CD4+ T-helpers in TCR-dependent tumor immunosurveillance and T-cell based adoptive transfer immunotherapy: are they really that helpful?

Abstract

In this brief review the advances and hurdles of the modern-day ACT (adoptive cell transfer) immunotherapy of cancer are discussed, with the focus on the positive or negative role of CD4+ T helper lymphocytes as one of major constituents of oncologic patient-administered CIK (cytokine-induced killers) lymphocyte culture. The beneficial role of CD4+ T helpers in adoptively-transferred lymphocyte culture is considered, questioned and being put under doubt. “Infectious tolerance” and tumor “immune avoidance” phenomena are described, emphasizing on their dramatic implications for cancer ACT therapy. The ways to circumvent apparent undesired effects of CD4+ T helpers elevated presence in CIK bulk mass are discussed, such as complete removal of CD4 -positive cells, along with a less radical measure, which is depletion of CD4+CD25+FoxP3+ T regulatory lymphocytes from bulk CIK culture.