Gamma delta intraepithelial lymphocytes drive tumor necrosis factor-alpha responsiveness to intestinal iron challenge: relevance to hemochromatosis.

The dependence of intestinal epithelial cell (IEC) growth and differentiation on intraepithelial lymphocytes (IELs) expressing the gamma/delta (gamma delta) T-cell receptor (TCR), suggested a potential role for gamma delta + IELs in the regulation of iron absorption. We therefore examined the levels of hepatic iron and the IEL cytokine responses in C57BL/6J control and class I and TCR knockout lines (placed on a C57BL/6J genetic background) following the administration of supplemental dietary iron. The highest level of liver iron was found in the beta 2-microglobulin knockout (beta 2m-/-) mice followed by the TCR-delta knockout (TCR delta-/-) animals.

Studies of the 6.7 family of dispersed genomic fragments within the MHC class I Region.

Searches for MHC-encoded disease susceptibility genes have led to considerable knowledge of the content of the class I region. In an effort to further understand the nature of the five 6.7 family members previously mapped to this region of the genome, we have further analyzed the cross-reactive members of the family and have observed additional genomic instability within the HLA-A subregion.

46,XX, inv(6)(p21.1p23) in a pedigree with hereditary haemochromatosis.

Hereditary haemochromatosis (HFE) is a recessive genetic disease of iron overload which has been shown by linkage analysis to reside on the short arm of chromosome 6, close to the major histocompatibility complex (MHC). Positional cloning of the putative HFE locus has been hampered, in part, by the lack of a structural alteration on 6p. In this report, we describe a pedigree with HFE which carries a balanced paracentric inversion of chromosome 6, inv(6)(p21.