Biological and molecular studies on specific immune cells treated with checkpoint inhibitors for the thera-personal approach of breast cancer patients(ex-vivo study)

Immunotherapy becomes a promising line of treatment for breast cancer(BC)however,its success rate is still limited.Methods:The study was designed to optimize the condition for producing an effective dendritic cell(DCs)based immunotherapy by using DCs and T lymphocytes together with tumor-infiltrating lymphocytes(TILs)and tumor-infiltrating DCs(TIDCs),treated with anti-PD1 and anti-CTLA4 monoclonal antibodies.This mixture of immune cells was co-cultured with autologous breast cancer cells(BCCs)isolated from 26 BC females.Results:There was a significant upregulation of CD86 and CD83 on DCs(p=0.001 and 0.017,respectively),similarly upregulation of CD8,CD4 and CD103 on T cells(p=0.031,0.027,and 0.011,respectively).While there was a significant downregulation of FOXP3 and combined CD25.CD8 expression on regulatory T cells(p=0.014 for both).Increased CD8/Foxp3 ratio(p<0.001)was also observed.CD133,CD34 and CD44 were downregulated on BCCs(p=0.01,0.021,and 0.015,respectively).There was a significant increase in interferon-γ(IFN-γ,p<0.001),lactate dehydrogenase(LDH,p=0.02),and a significant decrease in vascular endothelial growth factor(VEGF,p<0.001)protein levels.Gene expression of FOXP3 and Programmed cell death ligand 1(PDL-1)were downregulated in BCCs(p<0.001,for both),similarly cytotoxic T lymphocyte antigen-4(CTLA4,p=0.02),Programmed cell death 1(PD-1,p<0.001)and FOXP3(p<0.001)were significantly downregulated in T cells.Conclusion:Ex-vivo activation of immune cells(DCs,T cells,TIDCs,and TILs)with immune checkpoint inhibitors could produce a potent and effective BC immunotherapy.However,these data should be validated on an experimental animal model to be transferred to the clinical setting.