Signaling via a CD27-TRAF2-SHP-1 axis during naive T cell activation promotes memory-associated gene regulatory networks

The interaction of the tumor necrosis factor receptor (TNFR) family member CD27 on naive CD8+ T (Tn) cells with homotrimeric CD70 on antigen-presenting cells (APCs) is necessary for T cell memory fate determination. Here, we examined CD27 signaling during Tn cell activation and differentiation. In conjunction with T cell receptor (TCR) stimulation, ligation of CD27 by a synthetic trimeric CD70 ligand triggered CD27 internalization and degradation, suggesting active regulation of this signaling axis. Internalized CD27 recruited the signaling adaptor TRAF2 and the phosphatase SHP-1, thereby modulating TCR and CD28 signals. CD27-mediated modulation of TCR signals promoted transcription factor circuits that induced memory rather than effector associated gene programs, which are induced by CD28 costimulation. CD27-costimulated chimeric antigen receptor (CAR)-engineered T cells exhibited improved tumor control compared with CD28-costimulated CAR-T cells. Thus, CD27 signaling during Tn cell activation promotes memory properties with relevance to T cell immunotherapy.

Synthetic HLA-independent T cell receptors for cancer immunotherapy

CAR T cells are remarkably effective in hematologic malignancies, but tumor cells expressing low antigen levels can escape elimination. In Nature Medicine, Mansilla-Soto et al. design new chimeric receptors that link the variable regions of antibodies directly to T cell receptor chains and recognize tumor cells with improved antigen sensitivity.

Synthetic receptors for logic gated T cell recognition and function

Adoptive cell therapy with T cells engineered with customized receptors that redirect antigen specificity to cancer cells has emerged as an effective therapeutic approach for many malignancies. Toxicity due to on target or off target effects, antigen heterogeneity on cancer cells, and acquired T cell dysfunction have been identified as barriers that can hinder successful therapy. This review will discuss recent advances in T cell engineering that have enabled the application of logic gates in T cells that can mimic the integration of natural signaling pathways and act in a cell intrinsic or extrinsic fashion to precisely target tumor cells and regulate effector functions, potentially overcoming these barriers to effective therapy.

Expression of a TMC6-TMC8-CIB1 heterotrimeric complex in lymphocytes is regulated by each of the components

The TMC genes encode a set of homologous transmembrane proteins whose functions are not well understood. Biallelic mutations in either TMC6 or TMC8 are detected in more than half of cases of the pre-malignant skin disease epidermodysplasia verruciformis (EV). It is controversial whether EV induced by mutations in TMC6 or TMC8 originates from keratinocyte or lymphocyte defects. Quantification of TMC6 and TMC8 RNA levels in various organs revealed that lymphoid tissues have the highest levels of expression of both genes, and custom antibodies confirmed protein expression in mouse lymphocytes. To study the function of these proteins we generated mice with targeted deletion mutant alleles of Tmc6 or Tmc8 Either TMC6 or TMC8 deficiency induced a reduction in apparent molecular weight and/or amount of the other TMC molecule. Co-immunoprecipitation experiments indicated that TMC6 and TMC8 formed a protein complex in mouse and human T cells. MS and biochemical analysis demonstrated that TMC6 and TMC8 additionally interacted with the CIB1 protein to form TMC6-TMC8-CIB1 trimers. We demonstrated that TMC6 and TMC8 regulated CIB1 levels by protecting CIB1 from ubiquitination and proteasomal degradation. Reciprocally, CIB1 was needed for stabilizing TMC6 and TMC8 levels. These results suggest why inactivating mutations in any of the three human genes leads to similar clinical presentations. We also demonstrated that TMC6 and TMC8 levels are drastically lower and the proteins are less active in regulating CIB1 in keratinocytes than in T cells. Our study suggests that defects in lymphocytes may contribute to the etiology and pathogenesis of EV.

Genomics-Driven Immunoproteomics: An Integrative Platform to Uncover Important Biomarkers for Human Diseases

Genomics-driven immunoproteomics (GDI) is a platform that helps identify antigenic protein targets of mutations and other deoxyribonucleic acid (DNA) variations that are commonly associated with pathological states. This platform utilizes data generated from deep sequencing of exomic DNA or ribonucleic acid (RNA) as input to synthesize mutant peptides into microarrays, which then can be used to detect antigenic proteins that invoke immune response in patients. The technology has been used to detect antigenic targets of multiple sclerosis, an autoimmune disease [1], and cancer to identify mutant proteins that invoke immune response in breast cancer patients [2]. This technology has many potential applications to select genomic changes that are specifically recognized by the immune system in a rapid and efficient manner.

Discovery of putative breast cancer antigens using an integrative platform of genomics-driven immunoproteomics

Recent advances in cancer immuno-therapeutics such as checkpoint inhibitors, chimeric antigen-receptor T cells, and tumor infiltrating T cells (TIL) are now significantly impacting cancer patients in a positive manner. Although very promising, reports indicate no more than 25% of cases result in complete remission. One of the limitations of these treatments is the identity of putative cancer antigens in each patient, as it is technically challenging to identify cancer antigens in a rapid fashion. Thus, identification of cancer antigens followed by targeted treatment will increase the efficacy of cancer immunotherapies. To achieve this goal, a combined technologies platform of deep genomic sequencing and personalized immune assessment was devised, termed Genomics Driven Immunoproteomics (GDI). Using this technological platform, we report the discovery of 149 tumor antigens from human breast cancer patients. Significant number of these putative cancer antigens arise from single nucleotide variants (SNVs), as well as insertions and deletions that results into frame-shift mutations. We propose a general model of anti-cancer immunity and suggest that the GDI platform may help identify patient-specific tumor antigens in a timely fashion for precision immunotherapies.