A Novel Transgenic Zebrafish Line Reporting Dynamic Epigenetic Changes
Currently, there is no other whole-animal reporter for epigenetic regulation established in any vertebrate.
Currently, there is no other whole-animal reporter for epigenetic regulation established in any vertebrate.
The thymus is an integral part of the adaptive immune system as it generates T cells. Its function diminishes rapidly as the body ages, leading to a compromise of the immune system in the elderly. Reconstitution of adaptive immunity through mass production of different T cell types is therefore a therapeutic need in immunocompromised populations. Furthermore, production of T cells with specific receptors targeting cancer cells is an important cancer immunotherapy approach.
Cancer cells can spread to various regions in the body in a process called metastasis which is associated with non-responsive to treatment and thus reduced survival. Identifying the markers of metastasis has been a major concern in the field of cancer diagnosis and therapy. Interestingly, research has shown that there is an increase in myeloid progenitors and myeloid cells at various stages of metastasis in an attempt by the immune system to suppress cancer cells. This presents a promising technology for cancer immunotherapy.
Hematopoietic progenitor cells (HPC) are multi-potent hematopoietic lineage cells that can differentiate into any type of blood cell, including but not limited to erythrocytes, T cells, B cells, and natural killer cells. As such, they have high therapeutic potential in the fields of regenerative medicine and cancer immunotherapy, especially when generated from patient-derived induced pluripotent stem cells (iPSC). Currently, the most efficient protocol to produce HPCs is co-culturing human iPSCs (hiPSC) with mouse stromal cells as a two-dimensional (2D) monolayer.
Many known chemotherapeutic drugs kill abnormal cells through a process called apoptosis. Bcl-2 proteins are negative regulators of apoptosis that control cell survival and death. Increased expression of anti-apoptotic Bcl-2 proteins commonly occurs in up to 30% of all cancers, providing cancer cells a pro-survival advantage to evade cell death, grow, and proliferate. Drugs targeting these specific anti-apoptotic proteins are potential anti-cancer therapeutics.
Cancer cells can upregulate autophagy – cell destruction – as a response to chemotherapy. Investigators in Dr. Melvin DePamphilis’ laboratory at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) have shown that compounds identified by screening a library of compounds blocks autophagy in some cancer cells (e.g., melanoma) but are not toxic to normal cells. Cancer cells with mutations in the BRAF oncogene are especially dependent on autophagy. Treatment of cancer cells with the BRAF mutation can increase the efficacy of chemotherapy.
Targeting the CD22 receptor of B-cells with chimeric antigen receptor (CAR)-T cells has been a promising new therapy to treat B-cell malignancies in clinical trials, inducing remission in 70% of patients with relapsed acute lymphoblastic leukemia (ALL). However, diminished CD22 expression on B-cell surface can lead to relapse and decreased remission duration, which may be prevented through increasing CAR-T affinity towards CD22.
T cell immunotherapy is used in the treatment of various pathologies – including cancers and infections. Current therapies employ chimeric antigen receptors (CARs) consisting of the intracellular fragment of CD3-zeta as the signaling domain with varied combinations of co-stimulatory, transmembrane, spacer/hinge, and extracellular targeting domains. While effective in treating hematological malignancies, CAR T cells need to be activated through T cell receptor (TCR) activation.
Adoptive cell transfer (ACT) and T-cell receptor (TCR) therapies use lymphocytes that target somatic mutations expressed by tumors cells to treat cancer patients. One of the challenges of these therapies is the identification and isolation of mutation-specific cells and TCRs. While neoantigen specific cells are relatively abundant in the tumor, they are far less common in peripheral blood, a more accessible source of T cells.
The treatment of cancer using immunotherapies has garnered substantial attention and excitement considering the clinical benefits observed in patient populations previously refractory to treatment. Tumor infiltrating T cells can significantly impact cancer progression and immunotherapy response; however, immunosuppressive tumor microenvironments can impede antitumor T cell induction, trafficking, and local activity. Thus, personalized immunotherapy approaches have shown limited efficacy against most solid tumors.