The invention relates to a gene transfer-based method to protect a subject from Sjogrens syndrome. The method comprises administering to the subject an AAV virion comprising an AAV vector that encodes a soluble CTLA-4 (sCTLA-4) protein. Also provided are sCTLA-4 proteins and nucleic acid molecules that encode such sCTLA-4 proteins. Also provided are AAV vectors and AAV virions that encode a sCTLA-4 protein.