Table 1.

CD4+ T cell profiles in HIV-1-negative individuals

Patient	Sample	CD4+ T cell, count/mm3 blood	CD4+ T cell count, LT/μg	CD45 RA+ CD4+ T cells in LT, %	Ki67+ CD4+ T cells in LT, %	TUNEL+ CD4+ T cells in LT
1	Lymph node	NT	314	41	0.32	0.3
2	Tonsil	NT	357	38	0.1	0.02
3	Tonsil	1,097	371	54	0.35	0.2
4	Tonsil	1,192	286	48	0.42	0.15
5	Tonsil	621	271	NT	0.6	0.5
	Mean	970	320	45	0.4	0.2

The number of CD4+ T cells/mm³ in blood was determined by FACS analysis (NT, not tested). The CD4+ T cell count per microgram in LT was determined by QIA of sections in which CD4+ T cells had been stained immunohistochemically. At least 20 sections distributed throughout the tissue specimen were examined at a magnification of ×160, and the number of CD4+ T cells was determined at least twice, with values that agreed to within ±5%, in representative fields that had well defined lymphoid follicles and paracortical regions. The microgram of LT was determined from the area examined (3.75 × 10⁻³ cm² at ×160) the section thickness (5 × 10⁻⁴ cm) × the previously determined (1) density of ≈1 gm/cm³. The percentage of CD45RA+ CD4+ T cells was determined by manually counting ≈1,000 double-labeled cells. The percentage of CD4+ T cells undergoing proliferation or apoptosis was determined by double labeling with first anti-CD4+ and then anti-Ki67 or TUNEL assay, respectively, as described in Materials and Methods. Single- and double-positive CD4+ T cells were quantitated by QIA and binary multiplication. An average of 3,680 CD4+ cells was counted to determine the percentage of double-positives.