Selenium and cellular immunity. Evidence that selenoproteins may be encoded in the +1 reading frame overlapping the human CD4, CD8, and HLA-DR genes

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Ethan W Taylor, Senior Research Professor (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Selenium deficiency can lead to impaired immune function and reduced T-cell counts, as well as various specific disorders. Significantly, in ARC and AIDS patients, a progressive decline in plasma Se, paralleling T-cell loss, has been widely documented. Since evidence now suggests that there is an extremely high turnover of CD4+ T-cells in AIDS patients, with billions of new cells lost and replaced daily, any exceptional requirement for Se in lymphocytes could contribute to this progressive Se depletion. Thus, it may be significant that, over-lapping the known genes in the +1 reading frame, the mRNAs of several T-cell associated genes (CD4, CD8, HLA-DR p33) have open reading frames (ORFs) with as many as 10 in-frame UGA codons (CD4, p33), a clustering that is highly improbable by chance alone, and reminiscent of selenoprotein P, the predominant plasma form of Se. The presence of these ORFs, along with potential stem-loop RNA structures displaying consensus selenocysteine insertion sequences, AUG(N)mAAA(N)nUGR, suggests that these mRNAs may encode selenoproteins, in addition to the known T-cell glycoproteins. If so, the roles of Se in the immune system may be more diverse than previously suspected.

Additional Information

Publication
Biological Trace Element Research 49, 85 (1995). https://doi.org/10.1007/BF02788958
Language: English
Date: 1995
Keywords
Selenium deficiency, cellular immunity, selenoproteins, T-cell associated genes

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