Immunosignature system for diagnosis of cancer

Identification of characteristic TRB V usage in HBV-associated HCC by using differential expression profiling analysis

Liver cancer is one of the most common cancers worldwide. CDR3 sequencing-based immune repertoire can be closely associated with cancer prognosis and development. Identifying the specific interaction between the TCR and cellular antigens is important for developing novel immunotherapeutic approaches for the treatment of cancer. The rearranged TCRβ loci amplified using Vβ- and Jβ-specific primers by multi-PCR and sequenced using high-throughput sequencing (HTS) in liver cancers were compared with those of T cells from healthy adult peripheral blood and from adjacent liver tissue. The T-cell repertoires within each tumor show strong similarity to one another but are distinct from those of the circulating T-cell repertoire. In addition, our results demonstrate that there are significant differences in the T-cell repertoires of HCC (hepatocellular carcinoma), ICC (intrahepatic cholangiocarcinoma), and MHC (mixed hepatocellular and cholangiocellular carcinoma). Furthermore, we found that the highly expanded clone (HEC) ratio in blood samples from liver cancer patients differed significantly from those in the blood of healthy adults and hepatitis patients (p < 0.001). The above results suggest that comparison of the T-cell repertoires of tissue and blood could be used to distinguish liver cancer patients from healthy adults and from hepatitis patients. In the future, the diversity of CDR3 sequences in liver cancer may prove to be a useful and novel biomarker for detecting aggressive tumors with high invasive or metastatic capacity.

Author's view: radiation and immunotherapy as systemic therapy for solid tumors

The ability of tumors to evade detection by the immune system via inducing immunosuppression prompted the therapeutic development of immune checkpoint inhibitors. In our recent review, we discussed findings from preclinical and clinical investigations of these agents utilized in combination with radiation inducing abscopal (systemic) antitumor effects.

Epitope identification from fixed-complexity random-sequence peptide microarrays

Antibodies play an important role in modern science and medicine. They are essential in many biological assays and have emerged as an important class of therapeutics. Unfortunately, current methods for mapping antibody epitopes require costly synthesis or enrichment steps, and no low-cost universal platform exists. In order to address this, we tested a random-sequence peptide microarray consisting of over 330,000 unique peptide sequences sampling 83% of all possible tetramers and 27% of pentamers. It is a single, unbiased platform that can be used in many different types of tests, it does not rely on informatic selection of peptides for a particular proteome, and it does not require iterative rounds of selection. In order to optimize the platform, we developed an algorithm that considers the significance of k-length peptide subsequences (k-mers) within selected peptides that come from the microarray. We tested eight monoclonal antibodies and seven infectious disease cohorts. The method correctly identified five of the eight monoclonal epitopes and identified both reported and unreported epitope candidates in the infectious disease cohorts. This algorithm could greatly enhance the utility of random-sequence peptide microarrays by enabling rapid epitope mapping and antigen identification.

Universal screening test based on analysis of circulating organ-enriched microRNAs: a novel approach to diagnostic screening

Early disease detection leads to more effective and cost-efficient treatment. It is especially important for cancer and neurodegenerative diseases, because progression of these pathologies leads to significant and frequently irreversible changes in underlying pathophysiological processes. At the same time, the development of specific screening tests for detection of each of the hundreds of human pathologies in asymptomatic stage may be impractical. Here, we discuss a recently proposed concept: the development of minimally invasive Universal Screening Test (UST) based on analysis of organ-enriched microRNAs in plasma and other bodily fluids. The UST is designed to detect the presence of a pathology in particular organ systems, organs, tissues or cell types without diagnosing a specific disease. Once the pathology is detected, more specific, and if necessary invasive and expensive, tests can be administered to precisely define the nature of the disease. Here, we discuss recent studies and analyze the data supporting the UST approach.