Figure 6.

Infection of WT mice with SARS-CoV-2 variants induced pronounced changes in immune cell composition of the lung, even upon limited local replication

(A–J) Flow cytometric analysis of lung single-cell suspensions of the WT mice analyzed in Figure 5: infected i.n. with 10⁴ pfu of indicated SARS-CoV-2 variants 0 days p.i., 3 (n = 3) and 5 (Gamma), or 6 (EU-1, Alpha, Beta) days p.i. (n = 4), analyzed as shown in Figure S3. Shown are mean fold changes in frequency ±SDs of (A) hematopoietic cells, (B) CD8⁺ T cells, (C) PD-1_pos CD8⁺ T cells, (D) CD4⁺ T cells, (E) inflammatory monocytes, (F) neutrophils, (G) CD11b⁺ DCs, (H) inflammatory DCs, (I) pDCs, and (J) NK cells relative to the mean of mock infected WT mice (n = 4, 1). Percentages of immune cells and single mock measurements are shown in Figure S9.

(K–M) Relative amount of (K) IFN-α4, (L) IFN-β, and (M) IFN-λ mRNA quantified by qRT-PCR of lung homogenates relative to the mean of mock infected mice (n = 4) and normalized to GAPDH as housekeeper. Each black dot represents 1 individual animal. Red dashed line or 10⁰ indicates the mean of mock, arbitrarily set to 1. Mean values of K18-hACE2 transgenic (Tg) mice infected with the respective VOCs, as shown in Figure 3, are indicated by colored round symbols. p values were calculated performing a Kruskal-Wallis test with a Dunn’s multiple comparison test (^∗p ≤ 0.05).