Table 1 Summary of age- associated immune changes in horses versus humans
| Â | Horse | Human | |
A. Lymphocyte Alterations | |||
 Total lymphocyte Count | ↓ | ↓ | |
 B-cell count | ↓ | ↓ | |
 CD4 and CD8 count | ↓ | ↓ | |
 CD4:CD8 | ↑ | ↑ | |
 FOXP3 + CD4 + (T-regulatory) count | ↓ | ↓ | |
 Proliferation | ↓ | ↓ | |
B. Neutrophil Alterations | |||
 Neutrophil count | NC | NC | |
 Adhesion | NC | ↑ | |
 Phagocytosis | NC | ↓ | |
 Chemotaxis | ↑ | ↓ | |
 Oxidative Burst | NC | ↓ | |
C. Unstimulated Cytokines | |||
 TNF-α expression | ↑ | ↑ | |
 IL-6 expression | ↑ | ↑ | |
 IL-8 expression | ↑ | ↑ | |
 IFN-γ expression | ↑ | ↑ | |
 IL-1β expression | ↑ | ↑ | |
 Serum TNF-α | ↑ | ↑ | |
D. Cytokine Responsiveness | |||
| Â | Stimulant | Â | Â |
 TNF-α | LPS, PMA, ionomycin | ↑ | ↑ |
 IFN-γ | LPS, PMA, ionomycin | ↑ | ↑ |