The application of self-assembled nanostructures in peptide-based subunit vaccine development.

Peptide based-vaccines are becoming one of the most widely investigated prophylactic and therapeutic health care interventions against a variety of diseases, including cancer. However, the lack of a safe and highly efficient adjuvant (immune stimulant) is regarded as the biggest obstacle to vaccine development. The incorporation of a peptide antigen in a nanostructure-based delivery system was recently shown to overcome this obstacle. Nanostructures are often formed from antigens conjugated to molecules such as polymers, lipids, and peptide, with the help of self-assembly phenomenon. This review describes the application of self-assembly process for the production of peptide-based vaccine candidates and the ability of these nanostructures to stimulate humoral and cellular immune responses.

Obtention and characterization of the recombinant simian Interleukin-15 in Escherichia coli for the preclinical assessment of an IL-15-based therapeutic vaccine.

Recombinant simian IL-15 (siIL-15) was obtained for the preclinical assessment of an anti-human IL-15 vaccine. For this purpose, the cDNA from peripheral blood mononuclear cells of a Macaca fascicularis monkey was cloned into a pIL-2 vector. The siIL-15 was expressed in Escherichia coli strain W3110 as an insoluble protein which accounted for 13% of the total cellular proteins. Inclusion bodies were solubilized in an 8 M urea solution, which was purified by ion exchange and reverse phase chromatography up to 92% purity. The protein identity was validated by electrospray ionization-mass spectrometry, confirming the presence of the amino acids which distinguish the siIL-15 from human IL-15. The purified siIL-15 stimulates the proliferation of cytotoxic T-lymphocytes line (CTLL)-2 and Kit 225 cells with EC50 values of 3.1 and 32.5 ng/mL, respectively. Antisera from modified human IL-15-immunized macaques were reactive to human and simian IL-15 in enzyme-linked immunosorbent assays. Moreover, the anti-human IL-15 antibodies from immune sera inhibited siIL-15 activity in CTLL-2 and Kit 225 cells, supporting the activity and purity of recombinant siIL-15. These results indicate that the recombinant siIL-15 is biologically active in two IL-15-dependent cell lines, and it is also suitable for the preclinical evaluation of an IL-15-based therapeutic vaccine.

Quantitative T cell repertoire analysis by deep cDNA sequencing of T cell receptor α and ß chains using next-generation sequencing (NGS).

Immune responses play a critical role in various disease conditions including cancer and autoimmune diseases. However, to date, there has not been a rapid, sensitive, comprehensive, and quantitative analysis method to examine T-cell or B-cell immune responses. Here, we report a new approach to characterize T cell receptor (TCR) repertoire by sequencing millions of cDNA of TCR α and ß chains in combination with a newly-developed algorithm. Using samples from lung cancer patients treated with cancer peptide vaccines as a model, we demonstrate that detailed information of the V-(D)-J combination along with complementary determining region 3 (CDR3) sequences can be determined. We identified extensive abnormal splicing of TCR transcripts in lung cancer samples, indicating the dysfunctional splicing machinery in T lymphocytes by prior chemotherapy. In addition, we found three potentially novel TCR exons that have not been described previously in the reference genome. This newly developed TCR NGS platform can be applied to better understand immune responses in many disease areas including immune disorders, allergies, and organ transplantations.