Infusion Product TNFα, Th2, and STAT3 Activities Are Associated with Clinical Responses to Transgenic T-cell Receptor Cell Therapy.

Transgenic T-cell receptor (TCR) T cell-based adoptive cell therapies for solid tumors are associated with dramatic initial response rates, but there remain many instances of treatment failure and disease relapse. The association of infusion product cytokine profiles with clinical response has not been explored in the context of TCR T-cell therapy products. Single-cell antigen-dependent secretomic and proteomic analysis of preinfusion clinical TCR T-cell therapy products revealed that TNFα cytokine functionality of CD8+ T cells and phospho-STAT3 signaling in these cells were both associated with superior clinical responsiveness to therapy.

Immunotherapy resistance driven by loss of NY-ESO-1 expression in response to transgenic adoptive cellular therapy with PD-1 blockade.

Background: The tumor antigen NY-ESO-1 has been shown to be an effective target for transgenic adoptive cell therapy (ACT) for the treatment of sarcoma and melanoma. However, despite frequent early clinical responses, many patients ultimately develop progressive disease. Understanding the mechanisms underlying treatment resistance is crucial to improve future ACT protocols.

CD19/CD20 Bispecific Chimeric Antigen Receptor (CAR) in Naive/Memory T Cells for the Treatment of Relapsed or Refractory Non-Hodgkin Lymphoma.

Unlabelled: To address antigen escape and loss of T-cell functionality, we report a phase I clinical trial (NCT04007029) evaluating autologous naive and memory T (TN/MEM) cells engineered to express a bispecific anti-CD19/CD20 chimeric antigen receptor (CAR; CART19/20) for patients with relapsed/refractory non-Hodgkin lymphoma (NHL), with safety as the primary endpoint. Ten patients were treated with 36 × 106 to 165 × 106 CART19/20 cells. No patient experienced neurotoxicity of any grade or over grade 1 cytokine release syndrome.

A Phase I, Open-label, Dose-escalation, and Cohort Expansion Study to Evaluate the Safety and Immune Response to Autologous Dendritic Cells Transduced With AdGMCA9 (DC-AdGMCAIX) in Patients With Metastatic Renal Cell Carcinoma.

Expression of carbonic-anhydrase IX (CAIX) in clear cell renal cell carcinoma (RCC) makes it an attractive vaccine target. We developed a fusion-gene construct, granulocyte-macrophage (GM) colony-stimulating factor+CAIX, delivered by an adenoviral vector (Ad) into autologous dendritic cells (DCs) in this phase 1 study. The injected immature DCs were expected to stimulate an antigen-specific immune response against CAIX expressing RCC.

Epigenetic Suppression of Transgenic T-cell Receptor Expression via Gamma-Retroviral Vector Methylation in Adoptive Cell Transfer Therapy.

Transgenic T-cell receptor (TCR) adoptive cell therapies recognizing tumor antigens are associated with robust initial response rates, but frequent disease relapse. This usually occurs in the setting of poor long-term persistence of cells expressing the transgenic TCR, generated using murine stem cell virus (MSCV) γ-retroviral vectors. Analysis of clinical transgenic adoptive cell therapy products revealed that despite strong persistence of the transgenic TCR DNA sequence over time, its expression was profoundly decreased over time at the RNA and protein levels.

Overcoming Genetically Based Resistance Mechanisms to PD-1 Blockade.

Mechanism-based strategies to overcome resistance to PD-1 blockade therapy are urgently needed. We developed genetic acquired resistant models of , and loss-of-function mutations by gene knockout in human and murine cell lines. Human melanoma cell lines with knockout became insensitive to IFN-induced antitumor effects, while knockout was no longer recognized by antigen-specific T cells and hence was resistant to cytotoxicity.

PAK4 inhibition improves PD-1 blockade immunotherapy.

Lack of tumor infiltration by immune cells is the main mechanism of primary resistance to programmed cell death protein 1 (PD-1) blockade therapies for cancer. It has been postulated that cancer cell-intrinsic mechanisms may actively exclude T cells from tumors, suggesting that the finding of actionable molecules that could be inhibited to increase T cell infiltration may synergize with checkpoint inhibitor immunotherapy. Here, we show that p21-activated kinase 4 (PAK4) is enriched in non-responding tumor biopsies with low T cell and dendritic cell infiltration.

Development of Hematopoietic Stem Cell-Engineered Invariant Natural Killer T Cell Therapy for Cancer.

Invariant natural killer T (iNKT) cells are potent immune cells for targeting cancer; however, their clinical application has been hindered by their low numbers in cancer patients. Here, we developed a proof-of-concept for hematopoietic stem cell-engineered iNKT (HSC-iNKT) cell therapy with the potential to provide therapeutic levels of iNKT cells for a patient's lifetime. Using a human HSC engrafted mouse model and a human iNKT TCR gene engineering approach, we demonstrated the efficient and long-term generation of HSC-iNKT cells in vivo.

A Pilot Trial of the Combination of Transgenic NY-ESO-1-reactive Adoptive Cellular Therapy with Dendritic Cell Vaccination with or without Ipilimumab.

Purpose: Transgenic adoptive cell therapy (ACT) targeting the tumor antigen NY-ESO-1 can be effective for the treatment of sarcoma and melanoma. Preclinical models have shown that this therapy can be improved with the addition of dendritic cell (DC) vaccination and immune checkpoint blockade. We studied the safety, feasibility, and antitumor efficacy of transgenic ACT with DC vaccination, with and without CTLA-4 blockade with ipilimumab.

Immunotherapy Resistance by Inflammation-Induced Dedifferentiation.

