OBJECTIVETo explore a new immunotherapy against allergic rhinitis.

METHODSThe recombinant protein of CTLA4 extracellular domain was obtained through construction of CTLA4-yeast expression system. The allergic rhinitis in mice was induced by sensitizing and challenging with ovalbumin (OVA). The allergic rhinitis related symptoms and the morphological changes in nasal mucosa were compared between the allergic rhinitis group and the CTLA4 extracellular domain group treated with CTLA4 extracellular domain before each challenge by ways of intraperitoneal injection.

RESULTSCTLA4 extracellular domain with a molecular weight of 28 000, which was confirmed by Western blot, could be generated through CTLA4-yeast expression system. The purified CTLA4 extracellular domain could inhibit T cells proliferation in mixed lymphocyte reaction with a inhibitory rate of 95.4%. The mice in allergic rhinitis group appeared typical allergic rhinitis symptoms after OVA challenge, such as rhinorrhea and sneeze. Meanwhile the nasal pathological studies showed edema and congestion in mucosa tissue and local influx of inflammatory cells. Whereas in CTLA4 extracellular domain group, the nasal symptoms were rarely observed, and the pathological change in nasal mucosa was significantly abated.

CONCLUSIONSThe protein of CTLA4 extracellular domain could prevent the allergic rhinitis in mice. The underlying mechanism of which might be the inhibition of the T cell activation.