Polymeric nanoparticles for DNA vaccine-based cancer immunotherapy: a review.

Cancer is one of the leading causes of death and mortality in the world. There is an essential need to develop new drugs or therapeutic approaches to manage treatment-resistant cancers. Cancer immunotherapy is a type of cancer treatment that uses the power of the body's immune system to prevent, control, and eliminate cancer. One of the materials used as a vaccine in immunotherapy is DNA. The application of polymeric nanoparticles as carriers for DNA vaccines could be an effective therapeutic approach to activate immune responses and increase antigen presentation efficiency. Various materials have been used as polymeric nanoparticles, including: chitosan, poly (lactic-co-glycolic acid), Polyethylenimine, dendrimers, polypeptides, and polyesters. Application of these polymer nanoparticles has several advantages, including increased vaccine delivery, enhanced antigen presentation, adjuvant effects, and more sustainable induction of the immune system. Besides many clinical trials and commercial products that were developed based on polymer nanoparticles, there is still a need for more comprehensive studies to increase the DNA vaccine efficiency in cancer immunotherapy using this type of carrier.

Heterologous Prime-boost Vaccination Using Adenovirus and Albumin Nanoparticles as Carriers for Human Papillomavirus 16 E7 Epitope.

BACKGROUND: Nanocarriers are these days considered an attractive approach in cancer immunotherapy owing to their ability to deliver antigens to antigen-presenting cells (APCs) for stimulating robust immune cells against the tumor. OBJECTIVES: The objective of this study was to construct nanocomplexes using two nanocarriers with negative surface charge, adenovirus (Ad) and human serum albumin nanoparticle (HSA-NP), and coat their surface with a modified and positively-charged HPV16 E7 MHC-I specific epitope to assess their anti-tumor effects in a TC-1 mouse model. METHODS: After the construction of Ad and HSA-NP, their complexes with HPV16 E7 MHC-I specific epitope were characterized by zeta potential and dynamic light scattering. Then, the cellular immunity and CTL responses in immunized mice were assessed by measuring the levels of IL-10 and IFN-γ and the expression of CD107a, a marker of CTL response, as well as tumor inhibition. RESULTS: The zeta potential and dynamic light scattering results showed that incubation of the oppositely- charged nanocarriers and MHC-I specific epitope led to the formation of nanocomplexes in which the surface charge of nanocarriers was changed from negative to positive with minimal changes in the particle size. We demonstrated that the nanocomplex platforms in heterologous primeboost regimens generate significantly higher E7-specific IL-10, IFN-γ, and CTL responses. Moreover, the heterologous nanocomplex regimens, Alb/Pep-Ad/Pep and Ad/Pep-Alb/Pep, significantly suppressed the growth of TC-1 tumors in vivo compared with mice receiving homologous regimens and naked nanocarriers. CONCLUSION: The heterologous nanocomplexes might serve as an effective vaccine strategy against HPV-induced cervical cancer.

Virus against virus: strategies for using adenovirus vectors in the treatment of HPV-induced cervical cancer.

Although most human papillomavirus (HPV) infections are harmless, persistent infection with high-risk types of HPV is known to be the leading cause of cervical cancer. Following the infection of the epithelium and integration into the host genome, the oncogenic proteins E6 and E7 disrupt cell cycle control by inducing p53 and retinoblastoma (Rb) degradation. Despite the FDA approval of prophylactic vaccines, there are still issues with cervical cancer treatment; thus, many therapeutic approaches have been developed to date. Due to strong immunogenicity, a high capacity for packaging foreign DNA, safety, and the ability to infect a myriad of cells, adenoviruses have drawn attention of researchers. Adenovirus vectors have been used for different purposes, including as oncolytic agents to kill cancer cells, carrier for RNA interference to block oncoproteins expression, vaccines for eliciting immune responses, especially in cytotoxic T lymphocytes (CTLs), and gene therapy vehicles for restoring p53 and Rb function.