course of anti-β-amyloid IgG titers in mice immunized with prototype Alzheimer's Disease vaccine fdAD(2-6), which consists of a fd phage that displays the B epitope AEFRH of β -amyloid at the N-terminus of the Major Capsid Protein. A booster dose of phage fdAD(2-6) given 15 days after priming significantly reduced the ratio between the magnitude of the secondary and primary IgG response to β-amyloid. This analysis confirms, in a phage vaccine, a consolidation phase in immunological memory, occurring two weeks after priming.
免疫记忆可定义为再次遇到相同抗原时产生更强且动力学更快的反应的能力。我们之前报道过，在首剂接种15天后给予蛋白抗原加强剂量会干扰记忆的形成，即再次遇到相同抗原时产生更强的表位特异性IgG反应的能力。我们将记忆易受破坏的时间窗命名为“免疫记忆巩固期”，这是类比神经系统中发生的记忆巩固过程来稳定记忆痕迹。在本研究中，我们着手确定在对丝状噬菌体展示的B细胞表位的IgG反应中是否发生类似的记忆巩固期。为此，我们分析了用原型阿尔茨海默病疫苗fdAD(2 - 6)免疫的小鼠中抗β - 淀粉样蛋白IgG滴度的时间进程，该疫苗由一种在主要衣壳蛋白N端展示β - 淀粉样蛋白B表位AEFRH的fd噬菌体组成。在初次免疫15天后给予噬菌体fdAD(2 - 6)加强剂量显著降低了对β - 淀粉样蛋白的二次和初次IgG反应强度之比。该分析证实，在噬菌体疫苗中，免疫记忆巩固期在初次免疫两周后出现。
