Figure 3.

Brain-Resident CD4 T Cells Acquire a Residency Phenotype In Situ during a Prolonged Brain Transit

(A) Schematic of parabiosis experiments (n = 12,12,18,16,14).

(B and C) Curve of best fit for the origin of conventional (B) T cells or (C) Tregs showing CD69⁻ and CD69⁺ in the blood and brain.

(D) Derived median dwell times.

(E and F) t-SNE of conventional (E) T cells and (F) Tregs built on CD62L, CD44, CD103, CD69, CD25, PD-1, Nrp1, ICOS, KLRG1, ST2, Ki67, Helios, T-bet, and CTLA4. FlowSOM clusters represented in color. Host and incoming cells were defined on CD45.1 versus CD45.2 expression, and are shown at the 2-, 4-, and 8-week time points.

(G and H) CD69 histograms for CD4 conventional (G) T cells and (H) Tregs.

(I and J) Population flow diagrams for conventional (I) T cells and (J) Tregs, in homeostatic state. Circle areas represent population frequencies, calculated independently for blood and brain. Small black circles represent cell death. The size of arrow ends is proportional to the rate of population flow. Numbers display the corresponding entry or exit rate, in events/1,000 cells/day. Numbers with asterisk denote rates with high estimation uncertainty. Population transitions with rates lower than 0.1/1,000 cells/day are not shown.

See also Figure S3.