The present invention provides novel peptides that facilitate the opening of mammalian tight junctions, i.e. tight junction agonists. The present invention also provides methods for the treatment of disease by administering to a subject suffering from the disease a composition comprising a peptide tight junction agonist of the invention in combination with a therapeutically effective amount of an active agent.本發明提供促進哺乳動物緊密連接之開放的新穎胜肽,亦即緊密連接促效劑。本發明亦提供藉由將包含本發明之胜肽緊密連接促效劑與治療有效量之活性劑之組合的組合物投與罹患疾病之個體來治療疾病的方法。