Tumor-specific T cells signal tumor destruction via the lymphotoxin β receptor

Table 2 The effect of LT-βR-Fc fusion protein administration on adoptive immunotherapy.

Adoptive immunotherapy ^a				Mean number of pulmonary metastases ^b
Donor	Hosts	Number of T cells transferred	Blocking proteins^b	Exp.1	Exp.2	Exp.3	Exp.4
None	wt	0	none	250	250
wt	wt	35	hu IgG	21(5)^d	52(13)^d
wt	wt	35	LTβR-Fc	33(6)^d	78(11)^d
wt	GKO	0	None	243(60)	244(60)	250	250
GKO	GKO	35	hu IgG	6(3)^d	88(23)^d	85(12)^d	90(30)^d
GKO	GKO	35	LTβR-Fc	9(3)^d	211(56)^e	250^e	250^e

a) Mice were vaccinated s.c. with D5-G6 tumor cells and TVDLN were harvested 8 days later. Lymph node cells were stimulated in vitro with anti-CD3 for two days and then expanded for three days in 60 IU/ml IL-2. Effector cells were harvested and 35 × 10⁶ T cells were adoptively transferred into animals with established 3-day D5 pulmonary metastases. IL-2 (90,000 IU) was administered daily i.p. for four consecutive days following adoptive transfer.
b) Purified control human IgG or LT-βR-Fc (250 μg) was directly administered i.v. after adoptive transfer of the TE and for the following 3 days once per day.
c) Mice were sacrificed 13 days following i.v. inoculation of tumor and the number of pulmonary metastases enumerated in a blinded fashion. Results presented are the mean of 5 mice. Metastases that were too numerous to count accurately were known to be greater than 250 metastases and were assigned a value of 250.
d) p < 0.05 compared to IL-2 alone treated controls.
e) p > 0.05 compared to IL-2 alone treated controls.

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