Figure 4.

Cxcr5^fl/flCd4^cre/+ Mice Have an Intact GC Response after Influenza Infection

Analysis of the GC response in Cxcr5^fl/flCd4^cre/+ mice 14 days after influenza A virus (HKx31) infection.

(A) Representative histogram of CXCR5 expression in Foxp3⁺CD4⁺ Treg cells and B220⁺ B cells.

(B) Quantification of the MFI (geometric mean) of CXCR5 in Foxp3⁺CD4⁺ Treg cells.

(C) Representative histogram of CXCR5 expression in Foxp3⁻CD4⁺ T cells and B220⁺ B cells.

(D) Quantification of the MFI (geometric mean) of CXCR5 in Foxp3⁻CD4⁺ T cells.

(E) Flow cytometry contour plots of GC B cells, gated as Bcl6⁺Ki67⁺ cells of B220⁺ cells.

(F and G) Quantification of the (F) frequency and (G) absolute number of Bcl6⁺Ki67⁺ B cells.

(H and I) Quantification of the (H) percentage and (I) number of Bcl6⁺PD-1⁺Foxp3⁻CD4⁺ Tfh cells.

(J and K) Quantification of the (J) percentage and (K) number of Bcl6⁺PD-1⁺Foxp3⁺CD4⁺ Tfr cells.

(L) Cryosections were stained for Foxp3 (magenta), Ki67 (blue), CD3 (green), and IgD (orange). Scale bar, 100 μm. Representative confocal image of the GC, with Tfr cells and Tfh cells indicated by the arrows.

(M) Quantification of the median number of Tfr cells, defined as CD3⁺Foxp3⁺ cells, per 5,000 μm².

(N) Quantification of the median number of Tfh cells, defined as CD3⁺Foxp3⁻ cells, per 5,000 μm².

Each symbol represents one mouse, the horizontal bars represent mean values, and the error bars show the SD. The p values were determined using a Mann-Whitney U test. For the quantification of confocal images, 4–10 GCs were imaged per mouse. Data represent two independent experiments.