The gut microbiota protein BOC1 exhibits immune checkpoint inhibitor-like activity by inhibiting myeloid-derived suppressor cell differentiation

The immunostimulatory properties of BOC1 observed <i>in vitro</i> are compatible with an ICI-like behavior of this bacterial protein. Given that neither the CD200 protein nor the anti-CD200 antibody is able to compete with BOC1 for binding to CD200R1, and as supported by AlphaFold modeling predictions, CD200 and BOC1 might target different regions of CD200R1.