Peptide-fluorescent bacteria complex as luminescent reagents for cancer diagnosis

Reforming the Chimeric Antigen Receptor by Peptide Towards Optimized CAR T Cells With Enhanced Anti-Cancer Potency and Safety

The emerging chimeric antigen receptor (CAR) T cell revolutionized the clinic treatment of hematological cancers, but meet its Waterloo in solid tumor therapy. Although there exist many reasons for this limitation, one of the largest challenges is the scarcity of recognition for tumor cells, resulting in the undesirable side effects and the subsequent ineffectiveness. To overcome it, a lung-cancer-cell-targeting peptide termed A1 was used in this work to reform the scFv domain of CAR by genetic manipulation. As a result, this modified ^A1CAR T exhibited the optimized cancer-cell targeting and cytotoxicity in vitro and in vivo. More importantly, by tuning the sensitivity of CAR to antigen, peptide-based ^A1CAR T cells could distinguish tumors from normal tissue, thereby eliminating the off-tumor toxicity in healthy organs. Collectively, we herein constructed a genetic peptide-engineered CAR T cells by inserting A1 peptide into the scFv domain. Profitted from the optimized recognition pattern and sensitivity, ^A1CAR T cells showed the ascendancy in solid tumor treatment. Our findings demonstrate that peptide-based CAR T holds great potential in solid tumor therapy due to an excellent targeting ability towards tumor cells.

Cytokine-induced killer cells co-cultured with non-cell derived targeting peptide-loaded dendritic cells induce a specific antitumor response

Cancer is a severe lethal disease. Currently, immunotherapy has become an effective alternative therapeutic approach for cancers. Cytokine-induced killer (CIK) cells have a higher proliferation rate, increased efficacy with few side-effects, and non-MHC-restricted killing after co-culturing with dendritic cells (DCs). Therefore, it has been widely studied and applied in the treatment of cancers. In our study, we explored the antitumor effects of CIK cells co-culturing with DCs pulsed with non-cell derived targeting peptides, which could specifically bind to certain tumor cells. Our results indicated that targeting peptide-loaded DCs could enhance the differentiation and cytotoxicity of CIK cells. Moreover, CIK cells, which were treated with specific targeting peptide-loaded DCs, could effectively and specifically kill tumor cells in vitro and in vivo, as long as tumor cells were pre-coated with the specific binding peptides. In conclusion, targeting peptides could guide DC-CIK to effectively and specifically kill tumor cells which were pre-coated with these targeting peptides and non-cell derived targeting peptide-loaded-DC-CIK may work as a novel means for cancer therapy.

Tumor-targeting peptides from combinatorial libraries

Cancer is one of the major and leading causes of death worldwide. Two of the greatest challenges in fighting cancer are early detection and effective treatments with no or minimum side effects. Widespread use of targeted therapies and molecular imaging in clinics requires high affinity, tumor-specific agents as effective targeting vehicles to deliver therapeutics and imaging probes to the primary or metastatic tumor sites. Combinatorial libraries such as phage-display and one-bead one-compound (OBOC) peptide libraries are powerful approaches in discovering tumor-targeting peptides. This review gives an overview of different combinatorial library technologies that have been used for the discovery of tumor-targeting peptides. Examples of tumor-targeting peptides identified from each combinatorial library method will be discussed. Published tumor-targeting peptide ligands and their applications will also be summarized by the combinatorial library methods and their corresponding binding receptors.