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We studied the phenotype and antitumor cytolytic activity of splenocytes from mice with K-1735 pulmonary metastases and tumor-infiltrating lymphocytes (TILs) from these metastases following treatment with anti-CD3, IL-2, and TNF combination immunotherapy. Mice were injected with 5 x 10(4) tumor cells and received a single 5 micrograms i.p. dose of anti-CD3 on day 3, followed by either IL-2 alone or fourfold less IL-2 with TNF (25,000 U/day) given at 3-day intervals. A single dose of anti-CD3 followed by low-dose IL-2 and TNF caused the greatest reduction in metastases compared to anti-CD3 alone, higher doses of IL-2 alone, or IL-2 + TNF. Reduction in metastases (greater than 80%) using the three agents was equal to or exceeded that achieved by ninefold higher concentrations of IL-2 alone. Treatment with anti-CD3 + IL-2 and TNF significantly prolonged survival, and resulted in 60% of mice achieving long-term survival greater than 120 days. This was superior to single agents or other combinations with the three agents causing a synergistic rather than additive effect. The anti-CD3-activated splenocytes were a heterogeneous population of T cells, with an increased number of CD8+ cells compared to splenocytes from mice treated with high doses of IL-2 alone. Analysis of TILs showed a greater proportion of CD8+ cells in anti-CD3-treated mice compared to IL-2 alone, but a lower proportion of CD4+ cells. Lymphokine-activated killer (LAK) and natural killer (NK) activities of both splenocytes and TILs in vitro increased following anti-CD3/IL-2 + TNF treatment, and were consistently greater than that generated with four times more IL-2 alone. TNF appeared to potentiate cytolytic activity rather than affect phenotypic changes. These results indicate that the sequential use of anti-CD3, IL-2, and TNF for LAK induction and maintenance potentiates antitumor activity, and suggests novel strategies for combination immunotherapy.

METHODS: 26 dogs underwent bypass; temperature was raised to 42 C in 14 dogs (heat-shocked HS) or maintained at 37 C in 12 dogs (nonheat-shocked NHS). After 12 or 24 hours, heart rate (HR), left ventricular pressure (LVP), and peak +dP/dT were measured, as well as preload recruitable stroke work relationship (PRWA) throughout reperfusion. Myocardial expression of hsp70i was quantified by Western blots.

RESULTS: No significant differences in preoperative comorbidities were identified between the two groups. Median length of stay was 12 days for both groups. (p 0.42) There were no differences in sepsis (p 0.47), pneumonia (p 0.19), prolonged intubation (p 0.27), anastomotic leak (p 0.56), reintubation (p 1.0), and readmission (p 0.37) between the two groups. The open group had a decreased incidence of atrial arrhythmia requiring treatment (p 0.04). Overall 30 day mortality was 2% and was similar in both groups. (p 1.0).