Consumption of ß-glucans to spice up T cell treatment of tumors: a review.

ABSTRACT

INTRODUCTION: Adoptive T-cell treatments of solid cancers have evolved into a robust therapy with objective response rates surpassing those of standardized treatments. Unfortunately, only a limited fraction of patients shows durable responses, which is considered to be due to a T cell-suppressive tumor microenvironment (TME). Here we argue that naturally occurring ß-glucans can enable reversion of such T cell suppression by engaging innate immune cells and enhancing numbers and function of lymphocyte effectors. AREAS COVERED This review summarizes timely reports with respect to absorption, trafficking and immune stimulatory effects of ß-glucans, particularly in relation to innate immune cells. Furthermore, we list effects toward well-being and immune functions in healthy subjects as well as cancer patients treated with orally administered ß-glucans, extended with effects of ß-glucan treatments in mouse cancer models. EXPERT OPINION Beta-glucans, when present in food and following uptake in the proximal gut, stimulate immune cells present in gut-associated lymphoid tissue and initiate highly conserved pro-inflammatory pathways. When tested in mouse cancer models, ß-glucans result in better control of tumor growth and shift the TME toward a T cell-sensitive environment. Along these lines, we advocate that intake of ß-glucans provides an accessible and immune-potentiating adjuvant when combined with adoptive T-cell treatments of cancer.