By combining an immune checkpoint inhibitor and an enzyme inhibitor, scientist, at Hokkaido University in Japan, have discovered a way of combating leukaemia in cows.
Researchers have successfully reduced the bovine leukaemia virus (BLV) levels in cows that have presented signs of severe infection.
Such finding can now be utilised to control other diseases presented in cattle while also having a strong possibility of replicating the study in humans.
There is a current BLV endemic in Japan and various other countries across the globe. Unfortunately, before this study conducted by Hokkaido University, there were no other effective treatment available.
Cattle farmers in Japan are facing a serious economic threat. This is due to a total of 3,859 cases of bovine leukaemia being reported amongst the cattle population of Japan in 2018. This is 38 times increase since 1998.
Hokkaido University conducted a study in order to figure out the reason behind the increase in BLV infected cows. One of their findings indicated that bovine leukaemia is closely related to immune suppression induced by immune checkpoint proteins such as PD-L1. Researchers also discover that anti-PD-L1 antibodies could effectively treat BLV infected cattle.
However, this method only treats cows who present the early stages of the bovine leukaemia virus. Following this discovery, researchers focused their attention on prostaglandin E2 (PGE2) which is a bioactive substance that suppresses the immune system by upregulating PD-L1 in cows who present the chronic bacteria disease called Johne’s disease.
The team at Hokkaido University also discovered that cows infected with BLV how increasing blood levels of PGE2 as the disease progresses. The research group discover that they could combat this by introducing a COX-2 inhibitor, which blocks the production of PGE2 and thus triggering a response from the cow’s immune system. When COX-2 is combined with the anti-PD-L1 antibody it furthers the immune system response demonstrating an antiviral effect by reducing viral loads.
The leader of the study, Satoru Konnai of Hokkaido University’s Faculty of Veterinary Medicine and research centre for Zoonosis Control, said “Our study showed that the drug combination has an antiviral effect in BLV-infected animals with high viral levels, which are a major source of infection on farms.”