The murine homolog of the HIN 200 family, Ifi 204, is constitutively expressed in myeloid cells and selectively induced in the monocyte/macrophage lineage.

To examine the expression of Ifi 200 genes in vivo and add new information about their function, polyclonal monospecific rabbit antibodies, designated N-term or C-term, were raised against both the N-terminus and C-terminus of the 204 protein (p204) respectively. Western blotting analysis demonstrated that p204 and D3, another member of the Ifi 200 gene family, are constitutively expressed, though at different degrees, in bone marrow, thymus and lymph nodes, and barely detectable in the spleen. Poly rI:rC treatment did not modulate their expression.

Inhibition of cell proliferation by the interferon-inducible 204 gene, a member of the Ifi 200 cluster.

The role of the IFN-inducible p204 as growth regulator was investigated by transfecting an expression vector constitutively expressing p204 into several cell lines. Like pRB and p107, p204 is a potent growth inhibitor in sensitive cells, as demonstrated by the cell focus assay. Since stable transfectants of sensitive lines constitutively overexpressing p204 could not be established in vitro, we inserted the 204 cDNA into a vector bearing an heavy-metal-inducible promoter.

Restriction of the T-cell receptor V delta gene repertoire is due to preferential rearrangement and is independent of antigen selection.

To determine whether the limited V gene usage by the T-cell receptor delta (TCRD) chain is dictated by preferential rearrangement or by antigen selection, we characterized and compared the TCRDV gene repertoire of the productive with that of the unproductive allele in 80 human TCRG/TCRD clones. Six different V genes were found on the expressed allele; two of them, provisionally named DV7 and DV8, have not been described before on the surface of TCRG/TCRD T cells. Overall, six V genes and six non-V elements were isolated from the unproductive allele.