Figure 4: CD8⁺ memory T cell activation and function in Neuro-PASC.

A.) Selected FACS plots showing CD8 TEM cells are less activated in NP vs. CC groups after S and N peptide pool stimulation. B.) Quantification of AIM+ CD8 TEM cells after S, N, and M peptide stimulation. C.) CD8⁺ TEMRA cells accumulate significantly in PBMC from NP subjects compared with CC or HC. D.) CD8⁺ TEMRA cells from NP patients are less activated by S3/4 and N pools compared with those from CC subjects. E.) Quantification of AIM⁺ CD8⁺ TEMRA cells from D. F-G.) CD8⁺ TEM from NP have significantly enhanced IL-6 production after S3/4 stimulation compared with CC. H.) Pie charts demonstrating that S3/4-specific CD8⁺ TEM are polarized to produce more TNF-α or granzyme B in CC group while those from NP patients produce significantly more IL-6 and Perforin. I.) CD8⁺ TEMRA from NP patients have elevated granzyme and Perforin production after S3/4 stimulation compared to CC subjects. J.) CD8⁺ TEMRA from CC subjects are less polyfunctional in response to S3/4 stimulation compared with NP subjects. Data combined from 5 independent experiments with n=34 NP, n=11 CC. *p<0.05, **p<0.01 using two-tailed Student’s t test with Welch’s correction (B, C, E, G, I) or Permutation test (H, J). All pie graphs are showing data after subtracting background (unstimulated condition; Fig. S6 B–C).