Live-Attenuated Bacterial Vectors for Delivery of Mucosal Vaccines, DNA Vaccines, and Cancer Immunotherapy

Abstract

Vaccines save millions of lives each year from various life-threatening infectious diseases, and there are more than 20 vaccines currently licensed for human use worldwide. Moreover, in recent decades immunotherapy has become the mainstream therapy, which highlights the tremendous potential of immune response mediators, including vaccines for prevention and treatment of various forms of cancer. However, despite the tremendous advances in microbiology and immunology, there are several vaccine preventable diseases which still lack effective vaccines. Classically, weakened forms (attenuated) of pathogenic microbes were used as vaccines. Although the attenuated microbes induce effective immune response, a significant risk of reversion to pathogenic forms remains. While in the twenty-first

Personalized Immunotherapy in Colorectal Cancers: Where Do We Stand?

“…Viral, bacterial, and yeast vectors can also be loaded with genes encoding neoantigens and induce robust immune responses against the tumor (44). These vectors release pathogen-associated molecular patterns (PAMPs) that stimulate the innate and adaptive immune response and increase the infiltration of immune cells into the tumor site (206)(207)(208)(209)(210). Adenoviruses, lentiviruses, retroviruses, and Poxviruses are important viral vectors in vaccine design (211).…”

Specific Cell Targeting by Toxoplasma gondii Displaying Functional Single-Chain Variable Fragment as a Novel Strategy; A Proof of Principle

“…Moreover, advances in genetic engineering have allowed the application of several strategies to enhance oncolysis and immune stimulation or to counteract the tumor neovascularization [ 12 , 13 ]. Additionally, several attenuated viruses and bacteria strains have been generated and widely investigated as vaccine vectors to elicit tumor antigen-specific CD8+ T-cell responses and induce protective immunity against tumor development [ 14 , 15 ]. In 2015, the U.S Food and Drug Administration (FDA) approved the use of the recombinant attenuated herpes simplex virus encoding human granulocyte macrophage colony-stimulating factor (GM-CSF) for treatment of melanoma patients with injectable but non-resectable lesions in the skin and lymph nodes [ 16 ].…”