MYC-driven synthesis of Siglec ligands is a glycoimmune checkpoint.

The Siglecs (sialic acid-binding immunoglobulin-like lectins) are glycoimmune checkpoint receptors that suppress immune cell activation upon engagement of cognate sialoglycan ligands. The cellular drivers underlying Siglec ligand production on cancer cells are poorly understood. We find the oncogene causally regulates Siglec ligand production to enable tumor immune evasion.

Reprogramming Cancer into Antigen-Presenting Cells as a Novel Immunotherapy.

Unlabelled: Therapeutic cancer vaccination seeks to elicit activation of tumor-reactive T cells capable of recognizing tumor-associated antigens (TAA) and eradicating malignant cells. Here, we present a cancer vaccination approach utilizing myeloid-lineage reprogramming to directly convert cancer cells into tumor-reprogrammed antigen-presenting cells (TR-APC). Using syngeneic murine leukemia models, we demonstrate that TR-APCs acquire both myeloid phenotype and function, process and present endogenous TAAs, and potently stimulate TAA-specific CD4+ and CD8+ T cells.

Macrophage de novo NAD synthesis specifies immune function in aging and inflammation.

Recent advances highlight a pivotal role for cellular metabolism in programming immune responses. Here, we demonstrate that cell-autonomous generation of nicotinamide adenine dinucleotide (NAD) via the kynurenine pathway (KP) regulates macrophage immune function in aging and inflammation. Isotope tracer studies revealed that macrophage NAD derives substantially from KP metabolism of tryptophan.

Reprogramming of primary human Philadelphia chromosome-positive B cell acute lymphoblastic leukemia cells into nonleukemic macrophages.

BCR-ABL1(+) precursor B-cell acute lymphoblastic leukemia (BCR-ABL1(+) B-ALL) is an aggressive hematopoietic neoplasm characterized by a block in differentiation due in part to the somatic loss of transcription factors required for B-cell development. We hypothesized that overcoming this differentiation block by forcing cells to reprogram to the myeloid lineage would reduce the leukemogenicity of these cells. We found that primary human BCR-ABL1(+) B-ALL cells could be induced to reprogram into macrophage-like cells by exposure to myeloid differentiation-promoting cytokines in vitro or by transient expression of the myeloid transcription factor C/EBPα or PU.

DOCK8 regulates lymphocyte shape integrity for skin antiviral immunity.

DOCK8 mutations result in an inherited combined immunodeficiency characterized by increased susceptibility to skin and other infections. We show that when DOCK8-deficient T and NK cells migrate through confined spaces, they develop cell shape and nuclear deformation abnormalities that do not impair chemotaxis but contribute to a distinct form of catastrophic cell death we term cytothripsis. Such defects arise during lymphocyte migration in collagen-dense tissues when DOCK8, through CDC42 and p21-activated kinase (PAK), is unavailable to coordinate cytoskeletal structures.

Somatic reversion in dedicator of cytokinesis 8 immunodeficiency modulates disease phenotype.

Background: Autosomal recessive loss-of-function mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency characterized by atopy, recurrent infections, and cancer susceptibility. A genotype-phenotype explanation for the variable disease expression is lacking.

Objective: We investigated whether reversions contributed to the variable disease expression.

Genetic, clinical, and laboratory markers for DOCK8 immunodeficiency syndrome.

DOCK8 immunodeficiency syndrome (DIDS) is a combined immunodeficiency characterized by recurrent viral infections, severe atopy, and early onset malignancy. Genetic studies revealed large, unique deletions in patients from different families and ethnic backgrounds. Clinical markers of DIDS include atopic dermatitis, allergies, cutaneous viral infections, recurrent respiratory tract infections, and malignancy.