Infused HIV-specific CD8⁺ T-cell clones survey the rectal mucosa. (A-B) Fluorescence images of fresh rectal tissue sections (30 μm) from patient 7707 (A) and 7709 (B) stained with DAPI in blue, CD8 in green and Qdot655 multimer A*0301/QVPLRPMTYK-HIV-NEF for patient 7707 and Qdot655 multimer B*2705/KRWIILGLNK-HIV-GAG for patient 7709 in red. Arrows indicate Qdot655⁺CD8⁺cells (yellow). Inset percentage values reflect Qdot655⁺CD8⁺ T cells as a percent of total CD8⁺ T cells. (C) Cryopreserved rectal tissue sections stained concurrently with CD8 and the corresponding HIV-specific Qdot655 multimer B*0801/GEIYKRWII-HIV-GAG for 7702 and 7703; B*0702/IPRRIRQGL-HIV-ENV for 7705. Ten fields of 1 mm² spanning 2 rectal biopsies per time point were enumerated for CD8⁺Qdot655⁺ T cells and results expressed as a percentage of total CD8⁺ T cells. (D) Fluorescence images of cryopreserved rectal tissue sections (7 μm) from patient 7702 stained with DAPI in blue, CD8 in green, and Qdot 655 multimer. B*0801/GEIYKRWII-HIV-GAG in red. Inset values represent the average of 10 counted fields. (E) Frequencies of HIV-specific T cells in rectal biopsies for patients 7701, 7704, and 7707 expressed as a percent HIV-specific Vβ copies relative to CD8β copies. Results are an average of 2 independent rectal samples taken at each time point. (F) CMV-specific CD8⁺ T cell clones quantified in rectal biopsies from patients 7701 and 7707 (TCR-specific RT-PCR) and CMV-specific CD8⁺ T-cell clones in rectal biopsies from patients 7702, 7703, and 7707 (specific Qdot655 multimers). One-tailed, paired Student t tests were used for statistical analysis.