T-cell receptors (TCR) and B-cell receptors (BCR) are unique proteins on immune cells that recognize specific threats. Sequencing all of them reveals your immune system's diversity (how many different threats can you respond to) and clonality (is one clone dominating, suggesting active immune response).
Reading this chart
Y-axis shows TCR diversity (Shannon index). The drop from 4.2 to 3.1 means the immune system's ability to recognize diverse threats shrank by ~25%. Lower diversity = more vulnerable to novel infections. The slow recovery shows immune reconstitution takes months.
Reduced TCR/BCR diversity = immunosuppression (fewer unique threats recognizable). Increased clonality = the immune system is actively fighting something (one clone expanding). T-cell frequency reduction during flight = suppressed adaptive immunity.
Diversity indices (Shannon, Simpson), clonality scores (1 - normalized Shannon entropy), clone frequency distributions. Standard ecological diversity metrics applied to immune sequences.
All AP-level math. No differential equations, no ML required. With n=4, descriptive statistics are more honest than hypothesis testing.
T-cell frequencies reduced during flight
Cytotoxic T-cell function suppressed
TCR diversity showed transient reduction
Recovery of immune repertoire post-flight
Core component of Immune Regulation domain score. Diversity drop + T-cell frequency reduction = quantifiable immune suppression. Clonality changes add nuance about active vs. passive immune states.