Department of Microbiology, Kansai Medical University, Hirakata, Osaka, Japan.
Faculty of Bioscience, Nagahama Institute of Bioscience and Technology, 1266 Tamura, Nagahama, Shiga, Japan.
J Radiat Res. 2019 Oct 23;60(5):705-708. doi: 10.1093/jrr/rrz050.
Adult T-cell leukemia is one of the life-threatening diseases that occur in individuals infected with human T-cell leukemia virus type 1 (HTLV-1). Clinical trials of hematopoietic stem cell transplantation therapy are being performed in addition to chemotherapy; however, neither is satisfactory. As a pretreatment for transplantation, anticancer drugs or whole-body irradiation is used to decrease the number of HTLV-1-infected cells, but there are numerous side effects. Therefore, in the present study, using a mouse model of HTLV-1 infection, the long-term survival and number of infected cells in the reservoir organ were investigated in order to determine the effect of γ-irradiation on HTLV-1-infected mice in vivo. There was no improvement in the survival period following γ-irradiation in the γ-irradiated group after HTLV-1 infection when compared with the HTLV-1-infected group. It was also found that the incidence of splenomegaly was ≥80% in the HTLV-1-infected and γ-irradiated group, which was significantly higher than that in the HTLV-1-infected mice. The tissue morphology in the spleen became non-uniform because of γ-rays. Importantly, the number of infected cells in the spleen was increased 4.1-fold in the HTLV-1-infected and γ-irradiated mice compared with that in the HTLV-1-infected mice. Careful consideration might be necessary when using whole-body irradiation in patients with HTLV-1 infection.
成人 T 细胞白血病是感染人类 T 细胞白血病病毒 1 型（HTLV-1）的个体中发生的危及生命的疾病之一。除化疗外，还正在进行造血干细胞移植治疗的临床试验；然而，两者都不尽如人意。作为移植前的预处理，使用抗癌药物或全身照射来减少 HTLV-1 感染细胞的数量，但存在许多副作用。因此，在本研究中，使用 HTLV-1 感染的小鼠模型，研究了体内 γ 射线照射对 HTLV-1 感染小鼠的长期存活和储库器官中感染细胞数量的影响。与 HTLV-1 感染组相比，HTLV-1 感染后 γ 射线照射组的存活期没有改善。还发现，HTLV-1 感染和 γ 射线照射组的脾肿大发生率≥80%，明显高于 HTLV-1 感染小鼠。由于 γ 射线，脾脏的组织形态变得不均匀。重要的是，与 HTLV-1 感染小鼠相比，HTLV-1 感染和 γ 射线照射小鼠的脾脏中感染细胞数量增加了 4.1 倍。在考虑对 HTLV-1 感染患者进行全身照射时，可能需要谨慎。
