Figure S3.

Increased T reg Cells but No Differentiation into TFR Cells in COVID-19 Lymph Nodes, Related to Figure 3

(A) Representative multi-spectral 7 color immunofluorescence images showing CD4 (red), CD19 (green), CXCR5 (purple), Bcl6 (white), FoxP3 (yellow), IgG (light blue) and DAPI (blue) staining of lymph nodes from late COVID-19 patients. Images in the green box show high-power images. No FoxP3⁺/Bcl6⁺ cells were seen (white staining with no yellow overlap) in follicles.

(B) IgG⁺ plasmablasts are found in follicular and extra-follicular areas in COVID-19 lymph nodes. Related to Figure 3. Representative multi-color immunofluorescence images of Bcl6 (white) and IgG (light blue) in lymph nodes of a late COVID-19 patient (left) and a control (right). IgG⁺ cells were abundant in follicular and extrafollicular areas in both COVID-19 lymph nodes and controls.

(C and D) Large increase in TNF-α production at both follicular and extra-follicular sites in COVID-19 lymph nodes, while controls have low levels of TNF-α localized to follicles. Related to Figure 3.

(C) Representative multi-color immunofluorescence images of TNF-α (green) and DAPI (blue) staining in lymph nodes from early and late COVID-19 patients and a control. (D) Absolute numbers (left) and percentages (right) of TNF-α+ cells in lymph nodes from early (purple) (n = 5) and late (red; n = 6) COVID-19 patients and controls (blue; n = 10). Multiple comparisons were controlled for by Kruskal-Wallis test. Error bars represent mean ± SEM. ^∗p < 0.05; ^∗∗p < 0.01.