Change in peripheral blood lymphocyte count in dogs following adoptive immunotherapy using lymphokine-activated T killer cells combined with palliative tumor resection

• Change in peripheral blood lymphocytes in dogs following adoptive immunotherapy using lymphokine-activated T killer cells in combination with surgery was evaluated.
• A single administration of lymphokine-activated T killer cells combined with surgery may increase peripheral blood T lymphocytes, particularly CD8+ cells, in tumor-bearing dogs.
• The sequential administration of lymphokine-activated T killer cells combined with surgery may keep increased count of peripheral blood CD8+ cells in tumor-bearing dogs.

We evaluated changes in peripheral blood lymphocyte (PBL) count in dogs following adoptive immunotherapy using lymphokine-activated T killer cells (T-LAK) in combination with surgery. Fifteen tumor-bearing dogs treated with T-LAK therapy combined with palliative resection of tumors were enrolled in the present study. T-LAK were generated from autologous peripheral blood mononuclear cells (PBMC) by culture with recombinant human interleukin −2 (rhIL-2) and solid phase anti-canine cluster of differentiation (CD)3 antibody. T-LAK were administrated intravenously at 2–4-week intervals. After the first administration of T-LAK, counts of PBL and T lymphocyte subsets (CD3+, CD4+ and CD8+ cells) increased and the CD4/CD8 ratio decreased, with significant increases in CD8+ cells (P < 0.05). In 8 tumor-bearing dogs that were administered sequential T-LAK, available data on changes in PBL and T lymphocyte phenotypes until the fifth administration were also analyzed. In tumor-bearing dogs administered 5 rounds of T-LAK, CD8+ cell counts were maintained high until the fifth administration of T-LAK. Moreover, the CD4/CD8 ratio remained low until the fifth administration of T-LAK. These results indicate that T-LAK therapy combined with surgery may increase peripheral blood T lymphocytes, particularly CD8+ cells, in tumor-bearing dogs.