High-Dimensional mass cytometry analysis reveals systemic immune perturbations in paediatric cancer influenced by age

Systemic immunity plays an important role in cancer immune surveillance and therapy but there is little detailed knowledge about the immune status of healthy children or children with cancer. We performed a high dimensional single cell analysis of systemic immunity in pediatric cancer patients and age-matched healthy children. In young children with cancer (age < 8years) NK cells were decreased in frequency, maturity, expression of perforin and granzyme-B, and were less cytotoxic in ex vivo assays. NK cell activity was restored after in vitro culture with interleukin-2. In contrast, older children with cancer (>8 years old) had decreased naive CD4 and CD8 T-cells with concomitant increases in effector memory and T effector memory RA-revertant (TEMRA) T-cells. These immunological changes in pediatric cancer patients are relevant to the better understanding of how cancers diagnosed in childhood interact with systemic immunity and could inform the development and application of effective immune-modulating therapies in the pediatric population. One Sentence SummaryHigh dimensional analysis of systemic immunity in pediatric cancer patients reveals clinically relevant immune changes in NK and T-cells that vary with patient age.