Table 1.

B cells and CD4⁺ T cells but not CD8⁺ T cells are needed for successful adoptive immunotherapy of LCMV-WE carrier mice

Exp.	Transferred lymphocytes	Days after transfer	Virus titer
			Blood	Brain	Spleen	Kidney
1	d60 immune cells	20	<1.8	<1.9	<2.1	4.8
	d8 immune cells	20	2.6 ± 0.6	4.5 ± 0.6	4.4 ± 0.3	5.8 ± 0.2
	None		6.9 ± 0.3	6.2 ± 0.2	6.0 ± 0.3	7.1 ± 0.4
	d60 immune cells
2	anti-CD8 + C′ treated	90	<1.8	<1.8	<2.2	3.4 ± 0.3
	anti-CD4 + C′ treated	90	5.7 ± 0.1	4.6 ± 0.3	5.6 ± 0.3	6.6 ± 0.2
	anti-B cell + C′ treated	90	4.2 ± 0.3	5.1 ± 0.4	5.3 ± 0.4	6.3 ± 0.3
3	CD8 depleted	40	<1.7	<2.0	<2.0	4.4 ± 0.2
	CD4 depleted	40	2.3 ± 0.6	2.5 ±0.3	3.5 ± 0.7	5.3 ± 0.2
4	CD4+ plus CD8+ cells	40	4.6 ± 0.1	5.5 ± 0.1	6.5 ± 0.1	6.8 ± 0.1
	CD8+ plus B cells	40	3.8 ± 0.4	4.7 ± 0.1	5.7 ± 1.1	5.9 ± 0.1
	CD4+ plus B cells	40	<1.7	<2.0	<2.1	4.5 ± 0.3

C57BL/6 mice were infected i.v. with 200 pfu of LCMV-WE. Spleen cells (10⁸) of these mice were taken either 8 days (d8 immune cells) or 60 days after infection (d60 immune cells), and cells were adoptively transferred to C57BL/6 LCMV-WE-infected carrier mice. 

 Virus titers are expressed as plaque-forming units per gram of organ or per milliliter of blood (log₁₀ + SEM) and are means ± sem of four mice. Experiments were repeated at least twice with similar results. In experiment (Exp.) 2, either CD4⁺ or CD8⁺ T cells or B cells were depleted with mAbs and complement. In experiment 3, CD4⁺ or CD8⁺ T cells were depleted with the use of magnetic beads. Cell depletion efficacy was >95%. In experiment 4, CD4⁺ T cells, CD8⁺ T cells, and B cells were purified by magnetic beads. Then, 5 × 10⁶ CD4⁺ T cells, 5 × 10⁶ CD8⁺ T cells, and 1 × 10⁷ B cells (previously determined as minimally necessary numbers of cells) were injected in various combinations into LCMV-WE carriers. The purity of the enriched spleen cell populations was >95% for B and CD4⁺ T cells and 80–85% for CD8⁺ T cells.