According to a new study, immune cells like dendritic cells, which are essential for the immune system’s activation, recover more slowly the more serious the COVID-19 infection is (Figure 1). They were able to demonstrate that multiple different immune cell types were still negatively impacted six months after a severe COVID-19 infection. They found parallels between what occurs to immune cells in conditions including cancer and HIV, continuing immunological activation, and chronic infections in the body.
The innate immune system, which is required for the body to form any sort of particular immunological response at all, has been the focus of the researchers’ deeper examination in this work. The immune system must recognise a novel virus when it enters the body for the first time, as SARS-CoV-2 at the start of the epidemic. Dendritic cells, a kind of cell group, are required for this to occur. These in turn stimulate T cells that can destroy SARS-CoV-2-infected cells and B cells that can create antibodies that can neutralise the virus. In order to connect the innate and adaptive immune systems, dendritic cells are essential.
In their investigation, researchers found a relationship between the severity of an illness and its impact on dendritic cells. Additionally, it was demonstrated that six months later, there is still a difference in the distribution of the various monocyte subtypes among patients and the healthy control group. The change in monocytes, in particular in the lungs, suggests that the body is still healing from a significant sickness, according to the experts.
Journal article: Francis R. Hopkins, F.R., et al., 2023. Major alterations to monocyte and dendritic cell subsets lasting more than 6 months after hospitalization for COVID-19. Frontiers in Immunology.
Summary by Stefan Botha