Targeting human plasma cells using small molecule regulated BCMA CAR T cells eliminates circulating antibodies in humanized mice.

Pathogenic long-lived plasma cells (LLPCs) secrete autoreactive antibodies, exacerbating autoimmune diseases and complicating solid organ transplantation. Targeted elimination of the autoreactive B-cell pool represents a promising therapeutic strategy, yet current treatment modalities fall short in depleting mature plasma cells. Here, we demonstrate that chimeric antigen receptor (CAR) T cells, targeting BCMA utilizing a split-receptor design, offer a controlled and effective therapeutic strategy against LLPCs.

Generation, expansion, gene delivery, and single-cell profiling in rhesus macaque plasma B cells.

A key step in developing engineered B cells for therapeutic purposes is evaluation in immunocompetent, large-animal models. Therefore, we developed methods to purify, expand, and differentiate non-human primate (NHP; rhesus macaque) B cells. After 7 days in culture, B cells expanded 10-fold, differentiated into a plasma cell phenotype (CD38, CD138), and secreted immunoglobulin G.

Efficient and sustained locus editing in hematopoietic stem cells as a therapeutic approach for IPEX syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a monogenic disorder caused by mutations in the gene, required for generation of regulatory T (T) cells. Loss of T cells leads to immune dysregulation characterized by multi-organ autoimmunity and early mortality. Hematopoietic stem cell (HSC) transplantation can be curative, but success is limited by autoimmune complications, donor availability and/or graft-vs.

Pancreatic islet-specific engineered T exhibit robust antigen-specific and bystander immune suppression in type 1 diabetes models.

Adoptive transfer of regulatory T cells (T) is therapeutic in type 1 diabetes (T1D) mouse models. T that are specific for pancreatic islets are more potent than polyclonal T in preventing disease. However, the frequency of antigen-specific natural T is extremely low, and ex vivo expansion may destabilize T, leading to an effector phenotype.

Gene editing to induce FOXP3 expression in human CD4 T cells leads to a stable regulatory phenotype and function.

Thymic regulatory T cells (tT) are potent inhibitors of autoreactive immune responses, and loss of tT function results in fatal autoimmune disease. Defects in tT number or function are also implicated in multiple autoimmune diseases, leading to growing interest in use of T as cell therapies to establish immune tolerance. Because tT are present at low numbers in circulating blood and may be challenging to purify and expand and also inherently defective in some subjects, we designed an alternative strategy to create autologous T-like cells from bulk CD4 T cells.

Homology-Directed Recombination for Enhanced Engineering of Chimeric Antigen Receptor T Cells.

Gene editing by homology-directed recombination (HDR) can be used to couple delivery of a therapeutic gene cassette with targeted genomic modifications to generate engineered human T cells with clinically useful profiles. Here, we explore the functionality of therapeutic cassettes delivered by these means and test the flexibility of this approach to clinically relevant alleles. Because CCR5-negative T cells are resistant to HIV-1 infection, CCR5-negative anti-CD19 chimeric antigen receptor (CAR) T cells could be used to treat patients with HIV-associated B cell malignancies.

αE-catenin inhibits a Src-YAP1 oncogenic module that couples tyrosine kinases and the effector of Hippo signaling pathway.

Cell-cell adhesion protein αE-catenin inhibits skin squamous cell carcinoma (SCC) development; however, the mechanisms responsible for this function are not completely understood. We report here that αE-catenin inhibits β4 integrin-mediated activation of SRC tyrosine kinase.SRCis the first discovered oncogene, but the protein substrate critical for SRC-mediated transformation has not been identified.

Flap Endonuclease 1 Limits Telomere Fragility on the Leading Strand.

The existence of redundant replication and repair systems that ensure genome stability underscores the importance of faithful DNA replication. Nowhere is this complexity more evident than in challenging DNA templates, including highly repetitive or transcribed sequences. Here, we demonstrate that flap endonuclease 1 (FEN1), a canonical lagging strand DNA replication protein, is required for normal, complete leading strand replication at telomeres.

14-3-3 proteins restrain the Exo1 nuclease to prevent overresection.

The DNA end resection process dictates the cellular response to DNA double strand break damage and is essential for genome maintenance. Although insufficient DNA resection hinders homology-directed repair and ATR (ataxia telangiectasia and Rad3 related)-dependent checkpoint activation, overresection produces excessive single-stranded DNA that could lead to genomic instability. However, the mechanisms controlling DNA end resection are poorly understood.

Okazaki fragment processing-independent role for human Dna2 enzyme during DNA replication.

Dna2 is an essential helicase/nuclease that is postulated to cleave long DNA flaps that escape FEN1 activity during Okazaki fragment (OF) maturation in yeast. We previously demonstrated that the human Dna2 orthologue (hDna2) localizes to the nucleus and contributes to genomic stability. Here we investigated the role hDna2 plays in DNA replication.

GSK-3 beta targets Cdc25A for ubiquitin-mediated proteolysis, and GSK-3 beta inactivation correlates with Cdc25A overproduction in human cancers.

The Cdc25A phosphatase positively regulates cell-cycle transitions, is degraded by the proteosome throughout interphase and in response to stress, and is overproduced in human cancers. The kinases targeting Cdc25A for proteolysis during early cell-cycle phases have not been identified, and mechanistic insight into the cause of Cdc25A overproduction in human cancers is lacking. Here, we demonstrate that glycogen synthase kinase-3beta (GSK-3beta) phosphorylates Cdc25A to promote its proteolysis in early cell-cycle phases.