PD-1-CD28 fusion protein strengthens mesothelin-specific TRuC T cells in preclinical solid tumor models

BACKGROUND

T cell receptor fusion constructs (TRuC) consist of an antibody-based single chain variable fragment (scFv) fused to a T cell receptor chain (TCR) and allow recognition of cancer cells in an HLA-independent manner. Unlike chimeric antigen receptors (CAR), TRuC are integrated into the TCR complex resulting in a functional chimera with novel specificity, whilst retaining TCR signaling. To further enhance anti-tumor function, we expressed a PD-1-CD28 fusion receptor in TRuC T cells aiming to prevent tumor-induced immune suppression and T cell anergy.

METHODS

The activation level of engineered T cells was investigated in co-culture experiments with tumor cells followed by quantification of released cytokines using ELISA. To study T cell-mediated tumor cell lysis in vitro, impedance-based real-time tumor cell killing and LDH release was measured. Finally, two xenograft mouse cancer models were employed to explore the therapeutic potential of engineered T cells.

RESULTS

In co-culture assays, co-expression of PD-1-CD28 enhanced cytokine production of TRuC T cells. This effect was dependent on PD-L1 to PD-1-CD28 interactions, as blockade of PD-L1 amplified IFN-γ production in unmodified TRuC T cells to a greater level compared to TRuC-PD-1-CD28 T cells. In vivo, PD-1-CD28 co-expression supported the anti-tumor efficacy of TRuC T cells in two xenograft mouse cancer models.

CONCLUSION

Together, these results demonstrate the therapeutic potential of PD-1-CD28 co-expression in TRuC T cells to prevent PD-L1-induced T cell hypofunction.

T cells armed with C-X-C chemokine receptor type 6 enhance adoptive cell therapy for pancreatic tumours

The efficacy of adoptive cell therapy for solid tumours is hampered by the poor accumulation of the transferred T cells in tumour tissue. Here, we show that forced expression of C-X-C chemokine receptor type 6 (whose ligand is highly expressed by human and murine pancreatic cancer cells and tumour-infiltrating immune cells) in antigen-specific T cells enhanced the recognition and lysis of pancreatic cancer cells and the efficacy of adoptive cell therapy for pancreatic cancer. In mice with subcutaneous pancreatic tumours treated with T cells with either a transgenic T-cell receptor or a murine chimeric antigen receptor targeting the tumour-associated antigen epithelial cell adhesion molecule, and in mice with orthotopic pancreatic tumours or patient-derived xenografts treated with T cells expressing a chimeric antigen receptor targeting mesothelin, the T cells exhibited enhanced intratumoral accumulation, exerted sustained anti-tumoral activity and prolonged animal survival only when co-expressing C-X-C chemokine receptor type 6. Arming tumour-specific T cells with tumour-specific chemokine receptors may represent a promising strategy for the realization of adoptive cell therapy for solid tumours.

[Percutaneous fixation--or "doubling" the left-sidedness-- and righting of the displaced abomasum in milk cows]

In the time from 1st of May 1991 up to the 30th April 1995 in total 101 percutaneus fixations of displaced amomasi were done according to the method of GRYMER and STERNER (1982). In 90 cases it was a displacement to the left side (plus one rezidiv) and eleven cases to the right side. This method of fixation was not difficult. The milkyields of these cows in the year before the illness was higher than the average of the herds. In the year of the percutaneous fixation the milk yield went down, ever it was higher (655 kg = 9.1%) than the average. That of the young cows in first lactation was a little bit lower than the average (3.2%) but in the following year it was a little bit higher (50 kg). In total 17 patients with left side and four cows with right side displacement died or had be slaughtered. First week after surgery eight cows had to be killed due to: hepatitis (5x), foreign body (1x), peritonitis (1x) after fixation, perforated wall of the abomasum (1x). The examination shows, that a great number of cows after percutaneous abomasopexie according to GRYMER and STERNER (1982) can be used for a longer time with economically satisfying results.