Effects of Low-dose Splenic Irradiation on T lymphocyte Immune Function

Relevant studies have confirmed that the stimulation of spleen function caused by low-dose splenic irradiation can have positive effects on tumors and other diseases. This study aimed to determine radiation-induced changes in spleen index, lymphocyte subsets, spleen cell apoptosis, and pathological features of the spleen in mice. The mouse model was established by irradiating the spleen at different doses. The mice were divided into the following groups: blank control, low-dose, low-dose fractionated irradiation, and challenge dose irradiation. The mice were sacrificed under humanitarian conditions, and spleen tissue and peripheral blood were collected. The spleen index was calculated, and flow cytometry was used to analyze spleen T lymphocyte subsets and spleen apoptosis. The pathological changes in the spleen were determined by hematoxylin and eosin (H&E) staining. The spleen index of mice in the low-dose fractionated irradiation group was significantly increased compared with that in the blank control group. The spleen indexes of the low-dose irradiation and low-dose fractionated irradiation groups were much higher than that of the challenge dose irradiation group. Compared with the blank control group, the percentage of CD3+ and CD4+ T lymphocytes in the peripheral blood and spleen tissues in the low-dose irradiation and low-dose fractionated irradiation groups was significantly increased, whereas that from the challenge dose irradiation group was obviously decreased. CD8+ T lymphocytes in the peripheral blood and spleen tissues in the low-dose irradiation, low-dose fractionated irradiation, and challenge dose irradiation groups were significantly lower than those in the blank control group. The apoptosis rate of the spleen in the challenge dose irradiation group was significantly higher than that in the blank control, low-dose irradiation, and low-dose fractionated irradiation groups. H&E staining analysis of the spleen showed pathological changes in the different irradiation groups compared with the blank control group. Low-dose irradiation and low-dose fractionated irradiation can change the T lymphocyte subsets in the peripheral blood and spleen of mice, which can promote immune excitation and improve immune effects.