Table 1.

Recipient pretreatment with immature donor DC+anti-CD40L mAb markedly increases the incidence of apoptotic cells in graft-infiltrating and spleen cell populations

Cells	Treatment	% apoptotic cells
GICa	Normal	5.5±2.3b
	Untreated	14.8±2.6
	Mature DC	7.9±1.5
	Immature DC	18.6±3.8
	Immature DC+anti-CD40L mAb	30.6±2.7
Spleen cells	Normal	4.5±2.7c
	Untreated	14.8±5.6
	Mature DC	7.2±2.4
	Immature DC	18.2±6.2
	Immature DC+anti-CD40L mAb	32.4±8.6

^aGIC, Graft-infiltrating cells.

^bDetermined by TUNEL staining.

^cDetermined by spectrofluorometric DNA fragmentation assay.

C3H mice received either no treatment, or 2 × 10⁶ mature B10 DC, or 2 × 10⁶ immature B10 DC ±200 μg anti-CD40L mAb, 7 days before heterotopic vascularized B10 heart transplant. Seven days post-transplant, heart graft-infiltrating cells were isolated, as described in Materials and Methods, and stained for apoptosis by TUNEL. The incidence of TUNEL⁺ cells in counts of 500 cells was determined by a “blinded” observer. Spleen cell suspensions were prepared at the same time, cultured overnight in complete medium, and DNA fragmentation determined by spectrofluorometric assay, as described in Materials and Methods. Results as means ±1 SD obtained from groups of three animals.