Fig. 5

Cartoon Illustration of the Establishment of the CD4+ T-Cell Pool. N: naïve T-cell pool size, M: memory T-cell pool size, σ: Thymus production of naïve T-cells, α: activation of naïve T-cells that acquire a memory phenotype, dN: naïve T-cell death, dM: memory T-cell death, pN: naïve T-cell proliferation, p0N: maximum proliferation of naïve T-cells, p0M: maximum proliferation of memory T-cells, h: pool size at half maximum proliferation; r: clonal size resulting from activation of a single naive T cell