Explore the vast range of titles available.

Leukemia stem cells (LSCs) are resistant to therapy and immune control. The reason for their resistance to elimination by cytotoxic T cells (CTLs) remains unclear. This study shows that specific low abundant Gram-negative intestinal commensals of the genus Sutterella suppress the anti-leukemia immune response in chronic myeloid leukemia (CML). We found that germ-free and specific opportunistic pathogen-free (SOPF) mice are protected from CML development and that colonization of SOPF mice with Sutterella wadsworthensis, but not other related and unrelated bacterial strains, rescues CML development. A higher prevalence of this microbe resulted in Myd88/TRIF-mediated CTL exhaustion in SPF compared to SOPF CML mice as evidenced by higher surface expression of exhaustion markers on CTLs, a reduced capacity to produce interferon-gamma and granzyme B and to kill LSCs in vitro. These findings provide new insights into the immune control of LSCs and identify Sutterella species as regulators of anti-leukemic immunity in CML.