T Cell Invigoration is Associated with the Clinical Response to Anti-PD-1-Based Immunotherapy in Non-Small Cell Lung Cancer

Purpose

Immune checkpoint inhibitors (ICIs) have been developed for clinical application and proven effective for non-small cell lung cancer (NSCLC). Blockade of the programmed cell death 1 (PD-1) protein can partially reinvigorate circulating exhausted-phenotype CD8+ T cells (Tex cells) in preclinical models, however the clinical implication in anti-PD-1-based immunotherapy in NSCLC is unknown.

Methods

Serum specimens were obtained before and during treatment from 145 patients with NSCLC patients who received anti-PD-1 treatment and their prognoses were followed-up. Indicators such as cell subpopulations, T cell invigoration were detected by clinical laboratory testing. Survival curves were estimated by the Kaplan-Meier method, Cox regression analysis was used to identify factors associated with prognoses of NSCLC patients.

Results

The expressions of Ki-67 in PD-1+/CD8+ T cells in most NSCLC patients (97 of 145 cases) increased after treatment. The responding Ki-67+/CD8+ T cell population was mainly CD45RAlo CD27hi, containing cells with high expression of CTLA-4, PD-1, and 2B4 and low expression of NKG2-D (P < 0.0001). The maximum fold change of Ki-67+/PD-1+/CD8+T cells in treatment cycles and the tumor burden determined by imaging may be associated with survival. Patients with higher Ki-67 expression on PD-1+CD8+ T-cells (pretreatment) had statistically significant increased progression-free survival (PFS). A Ki-67 expression to tumor burden ratio greater than 0.6 at the 1st cycle of anti-PD-1 immunotherapy was associated with improvement of PFS and overall survival (P < 0.05).

Conclusion

Activation of circulating Tex cells before or during therapy related to tumor burden may be associated with clinical efficacy of anti-PD-1 immune therapy in NSCLC.

A bimodal burst energy distribution of a repeating fast radio burst source

The event rate, energy distribution and time-domain behaviour of repeating fast radio bursts (FRBs) contain essential information regarding their physical nature and central engine, which are as yet unknown^1,2. As the first precisely localized source, FRB 121102 (refs. ^3-5) has been extensively observed and shows non-Poisson clustering of bursts over time and a power-law energy distribution^6-8. However, the extent of the energy distribution towards the fainter end was not known. Here we report the detection of 1,652 independent bursts with a peak burst rate of 122 h^-1, in 59.5 hours spanning 47 days. A peak in the isotropic equivalent energy distribution is found to be approximately 4.8 × 10³⁷ erg at 1.25 GHz, below which the detection of bursts is suppressed. The burst energy distribution is bimodal, and well characterized by a combination of a log-normal function and a generalized Cauchy function. The large number of bursts in hour-long spans allows sensitive periodicity searches between 1 ms and 1,000 s. The non-detection of any periodicity or quasi-periodicity poses challenges for models involving a single rotating compact object. The high burst rate also implies that FRBs must be generated with a high radiative efficiency, disfavouring emission mechanisms with large energy requirements or contrived triggering conditions.

[Isolation of a metastatic ascitic subpopulation from a human lung adenocarcinoma cell line in nude mice and studies on its biological properties]

An ascitic subpopulation (Anip) was isolated from human lung adenocarcinoma cell line AGZY-83-a through serial intraperitoneal passages in nude mice. Anip manifested a much higher metastatic potential than the parent line. Spontaneous lung metastases occurred in 95% of the mice xenografted intraperitoneally, and the diffuse pattern of the metastases in the lung was very impressive. Anip also differed more or less from the parent line in morphology, growth, rate, electrophoretic mobility, platelet aggregating activity and noticeably in the chromosome histogram. The present model may be used in the study of tumor invasion and metastasis, as large amounts of well dispersed metastatic human carcinoma cells could be reproduced by ascites and much information about the biology of invasion and metastasis of human tumor cells in nude mice could be obtained.