The alarmism and hysteria about the relatively harmless SARS-CoV-2/Covid-19 continues.
At least we are learning more about virus infections and how the human immune system responds etc.
What they don't tell you is whether for example a severe common cold (coronavirus and rhinovirus) or flu does not do the same kind of changes. If yes, then what is different?
"Severe COVID-19 infection triggers changes that affect gene expression in immune system stem cells, causing long-lasting alterations in the body’s immune response, according to a new study ...
Research on hematopoietic stem cells, which are most abundant in bone marrow, has been limited by the costly and invasive techniques required to profile these cells. However, using their novel approach for isolating, enriching and studying hematopoietic stem cells circulating in the blood, the team demonstrated that these hematopoietic stem and progenitor cells – 0.05% of all circulating peripheral blood mononuclear cells – capture the full cellular diversity of their bone marrow counterparts. This revelation opened the doors to study, at single cell resolution, how stem cells are affected upon infection and vaccination with a simple blood draw. ..."
From the highlights and abstract:
"Highlights
• Severe COVID-19 programs durable epigenetic changes and hyper-activation in monocytes
• Circulating HSPC capture post-COVID-19 changes in hematopoiesis and stem cell programs
• Post-COVID-19 HSPC convey epigenetic and transcriptional memory to mature progeny cells
• IL-6 contributes to epigenetic reprogramming of mouse and human HSPC and myeloid cells
Summary
Inflammation can trigger lasting phenotypes in immune and non-immune cells. Whether and how human infections and associated inflammation can form innate immune memory in hematopoietic stem and progenitor cells (HSPC) has remained unclear. We found that circulating HSPC, enriched from peripheral blood, captured the diversity of bone marrow HSPC, enabling investigation of their epigenomic reprogramming following coronavirus disease 2019 (COVID-19). Alterations in innate immune phenotypes and epigenetic programs of HSPC persisted for months to 1 year following severe COVID-19 and were associated with distinct transcription factor (TF) activities, altered regulation of inflammatory programs, and durable increases in myelopoiesis. HSPC epigenomic alterations were conveyed, through differentiation, to progeny innate immune cells. Early activity of IL-6 contributed to these persistent phenotypes in human COVID-19 and a mouse coronavirus infection model. Epigenetic reprogramming of HSPC may underlie altered immune function following infection and be broadly relevant, especially for millions of COVID-19 survivors."
Epigenetic memory of coronavirus infection in innate immune cells and their progenitors (open access)
Graphical abstract
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