Fig. 7: Absence of IFN-gR1 dampens maternal SARS-CoV-2 vaccination-induced neuronal proliferating and differentiation.

a Quantification of IFN-γ protein levels in peripheral blood in dams after SARS-CoV-2 vaccination (left) and their pup’s brain (right) (n = 5 dams/group; n = 6 pups/group). b IFN-gR1 transcription in different cell populations in CNS of rodent and human beings. c IFN-gR1 transcription in microglia/macrophages during development in rodent. d Schematic representation of the strategy to deplete IFN-gR1 in CNS-resident microglia of pups, PBS, or SARS-CoV-2 vaccine (50 μL,100 μL, i.m.) administration at E14.5, and 4-OHT administration at P7 to P9 (1 mg/kg, 3 i.p.  injection). Representative images of microglia contacted proliferating cells (e) and quantification (f) in controls and SCV pups after conditional IFN-gR1 knockout, one dot represents one microglia, n = 4 pups/group. Scale bar represents 50 μm. Representative images of proliferating cells (BrdU⁺, red in g) and newborn neurons (BrdU⁺DCX⁺ in h) in pups from e. Scale bars: 200 μm (left) and 50 μm (insert boxes) in g and h. Quantification of BrdU⁺ cells (i) and BrdU⁺DCX⁺ cells (j) in pups related to g and h (n = 4 pups/group). NOR task (k) and Y maze test (l) for short-memory assessment were performed in pups from SCV dams and the controls after IFN-gR1 deficiency in microglia. New: novel object. Old: old object in k, n = 22 pups (Control group), n = 17 (SCV-50 μL and SCV-100 μL groups). New: novel arm. Old: old arm in l, n = 10 pups/group. Statistics calculated by repeated measures ANOVA (a), Student’s t test (f), one-way ANOVA followed by Tukey HSD test (i, j) and paired Student’s t test (k, l). ns: non-significant; *p < 0.05, **p < 0.01, ***p < 0.001. Graphs indicate mean ± s.e.m.