PROBLEM TO BE SOLVED : To provide a composition comprising a TL1A-Ig fusion protein and use methods thereof for treating diseases and disorders, for example, related to antigen specific immune responses. SOLUTION : Disclosed herein is a combination therapy comprising administration of a TNFRSF25 agonist with an interleukin such as IL-2 and/or a mTOR inhibitor such as rapamycin. Some embodiments provide an isolated or recombinant nucleic acid comprising a polynucleotide sequence encoding a fusion protein, where the fusion protein comprises : (a) a first polypeptide comprising a polypeptide sequence that specifically binds to TNFRSF25 (Tumor Necrosis Factor Receptor Superfamily, Member 25); and (b) a second polypeptide comprising an immunoglobulin (Ig) polypeptide, or a complementary polynucleotide sequence thereof. SELECTED DRAWING : Figure 9 COPYRIGHT : (C)2019, JPO&INPIT