Study On The Phenotypes And Immunological Functions Of Myeloid Derived Suppressor Cells In Breast Cancer Patients

Objective:To investigate if breast cancer patients have MDSC and identify the phenotypes and immunological functions of MDSC in breast cancer patients.To analyze the relevance between the distribution of MDSC and other clinical data.Methods:Paired tumor tissue and blood samples were collected from thirty breast cancer patients,as well as the control blood samples were collected from ten healthy adults.The phenotypes and percentage of MDSC were detected using flowcytometry methods.The tumor-derived MDSC were separated from tumor tissue by magnetic cell sorting system.The cell morphological characteristics were observed by Wright staining.And the inhibitory effects on proliferation of T cell were analyzed using MTT,the cytokine secretion was analyzed using ELISA methods,and the apoptosis was analyzed using flowcytometry.The IDO expression of MDSC was examined by Western blot.The distribution of MDSC in vivo was detected using anti-CD33 by immunohistochemical staining and the relevance of the MDSC distribution and the clinical data was analyzed.Results:A subset of myeloid-derived precursor-like cells was detected both in the tumor tissue and peripheral blood samples of breast cancer patients with phenotypes of linl-CD45+CD13+CD33+CD14'CD15'.The percentage of MDSC in healthy peripheral blood,breast cancer patient peripheral blood and breast tumor tissue is(4.9±4.38)%?(12.92±6.24)%?(17.18±5.19)%.The percentage of MDSC in breast cancer patient peripheral blood and breast tumor tissue is higher than in healthy peripheral blood(P<0.05).The percentage of MDSC in breast cancer patient peripheral blood and breast tumor tissue does not have the significant difference.If IL-2 is 50IU/ml the proliferation of T lymphocytes when incubate with MDSC derived from tumor tissue three days by the percentage of 1:1;1:3;1:6 is(52.34± 4.2)%?56.53±7.1)%?(32.98±12.1)%,If IL-2 is 500IU/ml the proliferation of T lymphocytes when incubate with MDSC derived from tumor tissue three days by the percentage of 1:1;1:3;1:6 is(55.2±7.1)%?(68.4±1.2)%?(64.9±17.1)%.If IL-2 is 500IU/ml the apoptosis when T lymphocytes incubate with MDSC derived from tumor tissue three days by the percentage of 1:1;1:3 is(33.55±10.49)%,(40.65 ± 9.73%Incubate T lymphocytes without MDSC apoptosis percentage is(3.32±3.24)%.It demonstrated that the tumor-derived MDSC inhibited proliferation of IL-2 induced autologous T lymphocytes,and promoted apoptosis of autologous T lymphocytes.If IL-2 is 500IU/ml T lymphocytes incubate with MDSC derived from tumor tissue three days by the percentage of 1:1;1:3,The tumor-derived MDSC inhibited IFN-? secretion dramatically and promote TGF-??IL-10 secretion.IFN-? decrease from(43.19±2.32)ng/ml to(26.95 ±4.55)ng/ml,TGF-? increase from(61.36±6.02)ng/ml to(140.34± 17.11)ng/ml,IL-10 increase from(24.36±3.44)ng/ml to(82.44±5.6)ng/ml.The IDO expression of MDSC was examined by Western blot.The distribution of MDSC in vivo was detected using anti-CD33 by immunohistochemical staining.The nuclei of MDSC were large like kidney and horseshoe,2-4 nucleolus,rich cytoplas.The cells with irregular shape showing myeloid progenitor cell morphology,were distributed in cluster around tumor cells.Clinical date found that the expression of MDSC associated with pathological tumor size(P<0.05),tumor volume is greater the infiltrating MDSC is more,but with age,menopausal status,clinical stage,lymph node metastasis,receptor condition,PCNA and P53 are not related(P>0.05).Conclusion:A distinct subset of MDSC existed in the tumor site of breast cancer patients which committed inhibitory effects of proliferation on autologous T lymphocytes,promote apoptosis of autologous T lymphocytes,and affect cytokine secretion.The marker is linl-CD45+CD13+CD33+CD14-CD15'.The tumor-derived MDSC inhibited IFN-? secretion dramatically and promote TGF-??IL-10 secretion.The IDO expression of MDSC was examined by Western blot.The immunological suppression of MDSC may have the relationship with IDO.MDSC distributed in breast tumor tissue.The Clinical date found that the distribution of MDSC associated with pathological tumor size.Detected the MDSC content may helpful to understand patient 's clinical condition.