The function of thymic reticuloepithelial cells in New Zealand mice

This study was undertaken to clarify the function of thymic reticuloepithelial cells (TRC) in the New Zealand black (NZB) mouse as a model animal of human autoimmune disease. Attention was focused on whether or not any defect in the TRC function participating in the maturation process from immature T cells to mature T cells was present. Precursor T cells isolated from bone marrow cells were cultured with TRC. Induction of Thy-1.2 antigen on the surface of precursor T cells was measured, in addition to the increased responsiveness of precursor T cells to T-cell mitogens and in mixed lymphocyte reaction (MLR). When NZB mouse precursor T cells were cultured with normal mouse TRC, the induced T-cell function proved to be similar to the function noted when normal mouse precursor T cells were cultured with normal mouse TRC. On the other hand, when normal mouse precursor T cells were cultured with NZB mouse TRC, the induced T-cell function proved to be inferior to the one noted in culture with normal mouse TRC. From these results, it was concluded that the NZB mouse had nothing remarkable in precursor T cells, but something abnormal in the TRC function.