Endogenous retroviruses expressed in human tumours cannot be used as targets for anti-tumour vaccines

Highlights • Endogenous retroviruses are expressed in human tumours. • In some animal tumour models passive and active immunization against retroviral antigens expressed in the tumour tissues helped to inhibit tumour development. • Human tumour cells expressing human endogenous retroviruses (HERVs) transplanted into animals were also inhibited by antibodies against HERVs. • Since HERVs are also expressed in the human placenta, on human stem cells and immune cells, immunisation against HERVs may be harmful if applied.
Many tumour cells express on their surface proteins of endogenous retroviruses (ERVs) and there are suggestions to use these retroviral antigens as target for anti-tumour vaccines. However, until now there is no convincing data showing that this strategy works, in contrast, there are considerations suggesting that this strategy may be harmful if applied.