| First Author | Tabaczewski P | Year | 1994 |
| Journal | Proc Natl Acad Sci U S A | Volume | 91 |
| Issue | 5 | Pages | 1883-7 |
| PubMed ID | 8127900 | Mgi Jnum | J:17105 |
| Mgi Id | MGI:65158 | Doi | 10.1073/pnas.91.5.1883 |
| Citation | Tabaczewski P, et al. (1994) Alternative splicing of class Ib major histocompatibility complex transcripts in vivo leads to the expression of soluble Qa-2 molecules in murine blood. Proc Natl Acad Sci U S A 91(5):1883-7 |
| abstractText | Class Ib Qa-2 molecules are expressed in tissue culture cells as approximately 40-kDa membrane-bound, glycophosphatidylinositol-linked antigens and as approximately 39-kDa soluble polypeptides. Recently, alternative splicing events which delete exon 5 from a portion of Qa-2 transcripts were demonstrated to give rise to truncated secreted Qa-2 molecules in transfected cell lines. To determine whether this mechanism operates in vivo and to find out whether Qa-2 can be detected in soluble form in circulation, murine blood samples were analyzed. Critical to these experiments was preparation of an anti-peptide antiserum against an epitope encoded by a junction of exon 4 and exon 6. We find that supernatants of splenocytes cultured in vitro as well as serum or plasma contain two forms of soluble Qa-2 molecules. One form corresponds to a secreted molecule translated from transcripts from which exon 5 has been deleted; the other is derived from membrane-bound antigens or their precursors. The levels of both soluble forms of Qa-2 are inducible upon stimulation of the immune system, suggesting an immunoregulatory role for these molecules or for the mechanism leading to the reduction of cell-associated Qa-2 antigens in vivo. |
