Fig. 1

Graphic representation of anti-cancer immune response in HER2+ breast cancer. The anti-cancer immune response is composed by two phases: in the first phase (early phase), DCs sample, process, and present TAAs (such as HER2) generating T cell triggering (both CD4 and CD8) with consequent specific antibody production and cytotoxic cell activation. The process involved in the first phase is responsible for the development of vaccines. The second phase takes place in peripheral areas where specific anti-HER2 antibodies and activated cytotoxic cells explicit their functions. The second phase is the main target of other anti-tumor drugs such as anti-HER2 antibody, antibody-drug conjugate, tyrosine kinase inhibitors, or immune checkpoint inhibitors. Legend: Ab-HER2= anti-HER2 antibody; APC= antigen-presenting cell; B7= B7 protein; CD28= T cell costimulatory molecule CD28; CTLA-4= cytotoxic T-lymphocyte–associated antigen 4; DC= dendritic cell; HER2= human epidermal growth factor 2; MHC= major histocompatibility complex; PD-1= Programmed cell death protein 1; PDL-1= Programmed death-ligand 1; TAAs= tumor-associated antigens; TCR= T-cell receptor; Tregs= regulatory T cells; T CD8= CD8+ cytotoxic T cell; T CD4=CD4+ T cell