Soft matter DNA nanoparticles hybridized with CpG motifs and peptide nucleic acids enable immunological treatment of cancer.

Nucleic acids have been used as building blocks to assemble nanostructures by their sequence specific self-recognition properties, and resulting DNA architectures were applied as potential multifunctional drug carriers. Here, we report an amphiphilic lipid-DNA aggregate hybridized with pharmaceutically active DNA and peptide segments for cancer immunotherapy. The facile formulation of the CpG sequence and antigen peptide-bearing peptide nucleic acid representing immune-adjuvant and antigen, respectively, enabled the highly efficacious induction of antigen-specific immune activation. This immunotherapeutic formulation was evaluated in terms of multiple types of tumor growth and metastasis in vivo.

Polyplexes assembled from self-peptides and regulatory nucleic acids blunt toll-like receptor signaling to combat autoimmunity.

Autoimmune diseases occur when the immune system incorrectly recognizes self-molecules as foreign; in the case of multiple sclerosis (MS), myelin is attacked. Intriguingly, new studies reveal toll-like receptors (TLRs), pathways usually involved in generating immune responses against pathogens, play a significant role in driving autoimmune disease in both humans and animal models. We reasoned polyplexes formed from myelin self-antigen and regulatory TLR antagonists might limit TLR signaling during differentiation of myelin-specific T cells, inducing tolerance by biasing T cells away from inflammatory phenotypes. Complexes were formed by modifying myelin peptide with cationic amino acids to create peptides able to condense the anionic nucleic-acid based TLR antagonist. These immunological polyplexes eliminate synthetic polymers commonly used to condense polyplexes and do not rely on gene expression; however, the complexes mimic key features of traditional polyplexes such as tunable loading and co-delivery. Using these materials and classic polyplex analysis techniques, we demonstrate condensation of both immune signals, protection from enzymatic degradation, and tunable physicochemical properties. We show polyplexes reduce TLR signaling, and in primary dendritic cell and T cell co-culture, reduce myelin-driven inflammation. During mouse models of MS, these tolerogenic polyplexes improve the progression, severity, and incidence of disease.

Immunological response to peptide nucleic acid and its peptide conjugate targeted to transactivation response (TAR) region of HIV-1 RNA genome.

Anti-human immunodeficiency virus-1 (HIV-1) polyamide (peptide) nucleic acids (PNAs) conjugated with cell-penetrating peptides (CPPs) targeted to the viral genome are potent virucidal and antiviral agents. Earlier, we have shown that the anti-HIV-1 PNA(TAR)-penetratin conjugate is rapidly taken up by cells and is nontoxic to mice when administered at repeat doses of as high as 100 mg/kg body weight. In the present studies we demonstrate that naked PNA(TAR) is immunologically inert as judged by the proliferation responses of splenocytes and lymph node cells from PNA(TAR)-immunized mice challenged with the immunizing antigen. In contrast, PNA(TAR)-penetratin conjugate is moderately immunogenic mainly due to its penetratin peptide component. Cytokine secretion profiles of the lymph node cells from the conjugate-immunized mice showed marginally elevated levels of proinflammatory cytokines, which are known to promote proliferation of T lymphocytes. Since the candidate compound, PNA(TAR)-penetratin conjugate displays potent virucidal and antiviral activities against HIV-1, the favorable immunological response together with negligible toxicity suggest a strong therapeutic potential for this class of compounds.

The peptide nucleic acid targeted to a regulatory sequence of the translocated c-myc oncogene in Burkitt's lymphoma lacks immunogenicity: follow-up characterization of PNAEmu-NLS.

The present study aims to evaluate the antigenicity of a PNA complementary to the Emu sequence (PNAEmu) with cancer therapeutic potential properties in Burkitt's lymphoma (BL). In BL cells, the c-myc oncogene is repositioned next to the Emu enhancer of the immunoglobulin (Ig) locus, due to chromosomal translocation, and up-regulated. PNAEmu linked to a nuclear localization signal peptide was shown specifically to block c-myc hyperexpression by inhibiting cell growth in vitro and in vivo. Recently, we reported that the administration of PNAEmu to mice, following inoculation with BL cells, hinders tumor growth without toxic effects. To investigate the potential use of PNAEmu in clinical applications further, we tested its antigenicity. Mice were inoculated with an emulsion of free PNA or PNA crosslinked to the immunogenic carrier keyhole limpet hemocyanin (KLH) with Freund's adjuvant. Antibodies to free PNA were undetected, whereas both IgG and IgM antibodies to PNA-KLH were detected in mouse serum 28 and 38 days after inoculation.

[A preliminary study on anti-liver cancer immunity of the virus-like particulate peptide-nucleic acid vaccine].

OBJECTIVES: To construct a novel virus-like particulate peptide-nucleic acid vaccine (VPNV) of human telomerase reverse transcriptase (hTERT), and to study its anti-liver cancer immunity. METHODS: A cationic antigenic peptide was synthesized and purified, and then human granulocyte macrophage colony stimulating factor (hGM-CSF) and TERT gene were cloned into the eukaryotic expression vector pTCAE. The peptide was combined with the nucleic acid vaccine to make a VPNV, which was transfected into eukaryotic cell COS-7. The immunogenicity of hGM-CSF and hTERT were detected using ELISA and Western blot. The efficacy of VPNV for inducing antigen specific CTL response was determined using the lactate dehydrogenase release method. RESULTS: VPNV was verified capable to trigger specific CTL responses and has shown a specific cytolytic activity to liver cancer cell HepG2. CONCLUSION: A VPNV which can stimulate antigen specific CTL response was successfully constructed. This paves the way for our further investigation of anti-liver cancer immunity in mice.