Immune checkpoint therapy-elicited sialylation of IgG antibodies impairs antitumorigenic type I interferon responses in hepatocellular carcinoma

The reinvigoration of anti-tumor T cells in response to immune checkpoint blockade (ICB) therapy is well established. Whether and how ICB therapy manipulates antibody-mediated immune response in cancer environments, however, remains elusive. Using tandem mass spectrometric analysis of modification of immunoglobulin G (IgG) from hepatoma tissues, we identified a role of ICB therapy in catalyzing IgG sialylation in the Fc region. Effector T cells triggered sialylation of IgG via an interferon (IFN)-γ-ST6Gal-I-dependent pathway. DC-SIGN⁺ macrophages represented the main target cells of sialylated IgG. Upon interacting with sialylated IgG, DC-SIGN stimulated Raf-1-elicited elevation of ATF3, which inactivated cGAS-STING pathway and eliminated subsequent type-I-IFN-triggered antitumorigenic immunity. Although enhanced IgG sialylation in tumors predicted improved therapeutic outcomes for patients receiving ICB therapy, impeding IgG sialylation augmented antitumorigenic T cell immunity after ICB therapy. Thus, targeting antibody-based negative feedback action of ICB therapy has potential for improving efficacy of cancer immunotherapies.

Targeting inflammatory macrophages rebuilds therapeutic efficacy of DOT1L inhibition in hepatocellular carcinoma

Epigenetic reprogramming is a promising therapeutic strategy for aggressive cancers, but its limitations in vivo remain unclear. Here, we showed, in detailed studies of data regarding 410 patients with human hepatocellular carcinoma (HCC), that increased histone methyltransferase DOT1L triggered epithelial-mesenchymal transition-mediated metastasis and served as a therapeutic target for human HCC. Unexpectedly, although targeting DOT1L in vitro abrogated the invasive potential of hepatoma cells, abrogation of DOT1L signals hardly affected the metastasis of hepatoma in vivo. Macrophages, which constitute the major cellular component of the stroma, abrogated the anti-metastatic effect of DOT1L targeting. Mechanistically, NF-κB signal elicited by macrophage inflammatory response operated via a non-epigenetic machinery to eliminate the therapeutic efficacy of DOT1L targeting. Importantly, therapeutic strategy combining DOT1L-targeted therapy with macrophage depletion or NF-κB inhibition in vivo effectively and successfully elicited cancer regression. Moreover, we found that the densities of macrophages in HCC determined malignant cell DOT1L-associated clinical outcome of the patients. Our results provide insight into the crosstalk between epigenetic reprogramming and cancer microenvironments and suggest that strategies to influence the functional activities of inflammatory cells may benefit epigenetic reprogramming therapy.

[Research of the relation between the type of asthenia of the spleen and kidney and platelet associated antibodies and T-lymphocyte subsets in idiopathic thrombocytopenic purpura]

Idiopathic thrombocytopenic purpura (ITP) is a kind of disease associated with immunity. At present a great quantity of study on ITP has been made on humoral and cellular immunity. But there are few reports about the relationship between the types based on the differential diagnosis of TCM and immune rationale of ITP. In order to deeply explore the relationship between the types based on differential diagnosis of TCM and immune rationale of ITP., the authors measured PAIg and T lymphocyte subsets of 34 ITP patients of asthenia of both Spleen and Kidney. The value of PAIgG increased in both types of Spleen failing to control blood (SFCB) and deficiency of Spleen-yin and Kidney -yin (DSYKY), and the value of PAIgG of the type of DSYKY was significantly higher than that of SFCB (P less than 0.01). OKT3, OKT4/OKT8 of the type of SFCB remarkably decreased (P less than 0.05), OKT4, OKT4/OKT8 of DSYKY also remarkably decreased (P less than 0.001), while OKT8 significantly increased (P less than 0.001). The above results suggested that the type of DSYKY has more serious immune dysfunction than the type of SFCB, and the types of SFCB and DSYKY has close relationship with PAIg T lymphocyte subsets.