A promising arsenal of targeted and immunotherapy treatments for metastatic melanoma has emerged over the last decade. With these therapies, we now face new mechanisms of tumor-acquired resistance. We report here a patient whose metastatic melanoma underwent dedifferentiation as a resistance mechanism to adoptive T-cell transfer therapy (ACT) to the MART1 antigen, a phenomenon that had been observed only in mouse studies to date.

Characterization of Postinfusion Phenotypic Differences in Fresh Versus Cryopreserved TCR Engineered Adoptive Cell Therapy Products.

Adoptive cell therapy (ACT) consisting of genetically engineered T cells expressing tumor antigen-specific T-cell receptors displays robust initial antitumor activity, followed by loss of T-cell activity/persistence and frequent disease relapse. We characterized baseline and longitudinal T-cell phenotype variations resulting from different manufacturing and administration protocols in patients who received ACT. Patients with melanoma who enrolled in the F5-MART-1 clinical trial (NCT00910650) received infusions of MART-1 T-cell receptors transgenic T cells with MART-1 peptide-pulsed dendritic cell vaccination.

Primary Resistance to PD-1 Blockade Mediated by JAK1/2 Mutations.

Unlabelled: Loss-of-function mutations in JAK1/2 can lead to acquired resistance to anti-programmed death protein 1 (PD-1) therapy. We reasoned that they may also be involved in primary resistance to anti-PD-1 therapy. JAK1/2-inactivating mutations were noted in tumor biopsies of 1 of 23 patients with melanoma and in 1 of 16 patients with mismatch repair-deficient colon cancer treated with PD-1 blockade.

Distinct Genetic Networks Orchestrate the Emergence of Specific Waves of Fetal and Adult B-1 and B-2 Development.

B cell development is often depicted as a linear process initiating in the fetus and continuing postnatally. Using a PU.1 hypomorphic mouse model, we found that B-1 and B-2 lymphopoiesis occurred in distinct fetal and adult waves differentially dependent on the Sfpi1 14 kB upstream regulatory element.

Mutations Associated with Acquired Resistance to PD-1 Blockade in Melanoma.

Background: Approximately 75% of objective responses to anti-programmed death 1 (PD-1) therapy in patients with melanoma are durable, lasting for years, but delayed relapses have been noted long after initial objective tumor regression despite continuous therapy. Mechanisms of immune escape in this context are unknown.

Methods: We analyzed biopsy samples from paired baseline and relapsing lesions in four patients with metastatic melanoma who had had an initial objective tumor regression in response to anti-PD-1 therapy (pembrolizumab) followed by disease progression months to years later.

The expansion of thymopoiesis in neonatal mice is dependent on expression of high mobility group a 2 protein (Hmga2).

Cell number in the mouse thymus increases steadily during the first two weeks after birth. It then plateaus and begins to decline by seven weeks after birth. The factors governing these dramatic changes in cell production are not well understood.

Proteolytic histone modification by mast cell tryptase, a serglycin proteoglycan-dependent secretory granule protease.

A hallmark feature of mast cells is their high content of cytoplasmic secretory granules filled with various preformed compounds, including proteases of tryptase-, chymase-, and carboxypeptidase A3 type that are electrostatically bound to serglycin proteoglycan. Apart from participating in extracellular processes, serglycin proteoglycan and one of its associated proteases, tryptase, are known to regulate cell death by promoting apoptosis over necrosis. Here we sought to outline the underlying mechanism and identify core histones as primary proteolytic targets for the serglycin-tryptase axis.

Causes, consequences, and reversal of immune system aging.

The effects of aging on the immune system are manifest at multiple levels that include reduced production of B and T cells in bone marrow and thymus and diminished function of mature lymphocytes in secondary lymphoid tissues. As a result, elderly individuals do not respond to immune challenge as robustly as the young. An important goal of aging research is to define the cellular changes that occur in the immune system and the molecular events that underlie them.

Genetic regulation of thymocyte progenitor aging.

The number of T cell progenitors is significantly reduced in the involuted thymus, and the growth and developmental potential of the few cells that are present is severely attenuated. This review provides an overview of how aging affects T cell precursors before and following entry into the thymus and discusses the age-related genetic changes that may occur in them. Finally, interventions that rejuvenate thymopoiesis in the elderly by targeting T cell progenitors are discussed.

Fibroblast growth factor-7 partially reverses murine thymocyte progenitor aging by repression of Ink4a.

Involution of the thymus results in reduced production of naive T cells, and this in turn is thought to contribute to impaired immunity in the elderly. Early T-cell progenitors (ETPs), the most immature intrathymic T-cell precursors, harvested from the involuted thymus exhibit a diminished proliferative potential and increased rate of apoptosis and as a result their number is significantly reduced. In the present study, we show that these age-induced alterations result in part from increased expression of the Ink4a tumor-suppressor gene in ETPs.

Influence of FAS on murine mast cell maturation.

Background: FAS has been shown to be involved in the regulation of many immune processes by induction of cellular apoptosis. However, accumulated evidence shows that FAS signaling also exhibits nonapoptotic functions, such as induction of cell proliferation and differentiation. FAS is the only death receptor known to be expressed on murine mast cells (MCs).

Human mast cells express intracellular TRAIL.

Recently we demonstrated that human mast cells (MC) express functional TRAIL death receptors. Here we assessed the expression of TRAIL on both mRNA and protein level in cord blood derived MC (CBMC) and HMC-1. The TRAIL release either spontaneous or induced by LPS, IFN-gamma and IgE-dependent activation, was evaluated as well.