Abstract:

Objective To investigate the levels of γδ T cells and their subpopulations in bone marrow（BM）of patients with myelodysplastic syndrome （MDS）， it aims to explore the immune deficiency status of BM microenvironment in MDS patients. Methods BM samples were collected from MDS patients before and after treatment， as well as from normal donors. Multicolor flow cytometry was utilized to detect bone marrow γδ T cells and subpopulation levels. The changes of the T cell subsets after treatment were also analyzed. Results The levels of BM γδ T cells and follicular helper γδ T cells from MDS patients were significantly lower than those of normal donors （P < 0.05）. Among γδ T cells at different stages of differentiation， only the frequencies of na?ve γδ T cells from MDS patients decreased significantly （P = 0.037）， and there was no significant difference observed about central memory， effector memory， and terminally differentiated γδ T cells in MDS patients compared to normal donors （P > 0.05）. Although there was a slight decrease in PD1+γδ T cells and an increase in TIM3+γδ T cells， these differences were not statistically significant （P > 0.05）. In patients who achieved a curative effect， the proportions of γδ T cells and naive γδ T cells increased significantly after treatment， and the effector memory γδ T cells decreased significantly after treatment （P < 0.05）. After treatment， 85.71% （6/7） of MDS patients showed a decrease in γδ+TIM3+ T cell levels to varying degrees. Conclusions The levels of γδ T cells and their subpopulations in the BM microenvironment of patients with MDS exhibit varying degrees of abnormalities. However， in patients who receive effective treatment， these abnormal γδ T cells can recover. By detecting the levels of γδ T cells and subpopulations， we can gain insights into the immune deficiency status of MDS. This information might serve as an indicator to assess treatment efficacy and provide valuable insights for anti?tumor immunotherapy.

Key words: myelodysplastic syndrome, γδ T cells, follicular helper γδ T cells, regulatory γδ T cells, programmed death 1, T cell immunoglobulin and mucin?containing molecule 3