Natural killer cells in tumor immunotherapy

Cancer is the second most common cause of death worldwide and remains one of the critical public health problems of our time1.Recently,immunotherapy has considerably improved the outcomes of patients with advanced cancers.Immune checkpoint blockade and chimeric antigen receptor(CAR)-T cell-based therapies have achieved remarkable success in recent decades,thus placing the host immune response in the spotlight as a potential new approach in antitumor therapy.

Reconstitution of double-negative T cells after cord blood transplantation and its predictive value for acute graft-versus-host disease

Background:With an increasing number of patients with hematological malignancies being treated with umbilical cord blood transplantation(UCBT),the correlation between immune reconstitution(IR)after UCBT and graft-versus-host disease(GVHD)has been reported successively,but reports on double-negative T(DNT)cell reconstitution and its association with acute GVHD(aGVHD)after UCBT are lacking.Methods:A population-based observational study was conducted among 131 patients with hematological malignancies who underwent single-unit UCBT as their first transplant at the Department of Hematology,the First Affiliated Hospital of USTC,between August 2018 and June 2021.IR differences were compared between the patients with and without aGVHD.Results:The absolute number of DNT cells in the healthy Chinese population was 109(70-157)/μL,accounting for 5.82(3.98-8.19)%of lymphocytes.DNT cells showed delayed recovery and could not reach their normal levels even one year after transplantation.Importantly,the absolute number and percentage of DNT cells were significantly higher in UCBT patients without aGVHD than in those with aGVHD within one year(F=4.684,P=0.039 and F=5.583,P=0.026,respectively).In addition,the number of DNT cells in the first month after transplantation decreased significantly with the degree of aGVHD increased,and faster DNT cell reconstitution in the first month after UCBT was an independent protective factor for aGVHD(HR=0.46,95%confidence interval[CI]:0.23-0.93;P=0.031).Conclusions:Compared to the number of DNT cells in Chinese healthy people,the reconstitution of DNT cells in adults with hematological malignancies after UCBT was slow.In addition,the faster reconstitution of DNT cells in the early stage after transplantation was associated with a lower incidence of aGVHD.

Targeting UDP-α-D-glucose 6-dehydrogenase alters the CNS tumor immune microenvironment and inhibits glioblastoma growth

Glioblastoma(GBM,WHO grade IV glioma)is the most common and lethal malignant brain tumor in aduts with a dismal prognosis.The extracellular matrix(ECM)supports GBM progression by promoting tumor cell proliferation,migration,and immune escape.Uridine diphosphate(UDP)-glucose 6-dehydrogenase(UGDH)is the rate-limiting enzyme that catalyzes the biosynthesis of glycosaminoglycans that are the principal component of the CNS ECM.We investigated how targeting UGDH in GBM infuence$the GBM immune microenvironment,including tumor-associated microglia/macrophages(TAMs)and T cells.TAMs are the main im-mune effector cells in GBM and can directly target tumor cells if properly activated.In co-cultures of GBM cells and human primary macrophages,UGDH knockdown in GBM cells pro-moted macrophage phagocytosis and M-like polarization.In orthotropic human GBM xeno-grafts and syngeneic mouse glioma models,targeting UGDH decreased ECM deposition,increased TAM phagocytosis marker expression,reduced M2-like TAMS and inhibited tumor growth.UGDH knockdown in GBM cells also promoted cytotoxic T cell ifltration and activa-tion in orthotopic syngeneic mouse glioma models.The potent and in-human-use small mole-cule GAG synthesis inhibitor 4-methylumbelliferone(4-MU)was found to inhibit GBM cell proliferation and migration in vitro,mimic the macrophage and T-cell responses to UGDH knockdown in vitro and in vivo and inhibit growth of orthotopic murine GBM.Our study shows that UGDH supports GBM growth through multiple mechanisms and supports the development of ECM-based therapeutic strategies to simultaneously target tumor cells and their microenvi-ronment.