The project builds on collecting samples from patients enrolled in the the hepatitis B cohort and in the Terminator 2 study. Preliminary results showed that γδ T cell numbers are elevated in HBV patients as compared to healthy controls. So far, nothing is known about the phenotype, TCR repertoire, and antiviral potential of γδ T cells in hepatitis B. While it is known that HBV- specific αβ T cell responses are important for control and clearance of HBV, we hypothesize that γδ T cell responses are also critical for patients which cleared the infection after stop of NA treatment. To monitor T cell responses in the course of infections, we have established NGS technologies that provide comprehensive access to complex antigen receptor repertoires.
This project comprises phenotypical, functional and T cell receptor (TCR) analyses of blood-derived αβ and γδ T cells. Specifically, phenotypical and functional HBV-core specific CD4 and CD8 T cell responses will be analyzed in HLA-typed patients using 16 parameter flow cytometry (e.g. HLA-DRB1 for CD4 and HLA-A2+ for CD8). In parallel we will analyze the TCR repertoire of the dominant CD8 and CD4 T cell responses after FACS-sorting.
To determine and investigate the role of γδ T cells in the Terminator 2 study patient cohort, we use multiplex NGS γδ TCR analyses. In particular, we have set up a pipeline to investigate γδ TCR repertoires by RNA-based multiplex PCR amplicon sequencing and αβ TCR repertoires by RNA-based 5’-RACE PCR amplicon sequencing.