OS12.4.A MHC class II-restricted transgenic T cell receptor therapy targeting mutant capicua transcriptional repressor in experimental gliomas

BACKGROUND

Glioma subtypes are classified according to their characteristic mutations and show a high degree of resistance to standard therapeutic interventions such as radiotherapy and alkylating chemotherapy. Some of these characteristic mutations have shown to generate immunogenic neoepitopes that can be targeted with immunotherapy. 70% of oligodendrogliomas carry capicua transcriptional repressor (CIC) inactivating mutations.

RESULTS

In a screen for potential immunogenic glioma neoepitopes we identified recurrent CIC hotspot mutations at position 215 (CICR215W/Q) expressed in a subset of oligodendrogliomas as an immunogenic major histocompatibility complex (MHC) class II-restricted neoepitopes. Peptide-based vaccination of MHC-humanized mice resulted in the generation of robust mutation-specific T cell responses against CICR215W/Q, restricted to MHC class II. Droplet-based single cell T cell receptor (TCR) sequencing from CICR215W-specific T cell lines enabled retrieval of MHC class II-restricted CICR215W-reactive TCRs. By retroviral transduction of T cells, we established a flow cytometry-based testing platform of retrieved TCRs and were able to show the top reactive TCR against CICR215W to be shared between individual mice. Using a newly developed glioma model in MHC-humanized mice induced by CRISPR-based delivery of tumor suppressor targeting guide RNAs, we show that adoptive intraventricular transfer of CICR215W-specific TCR-transgenic T cells exert anti-tumor responses against CICR215W-expressing syngeneic gliomas.

CONCLUSION

The integration of immunocompetent MHC-humanized orthotopic glioma models in the discovery of shared immunogenic glioma neoepitopes facilitates the identification and preclinical testing of HLA-restricted neoepitope-specific TCRs for locoregional TCR-transgenic T cell adoptive therapy.

Successful stenting of a complex inferior vena cava stenosis using a modified sharp recanulization technique

We describe a case of a 30-year-old male who presented with features of noncirrhotic portal hypertension, who was diagnosed to have inferior vena cava (IVC) obstruction. IVC angiogram and ultrasound study revealed a long-segment (36 mm long), chronic total thrombotic occlusion that was dilated and stented with a satisfactory end result. The unique feature of this case is a modified sharp recanulization technique involving the use of Brokenborough (septal puncture) needle and Mullin dilator to create a track in such a long, chronic total occlusion under simultaneous ultrasound and fluoroscopic guidance.

Broken guidewire fragment: a simplified retrieval technique

We report a technique for retrieval of a broken angioplasty wire fragment from the coronary system using a more simplified technique that does not involve the use of a snare or any other retrieval tool. With the use of an additional angioplasty wire and a balloon catheter, we could safely remove the broken wire fragment from the coronary system and circulation in a very short time.

Cisapride use during human pregnancy: a prospective, controlled multicenter study

The objective of this prospective multicenter study was to determine whether cisapride is associated with increased risk of malformations, spontaneous abortions, or decreased birthweight when used during pregnancy. Cases were paired for age, smoking, and alcohol consumption with controls exposed to nonteratogens, as well as with disease-paired controls. One hundred and twenty-nine pregnant women were exposed to cisapride during pregnancy, including 88 during the period of fetal organogenesis. There were no differences in maternal history, birthweight, gestational age at delivery, and rates of livebirths, spontaneous or therapeutic abortions, fetal distress, and major or minor malformations among groups. It is concluded that exposure to cisapride during pregnancy is not associated with a major increased risk of malformations or spontaneous abortions or with decreased birthweight.