The present invention provides an immunotherapeutic composition for use in combination with one or more MDSC (Myeloid-derived suppressor cells) modulator(s) and a kit of parts comprising such components as well as methods using such components in combination. The invention also provides the use of Phosphodiesterase-5 (PDE5) inhibitors for reversing immunosuppression in chronic infectious diseases. The invention is of very special interest in treating or preventing diseases, especially chronic infectious diseases such as hepatitis B.本發明係提供一種免疫治療組成物，用於與一或多種MDSC (骨髓-衍生抑制細胞)調節劑組合，以及一種包含這些成分之套組，以及組合使用這些成分之方法。本發明亦提供一種磷酸二脂酶-5(PDE5)抑制劑之用途，用於逆轉慢性感染疾病之免疫抑制作用。本發明特別適用於治療或預防疾病，尤其是慢性感染疾病如B型肝炎。
