Journal Summaries in Gastroenterology
HBV vaccination and HBV infection induces HBV-specific natural killer cell memory
Gut — Wijaya RS2, Read SA, Truong NR, et al. | April 01, 2020
The identification of antigen-specific memory natural killer cells (mNKs) in mice and non-human primates has challenged the view that vaccination against hepatitis B virus (HBV) confers protection from subsequent infection through immunological memory that is traditionally considered the domain of the adaptive immune system. Researchers examined humans for the existence of HBV-specific mNKs after vaccination and in chronic HBV infection. Flow cytometry and ELISA were used to evaluate NK cell responses following challenge with HBV antigens in HBV vaccinated, non-vaccinated and chronic HBV-infected individuals. They observed higher cytotoxic and proliferative responses against autologous hepatitis B surface antigen (HBsAg)-pulsed monocyte-derived dendritic cells (moDCs) in NK cells from vaccinated subjects vs unvaccinated subjects. Moreover, significantly higher NK cell lysis of HBsAg-pulsed moDCs was observed relative to that of hepatitis B core antigen (HBcAg)-pulsed moDCs (non-vaccine antigen) or tumor necrosis factor α-activated moDCs in a NKG2D-dependent manner. Further, greater degranulation against HBcAg-pulsed moDCs was observed in mNKs from chronic hepatitis B patients vs unvaccinated or vaccinated patients. Notably, there was a negative correlation of mNK activity with HBV DNA levels. Data suggest the existence of a mature mNKs following HBV antigen exposure either through vaccination or infection. For developing novel treatments targeting HBV in chronic infection, harnessing these antigen specific, functionally active mNKs provides an opportunity. 作者: StephenW 时间: 2020-4-2 16:57