Among all the current cancers identified, blood borne cancers have presented unique therapeutic challenges. Since the discovery of leukemias in 1847 by Rudolf Virchow , researchers have been attempting to treat blood cancers using a multitude of different strategies such as chemotherapy and kinase inhibitors . There are three types of blood cancers with several subtypes; (1) Leukemia, a blood cancer which is characterized by abnormal white blood cells that accumulate in the blood and bone marrow , (2) Lymphoma, a cancer of lymphocyte cells that are normally a large part of the immune system , and (3) Myeloma, a cancer of plasma cells that produces antibodies as part of the immune system . Some types of blood cancers such as leukemia currently have several treatment options, however, most of these therapeutics are limited in scope, and may not prevent disease reoccurrence . As our understanding of blood cancers has increased, the genetic analysis and identification of driver oncogenes  have provided alternative therapeutic methods to deal with blood cancers, such as immunotherapies coupled with RNAi. Recently, researchers have moved towards the use of immunotherapies to treat blood cancers and this approach has been studied extensively to maximize its efficiency in blood cancers and adopt it for other diseases.
Immunotherapies that involve genetic engineering of host cells are focussed on the cells of the immune system, such as T-cells, B-cells, Natural Killer (NK) cells and others . The use of T-cells has become the accepted ‘norm’ in immunotherapeutic treatments. T-cells engineered for binding to specific cancer antigens interacts with target cells to initiate the overall immune response via the T-cell receptors . Chimeric Antigen Receptor (CAR) T-cells, that target tumor antigens and activate the intracellular pathways for immune response, have been generated primarily by viral gene transfer, although other technologies such as CRISPR-Cas9 are currently been used in clinical trials . There are several challenges with this technology; the delivery of nucleic acids to engineer the immune cell must occur in a way that is efficient, non-toxic, and provides short turn around . This of course does not address other issues such as cytokine release syndrome and others . Despite these challenges, CAR T-cells have shown great potential in ex vivo and in vivo models when using nanotechnologies as they drastically improve deployment of immune cell engineering for blood cancer treatments . Their approval by the US Food and Drug Administration (FDA) has further propelled the technology to everyday use in a clinical setting.
Blood cancers that are derived from suspension-growing cells, with inherently low levels of endocytosis, are notorious for being hard to transfect for engineering purposes, which adds another level of complexity to immune cell-based therapies. The tailoring of reagents to specific cell types and nucleic acid cargos provides a better change at delivery as opposed to finding a universal transfection system. This not only applies to blood cancers like leukemia but to other cancer targets as well. Key steps undertaken by RJH Biosciences show the great potential of lipopolymeric entities for clinical applications. Previous research has shown delivery of nucleic acids with the use of this class of novel transfection reagents [11,12,13]. With a focus on siRNA entities to employ RNAi technology, silencing of tumour associated proteins such as CD44, CXCR4, SDF-1, and BCR-abl has been possible. Our reagents have been additionally developed for the delivery of both mRNA and pDNA, therefore covering a multitude of different experimental methods. But the question is, can technologies such as RJH transfection reagents and siRNA be used in immunotherapy?
The answer is yes! CAR T-cell therapy is a new type of gene therapy approved by the FDA and was designed for B-cell lymphoma . In order to improve T-cell immunotherapies, siRNAs have been delivered into CAR T-cells to downregulate proteins such as Programmed cell death protein 1 (PD-1) and T lymphocyte-associated protein 4 (CTLA-4), which prevent the expression of inhibitory receptors and enhance the CAR T-cell effectiveness against tumours.  As siRNA can also be delivered in vivo using nanoparticle technologies, regulation of genes in the human and animal models can be conducted . Downregulation strategies such as the use of siRNA are only starting to be used in early-stage clinical trials. For example, Celyad Oncology recently announced their clinical trial for shRNA CAR T-cell therapy for multiple myeloma . Although still in its infancy, the use of RNAi type methods in immunotherapies is gaining momentum and likely to bolster the efficacy of CAR-T based interventions.
Delivery of nucleic acids into immune cells is commonly undertaken using adenoviruses, adenovirus-associated viruses (AAV) or lentivirus vectors. These methods however insert the therapeutic DNA into random regions of the genome, which can disrupt essential gene expression. Another method is using DNA nucleofection/electroporation, but this approach has a high cytotoxicity on cells and it is a difficult protocol to scale-up. The use of effective delivery vehicles such as RJH lipopolymers can improve the engineering process, prevent issues such as cytotoxicity, and streamline immunotherapy production. Our transfection reagents are incredibly effective at transfecting suspension cells. Taking our customers or our own siRNA projects, we can effectively deliver polynucleotides into immune cells and other blood cell types, supporting the development and advancement of immunotherapies for blood cancers. Due to our expertise in RNAi, nucleic acid delivery, and blood cancer-based research, producing multiple immunotherapy treatment options is possible. As many immunotherapies rely on the delivery of pDNA or RNA, RJH has focused on tailoring the delivery of the polynucleotides. Our website contains a list of testimonials that show the various applications we and others have done with our transfection reagents. We would also like to highlight two of our application notes that indicate the success we have had with delivering mRNA and micro-RNA in suspension based cells associated with hematologic diseases.