Combined antitumor effects of anti-EGFR variant III CAR-T cell therapy and PD-1 checkpoint blockade on glioblastoma in mouse model.

Glioblastoma is one of the deadliest cancers. Chimeric antigen receptor (CAR)-T cell therapy against solid tumors has been far from satisfactory largely due to the immunosuppressive tumor microenvironment, such as PD-1 mediated T cell exhaustion. In the present study, we investigated the combined antitumor effects of anti-EGFR variant III CAR-T cell therapy and PD-1 checkpoint blockade on glioblastoma in mouse model. The results demonstrated that CAR-T cells with PD-1 blockade exhibit higher killing efficiency in vitro. Additionally, CAR-T cells with PD-1 blockade showed more effective and persistent therapeutic effects on glioblastoma and led to significantly increased number of tumor infiltrating lymphocytes (TILs) in the mouse model. In conclusion, PD-1 checkpoint blockade significantly enhanced the antitumor activity of anti-human EGFRvIII CAR-T cells by overcoming TILs exhaustion. The outcomes of the present study provide a novel strategy for improving the potency of CAR-T cell therapies in solid tumors.

Development of a SYBR Green real-time RT-PCR assay for the detection of avian encephalomyelitis virus.

Avian encephalomyelitis virus (AEV) causes epidemic diseases in poultry worldwide. A SYBR Green real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay was developed for the rapid detection and quantitation of AEV in this study. A pair of specific primers was designed in the highly conserved VP1 gene of this virus. When comparing this assay with conventional RT-PCR, the rRT-PCR assay was 100 times more sensitive and could detect levels as low as 10 standard DNA copies of the AEV SX strain. The specificity of this technique was evaluated in five other avian pathogens. The AEV RNA was detected as early as three days post-infection in chicken embryos. All 18 clinical chicken brains collected from an AEV outbreak in Northwestern China were detected to be positive (100%) using the rRT-PCR assay. However, only 5 of the 18 samples were positive (28%) using the conventional RT-PCR. The results were confirmed by virus isolation in chicken embryos. This high sensitivity, specificity, and simplicity of the SYBR Green rRT-PCR approach can be a more effective method than the conventional one for AEV diagnosis and surveillance.

Phylogenetic and pathogenic analyses of two virulent Newcastle disease viruses isolated from Crested Ibis (Nipponia nippon) in China.

The crested ibis is one of the most endangered birds in the world, found only in Shaanxi Province in Central China, and it has been reintroduced in Sadogashima in Japan. Two Newcastle disease virus (NDV) isolates were collected from sick crested ibises, and their pathogenic and phylogenetic characteristics were investigated. The results showed that they are virulent, with intracerebral pathogenicity indices of 1.46-1.83 and a mean time of death of 54.4-84.4 h. They shared the same virulent motif (112)-R-R-Q-K-R-F-(117) at the F protein cleavage site. The phylogenetic analysis revealed that both isolates were clustered with class II NDVs, with one in genotype VIId and another in a novel genotype (provisionally designated as VIi). The two isolates shared high homology with the strains isolated from poultry flocks in the same region from 2006 to 2010. We first isolated and characterised the NDV isolates from crested ibises, one of which showed new genetic characteristics and formed a new subgenotype with isolates from pigeons and ostriches in the same area. These data are useful for further epidemiological studies on NDV and the protection of crested ibises.