Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock

Chemokine dynamics after mRNA vaccination.

Abstract

AIMS: Since the COVID-19 pandemic, mRNA-based vaccines have gained prominence and opened up new opportunities for vaccine development. Rapid and long-lasting immune responses to antigens are crucial for the success of vaccines. Chemokines, cytokines, and chemokine receptors play an essential role in this process; thus, in this study, we aim to investigate their regulation and the resulting immune cell profile during mRNA-based SARS-CoV2 vaccination. MAIN METHODS: SARS-CoV-2 neutralizing antibody titers were examined by ELISA. Chemokine abundance before and after 2nd dose of the mRNA-1273 vaccine on time points d-1, d+1/2, d+3/4, and d+7 was examined in serum samples using bead-based immunoassays. In addition, flow cytometric analysis of blood samples was performed to characterize chemokine receptor expression on several immune cell populations associated with vaccination success. KEY FINDINGS: Our results demonstrated that mRNA-1273 vaccination increased serum levels of type 1 (IFNgamma), type 2 (IL-4), other pro-inflammatory cytokines (IL-1alpha, IL-1beta) and chemokines (CXCL9, CXCL10, CXCL11, CCL2, CCL4) between day 1 and day 4 post vaccination. Vaccination altered chemokine receptor expression on various cell types. Despite high interindividual differences, enhanced expression was observed for CXCR5 on activated CD4 T cells. Furthermore, CCR5 expression was increased on RBD+ B cells after vaccination, while CCR1, CCR2, CCR4, CCR5, and CXCR5 were elevated on different monocyte subsets. A notable finding was the positive correlation between elevated CXCR4 expression on RBD+ B cells and a high SARS-CoV-2 neutralizing antibody (NAb) titer ratio. SIGNIFICANCE: We here demonstrate a dynamic, cell-specific chemokine regulation early after mRNA booster vaccination. This chemokine modulation likely facilitates an efficient induction of innate immune cell and adaptive T cell responses.