Frequencies of regulatory CD4⁺ T cells after progesterone treatment and IV SIVmac239 challenge.

<p>A) Percentages of CD4⁺ CD152⁺ T cells in PBMC. B) Percent of CD4⁺ FoxP3⁺ HLA-DR⁺ T cells after challenge in PBMC. C) Percentages of CD4⁺ CD152⁺ T cells in axillary LN of the vaccinated animals at 12 weeks post-challenge. D) Percentages of CD4⁺ FoxP3⁺ HLA-DR⁺ T cells in axillary LN of the vaccinated animals at 12 weeks post-challenge. (λ) Naïve control macaques (n = 7), (○) SHIV-immunized macaques (n = 5) and (5) Depo-Provera®-treated, SHIV-immunized macaques (n = 6).