Adjuvant activity of cordycepin, a natural derivative of adenosine from Cordyceps militaris, on an inactivated rabies vaccine in an animal model

Xin Chen; Boyu Liao; Tianci Ren; Zhipeng Liao; Zijie Huang; Yujuan Lin; Shouhao Zhong; Jiaying Li; Shun Wen; Yingyan Li; Xiaohan Lin; Xingchen Du; Yuhui Yang; Jiubiao Guo; Xiaohui Zhu; Haishu Lin; Rui Liu; Jingbo Wang

doi:10.1016/j.heliyon.2024.e24612

Adjuvant activity of cordycepin, a natural derivative of adenosine from Cordyceps militaris, on an inactivated rabies vaccine in an animal model

Heliyon. 2024 Jan 12;10(2):e24612. doi: 10.1016/j.heliyon.2024.e24612. eCollection 2024 Jan 30.

Authors

Xin Chen^{1

2}, Boyu Liao^{1

2}, Tianci Ren¹, Zhipeng Liao¹, Zijie Huang¹, Yujuan Lin¹, Shouhao Zhong¹, Jiaying Li¹, Shun Wen¹, Yingyan Li¹, Xiaohan Lin¹, Xingchen Du¹, Yuhui Yang^{1

2}, Jiubiao Guo¹, Xiaohui Zhu¹, Haishu Lin^{1

2}, Rui Liu³, Jingbo Wang^{1

2}

Affiliations

¹ College of Pharmacy, Shenzhen Technology University, Shenzhen, 518118, China.
² School of Pharmaceutical Sciences, Health Science Center, Shenzhen University, Shenzhen, 518118, China.
³ Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China.

Abstract

Vaccination is the most feasible way of preventing rabies, an ancient zoonosis that remains a major public health concern globally. However, administration of inactivated rabies vaccination without adjuvants is always inefficient and necessitates four to five injections. In the current study, we explored the adjuvant characteristics of cordycepin, a major bioactive component of Cordyceps militaris, to boost immune responses against a commercially available rabies vaccine. We found that cordycepin could stimulate stronger phenotypic and functional maturation of dendritic cells (DCs). For animal experiments, mice were immunized 3 times with rabies vaccine in the presence or absence of cordycepin at 1-week interval. Analysis of T cell differentiation and serum antibody isotypes showed that humoral immunity was dominant with a Th2 biased immune response. These results were also supported by the raised ratio of follicular helper T cells (T_FH) and germinal center B cells (GCB). Thus, titer of rabies virus neutralizing antibody (RVNAb) and rabies virus-specific memory B cells were both raised as a result. Furthermore, administration of cordycepin did not cause pathological phenomena or body weight loss. The findings indicate that cordycepin could be used as a promising adjuvant for rabies vaccines to get a higher range of protection without any side effects.

Keywords: Adjuvant; Cordycepin; Rabies vaccine.