Analysis Of The TCR Repertoire In Patients With Advanced Non-small Cell Lung Cancer Before And After Anticancer Treatment

Background:Non-small cell lung(NSCLC)cancer is the most frequent types of lung cancer,which the incidence rate is high,the treatment effect and prognosis is poor,which is seriously harmful to human health.Comprehensive and objective evaluation criteria of curative effect is lacking.The search for new biomarker for non-small lung cancer to evaluate the curative effect has become an urgent problem to be solved.Recent studies have shown that the development and prognosis of non-small cell lung cancer is closely related to the immunity.T lymphocyte plays a central role in the immune system.But it is basically based on the study of T lymphocyte subsets,and we need to further study the sequence information and diversity variation of T cell receptor(TCR)combined with tumor antigen.Immune repertoire refers to the diverse collection of all immune cells in an individual,which reflects the state of immune function of the body.High-throughput sequencing is a new sequencing technology after Sanger sequencing,which can cost less but generate a great number of sequences,also can make a comprehensive analysis the transcriptome and genome.Objective:1.To determine the changes of immune function of treatment-naive NSCLC patients before and after anticancer treatment.2.To compare the difference ofthe frequency of V gene and J gene usage,T lymphocyte diversity between NSCLC groups and healthy people.3.To evaluate the relationship between T lymphocyte diversity and clinical manifestation.4.To explore the changes of TCR diversity in NSCLC patients before and after anticancer treatment.Methods:32 cases of treatment-naive NSCLC patients from Foshan First Peoples Hospital were included in this study.All patients received targeted therapy or chemotherapy,and peripheral blood samples were collected at baseline and after anticancer treatment.16 age-matched and healthy people acted as controls.2.Ficoll method was used to separate peripheral lymphocytes from samples,and RNA was extracted for reverse transcription,and then the sequence information was detected by high-throughput sequencing.The CDR3 sequence was translated by data analysis.3.The diversity of TCR repertoire was quantified by the Shannon index.4.Differences between the two were calculated by the Mann-Whitney U test.Relations between data were compared by Spearman’s rank test.Differences in PFS between the two groups were compared using the Cox proportional hazards regression model.All data analyzes were judged by SPSS 26.0.A two-sided P<0.05 was regarded as having statistical significance.Results:1.Compared with the healthy people,the Shannon index of the TCR in the NSCLC patients were significantly reduced(P<0.05).There were significant differences in the frequency of 27 V genes and 1 J genes between groups.2.TCR repertoire diversity was lower in NSCLC patients with clinical features such as the tumor size greater than 3 cm.Furthermore,the levels of neutrophil/lymphocyte ratio(NLR)and lactate dehydrogenase(LDH)were negatively corelated with TCR repertoire diversity.3.The patients with higher TCR diversity or increased diversity had longer PFS.Conclusion:1.NSCLC patients had unique immunological characteristics.The diversity of NSCLC patients’ TCR repertoire was lower than that of healthy controls.2.Anticancer treatment could reconstruct the TCR repertoire in NSCLC patients,and the diversity of TCR repertoire could be used as a indicators to predict the clinical response.