Changes in the natural killer cell repertoire and function induced by the cancer immune adjuvant candidate IMMUNEPOTENT-CRP

Abstract

Natural killer (NK) cells are CD3–, CD16+, CD56+ that play a crucial role in immune response by recognizing and eliminating a variety of virus-infected, malignant, and antibody-coated target cells. We examined activation; repertoire changes and effector functions of human NK cells normal donors treated with IMMUNEPOTENT-CRP (I-CRP), a bovine dialyzable leukocyte extract (DLE) containing a mixture of low molecular weight molecules. I-CRP induces human NK cells activation and increase CD56Dim CD16– subset, without inducing proliferation. Human NK cells showed an increase on NKp30, NKp44, NKp46, NKG2D, NKG2C and KIR receptors, whereas no significant differences on CD160, CD85j and CD226 where observed. I-CRP-treated human NK cells exhibited an increased degranulation activity against K562 target cells, as shown by CD107a assay, and this correlates with cytotoxicity against K562 cells observed in calcein release assay. These results indicate that I-CRP can modify human NK cells receptor repertoire leading to an increased cytotoxic activity, supporting evidence for its use to stimulate NK cells.