Biological and non biological vectors as vaccine delivery vehicles for cancer therapy

Biological and non biological vectors as vaccine delivery vehicles for cancer therapy
Nazanin Nasehi,^1,*
1. , Department of Cell and Molecular biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan
Introduction: Cancer is one of the leading causes of death that can cause 100 different diseases in different parts of the body, accounting for an estimated 9.6 million deaths, or one in six deaths, in 2018. Between 2007 and 2020, the number of deaths is expected to go up 15.2% in men and 8.1% in women. Cancer begins when changes begin, including the uncontrolled growth of cells. These cells may form a mass called a tumor. Gene therapy has received a lot of attention in the past few decades as an effective treatment for various cancers. Gene therapy relies on the introduction of nucleic acids or their synthetic analogs or genome-modifying proteins into cells to regulate gene expression with minimal off-target effect. A nucleic acid delivery system capable of delivering exogenous genetic material into specific cells. The exogenous genetic material that is delivered into cells by vectors, can be effectively expressed, and the delivery vector itself has low toxicity and does not interfere with the expression of genetic material. Nucleic acid delivery vectors are classified as biological vectors(Efficient transfection and expression but Exiting safety hazard and lacking targeting) and non-biological vectors. Non-biological vectors These vector-like Cationic liposomes are used as DNA delivery agents in gene therapy. Vector molecules form electrostatic interactions with DNA, therewith protects DNA from nucleases and cellular defense mechanisms. however non-viral vectors are safe for gene targeting, its low efficiency compared to viral vectors limits its application in cancer therapy. Research advancements along the years made use of bacterial and viral vectors or the combination of these with synthetic carriers to overcome the drawbacks associated with the use of non-viral vectors alone. Biological vectors (Viral vectors) Viruses are naturally immunogenic and may even stimulate the immune system. Their genetic material can be designed to carry the material we want to express in host cells Bacterial vectors Decreased tumor growth with Streptococcus pyogenes infection has been observed in a cancer patient if bacteria are used. Some bacterial components, like exotoxins, have been reported to initiate antitumor activities by their direct action on tumor cells rather than their indirect effect.
Methods: In Cationic liposomes vectors at physiological pH, the head group of positively charged lipids interacts with the phosphate groups of negatively charged nucleic acids to form a sandwich structure, in which a plurality of liposome particles encloses nucleic acid molecules. Some positively charged complexes are endocytosed or fused with cell membranes by charge to-charge interactions. In endosomal environments, the neutral lipids in cationic liposomes undergo a conformational change that results in the release of complexes into the cytoplasm, thereby avoiding the destruction of nucleic acids by lysosomes. Nucleic acids released into the cytoplasm unlock binding to cationic liposomes at a certain time and enter the nucleus at the time of mitosis to express the genes they carry. Viruses have the ability to infect human cells so they can be used as an effective means of transporting vaccines because they trigger host T cell responses and humoral responses. Oncolytic virus-infected cancer cell process and present viral antigen to their surface, which are recognized by CD4+ and CD8+ T cells, resulted in T cell-mediated cancer cell destruction.
Results: With advances in the human genome project and advances in virology and related sciences, new methods for making non-pathogenic vectors are being developed. The above examples illustrate the different types of vectors commonly used in gene therapy. Each of these biological and non-biological systems has advantages and disadvantages that researchers are trying to use to their advantage. Viral devices are widely used and have a high transmission and expression efficiency, as well as stimulating the immune system and the potential risk of mutations.
Conclusion: New and sophisticated strategies for combating cancer are constantly being presented for gene transfer, as there is no set method for all types of cancer. The development of vectors and effective strategies for transfecting foreign DNA into specific cells is the ultimate goal in gene therapy. The use of recombinant bacteria and viruses is promising, and many researchers are currently working to complete this approach. Virus vectors used as recombinant vaccines activate the immune response of the host tumor through specific T cell immune responses.
Keywords: viral vector, non viral vector, gene therapy, cancer