![pclp no2 pclp no2](https://livescreenshot-10063587.file.myqcloud.com/2021-06-02/3954_58005-screenshot-04-37-01-374x210.jpg)
Moreover, T lymphocytes extracted from both tolerated and rejected grafts are similarly cytotoxic in vitro against donor cells. In both cases, the graft is heavily infiltrated by recipient cells, and class I and class II molecules of the major histocompatibility complex are strongly expressed. Tolerance (> 100 days) can be induced by pretransplant donor-specific blood transfusions. In the spleen of normal rats, we detected cytotoxic cells directed against cells expressing beta-gal after the injec.Ĭongenic LEW.1W (RT1u) heart grafts in LEW.1A (RT1u) recipient rats are rejected within 15 +/- 6 days. Transgenic rats tolerant for cytoplasmic beta-gal, or normal rats depleted in CD8 T lymphocytes, steadily expressed the beta-gal vector. These observations suggested the elimination of transduced cells by an immune response. Extinction was associated with liver inflammation on tissue sections and appearance of antibodies against the transgene product, while vector genomes became undetectable in liver tissue by PCR. In striking contrast, we observed a rapid extinction when the intravenous injection of a high input of nuclear beta-galactosidase (beta-gal) expression vector, one day after partial hepatectomy, led to a significant proportion of transduced cells in the liver. Transgene expression may be sustained for months without immune response. Vectors derived from oncoretroviruses can transduce a small proportion of hepatocytes when injected in the regenerating liver.