Localization and phenotype of pDC in HIV⁺ human spleens. (A) Comparative distribution of pDCs on serial sections from HIV⁻ patient A (right panels) and HIV⁺ patient M (except for CD3/BDCA2 labeling done in patient N, left panel), both with ITP. Original magnification, ×100; inset, ×400. Results are representative of those found in 6 HIV⁻ and 7 HIV⁺ patients. (B) pDCs have a nonactivated phenotype in HIV⁻ and HIV⁺ patients. Serial spleen sections were labeled with CD83 and CD123 (left panels), CD86 and CD123 (right panels) in HIV⁻ patient C (top panels), HIV⁺ group 1 patient O (middle panels), and HIV⁺ group 2 patient S (bottom panels). Original magnification ×100; bottom panels, ×200. (C) pDC accumulation in HIV⁺ patient S from group 2. Original magnification ×100; inset, ×400. (D) Most HIV⁺ patients, not HIV⁻ patients, have IFN-α–producing cells in the marginal zone. Serial spleen sections were labeled for IFN-α and BDCA2, CD11c, CD68, CD20, or CD14. Sections from HIV⁻ patient A (i,ii) and from HIV⁺ patients R (iii-v), M (vi,ix), and O (vii,viii). Original magnification ×100; insets, ×400; v, ×400. Pictures are representative of 4 HIV⁻ and 6 HIV⁺ patients.