A novel and efficient method to induce allospecific CD8(+) memory T lymphocytes

The aim of the current study was to establish a simple method for effectively inducing memory T lymphocytes by the intraperitoneal injection of spleen lymphocytes into mice. In total, 75 mice were divided into the following groups: an injection group administered three doses of spleen lymphocytes (1 × 10(6), 5 × 10(6), and 1 × 10(7) cells), a transplantation group in which a 0.25‐cm(2) skin section from C57BL/6 mice was transplanted onto the back of the recipient, and a control group in which an equal volume of phosphate‐buffered saline was injected. At 1, 2, or 3 months following transplantation, the following parameters were evaluated: quantity of T lymphocytes, percentage of cluster of differentiation 8(+) (CD8(+)) memory T cells, and proliferation index of purified CD8(+) memory T cells. No significant differences among groups were detected at 1 month (p > .05). However, the injection group administered 1 × 10(6) cells exhibited the highest proportion of CD8(+) memory T cells among all groups at 2 months, and the proportions of CD8(+) T cells were higher in the three injection groups than in the skin transplantation and control groups at 3 months. The proportions of memory T cells were higher in the injection groups administered 5 × 10(6) or 1 × 10(7) cells than in the skin transplantation and control groups at 3 months. The newly established method effectively induces memory T lymphocytes via the intraperitoneal injection of spleen lymphocytes in vivo and has potential applications in the field of immunotherapy.