The Role Of Monocytes In The Tumor Microenvironment Of T-cell Lymphoma

BackgroundT cell non-Hodgkin lymphoma(T-NHL)is a type of lymphoma with high invasiveness,large heterogeneity,high mortality and has a higher incidence in Asia.There is no standard treatment regimen nor effective target drugs.Accurate prediction and evaluation of the prognosis of T-NHL helps to select the correct treatment plan to improve the curative effect and survival.Tumor microenvironment and tumor related immunity are hotspots of tumor research.Our research team has previously demonstrated that higher number of tumor associated macrophages(TAM)in tumor tissue is associated with poor prognosis in T-NHL.Monocytes in the peripheral blood are considered the major source of TAM and can be recuited to the tumor tissue by several chemoattractants.What’s more,in a recent pilot study we found for the first time that the lower of CD 16-monocytes/CD 16-monocytes ratio seemed to indicate the worse prognosis of T-NHL.Therefore,the subsets of monocytes in the peripheral blood may play different roles in TAM differenciation and anti-tumor effects.Our study aims to verify the prognostic predictive value of CD16-monocytes/CD16+ monocytes ratio in T-NHL,and to explore the differences between monocyte subsets in order to further understand the mechanisms they involved in tumor microenvironment.It may help clinicians to recognize the high risk patients and provide the individual treatment in future.Objectives1.To verify the prognostic predictive value of peripheral CD 16-monocytes/CD16+monocytes ratio in T-NHL2.To explore the possible relationship between the peripheral monocytes subsets and the tumor associated macrophages3.To investigate the genetic and functional differences of monocyte subsets between T-NHL and the health.MethodsIn this study,31 T-NHL patients without previous treatment in the Peking Union Medical College Hospital from Sep 2015 to May 2017 were enrolled.Blood samples were collected for CD 16-and CD 16+ monocyte count using the flow cytometry(FC500)in conjunction with premixed Cytodiff reagent and analysis software.Follow up was taken regularly and the relationsip between the peripheral CD16-/CD16+ monocyte ratio and the prognosis of T-NHL was analyzed.Multiplexed immunofluorescent staining including CD68 and CD206 and multi-spectral imaging were also performed for the tumor tissues from T-NHL patients without chemotherapy to investigate the correlation between peripheral monocyte subsets and TAMs in the pathological tissue.Furthermore,monocytes subsets from T-NHL patients were sorted by microbeads and flow cytometry to explore the diferent gene expression profiles between the patients and the health so as to reveal the genetic and functional differences and to indicate the molecular mechanism that peripheral monocyte subsets involved in the T-NHL tumor environment.Results1.T-NHL patients had higher ratio of total monocytes especially the CD 16+ monocytes along with a decreased ratio of CD16-/CD16+ monocytes,compared to the health control.The 1-year overall survival rate was 0.492 and 0.755 for CD16-monocyte/CD16+ monocyte ratio of<11 and ≥11,respectively.What’s more,the higher ratio and absolute number of CD 16-monocytes predicted better prognosis,and was better than IPI when combined with IPI to predict the clinical outcome for T-NHL.2.The CD206+ macrophages expressed higher IL10、MMP9 compared to the CD68 macrophages in the NHL pathological tissues.The 1-year survival rate was 0.263 and 0/857 in patients with CD68/CD206 ratio<0.6 and>0.6.Moreover,the CD68/CD206 macrophage ratio was significantly relevant with the peripheral CD 16-/CD 16+monocytes.3.The gene expression of monocyte subsets of the T-NHL patients was significantly different from the health.The differently expressed genes mainly involved in chemokine signaling pathway,cytokine receptor interactions,antigen presentation,cell adhesion moleculars,TNF signaling pathway,complement system,NF-κB pathway and JAK-STAT pathway.Monocyte subsets in T-NHL patients have distinct tumor microenvironment related chemokine,cytokine and adhesion molecular profiles along with abnormal complement system and innate immune system compared with the health.Conclusions 1.T-NHL patients had higher ratio and absolute number of CD 16+ monocytes and a decreased ratio of CD16-/CD16+ monocytes than the health control.Lower ratio of CD 16-/CD16+ monocytes predicted a worse clinical outcome.Combination of CD 16-/CD 16+ monocytes and IPI improved prognosis prediction for T-NHL.2.CD68/CD206 was a good predictor for the prognosis of T-NHL and was was significantly relevant with the peripheral CD16-/CD16+ monocytes.3.The gene expression profiles of monocyte subsets were significantly different between the T-NHL patients and the health.The differentially expressed genes could be related to the tumor immunity and microenvironment in T-NHL.