The anti-SARS-CoV-2 BNT162b2 vaccine suppresses mithramycin-induced erythroid differentiation and expression of embryo-fetal globin genes in human erythroleukemia K562 cells

The COVID-19 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) the ongoing coronavirus disease 2019 (COVID-19) pandemic. The SARS-CoV-2 Spike protein (S-protein) plays an important role in the early phase of SARS-CoV2 infection through efficient interaction with ACE2. The S-protein is produced by RNA-based COVID-19 vaccines, and has been hypothesized to be responsible for damaging cells of several tissues and for some important side effects of RNA-based COVID-19 vaccines. The aim of this study was to verify the effect of the BNT162b2 vaccine on erythroid differentiation of the human K562 cell line, that has been in the past intensively studied as a model system mimicking some steps of erythropoiesis. We found that the BNT162b2 vaccine suppresses mithramycin-induced erythroid differentiation of K562 cells. Reverse-transcription-PCR and Western blotting assays demonstrated that suppression of erythroid differentiation was associated with sharp inhibition of the expression of α-globin and γ-globin mRNA accumulation. Inhibition of accumulation of ζ-globin and ε-globin mRNAs was also observed. In addition, we provide in silico studies suggesting a direct interaction between SARS-CoV-2 Spike protein and Hb Portland, that is the major hemoglobin produced by K562 cells. This study thus provides information suggesting the need of great attention on possible alteration of hematopoietic parameters following SARS-CoV-2 infection and/or COVID-19 vaccination. ### Competing Interest Statement The authors have declared no competing interest.