Grain-sized moxibustion enhances anti-tumor immunity of tumor cell lysate vaccine

Abstract

Abstract Tumor vaccines are an effective immunotherapeutic strategy; however, their clinical effect is limited. Thus, novel methods to improve antitumor immunity of tumor vaccines is urgently required. Grain-sized moxibustion (gM), an ancient Chinese medicine therapy, has been shown to elicit efficient antitumor immune response, this led us to hypothesize that it may benefit tumor vaccines. In this study, the Lewis lung cancer (LLC) xenograft tumor model was established, and LLC whole tumor cell lysate (TL) was used to treat alone or together with gM, which was performed at the acupoint of Zusanli (ST36). T cells, NK cells and dendritic cells (DCs) were accessed by flow cytometer. PK136, GK1.5, 2.43 and propranolol were used for NK cell depletion, CD4+ T cell depletion, CD8+ T cell depletion and β-adrenoceptor blockade, respectively. The results revealed that gM and TL vaccine synergistically inhibited LLC tumor growth, and this effect was abolished completely by CD4+ T cell depletion, partly by NK cell depletion, but not by CD8+ T cell depletion. Mechanically, gM and TL vaccine synergistically promoted DCs activation in tumor-draining lymph node. Like gM, the β-blocker propranolol elicited similar effect for TL vaccine to increase tumor regression and DCs activation. These results implied that gM enhanced TL vaccine by inhibiting β-adrenergic receptor and might be a good adjuvant for tumor vaccines.