Figure 4.

Modulation of NK cells expressing activating and inhibitory receptors by multiple doses of the BNT162b1 vaccine. Summary results indicating percentages and absolute numbers of NK cells expressing the 2DS1, 2DS2 and 2DS4 activating (A) or the 2DL1 and ILT-2 inhibitory KIR receptors (B). Individuals who had never been SARS-CoV-2-infected and received three doses of the BNT162b1 mRNA vaccine were analyzed at different time points: baseline (immediately before the first inoculation (white triangle) (T0), 7 (T1) and 21 (T2) days after initial inoculation, one (T3), three (T4) and six (T5) months after the first vaccine booster (grey triangle), and, finally, ten days after the second vaccine booster (black triangle) (T6). Boxes stretch from the 25th to the 75th percentile. Lines across the boxes indicate the median values. Lines stretching from the boxes indicate extreme values. Statistical significance is shown; **p<0,05. (C) Gate strategy used to identify NK cell subsets. (a) Lymphocyte selected by forward (FS) and side scatter (SS) properties (Gate Lymphocyte). (b) The CD3+CD19+ vs. the SS dot plot allows the discrimination of T and B lymphocytes (Gate J); the remaining double negative cells (Gate CD3-CD19-) were analyzed within a CD56 vs. CD16 dot plot (c) leading to the identification of NK cells (Gate Natural Killer); (d1-d5) histograms representing the activating (2DS1,2DS2 and 2DS4) and inhibitory (2DL1 and ILT-2) receptors expressed by NK.