Substances in tick spit actuate insusceptible reaction smothering proteins in cattles

Overview

• Post By : Kumar Jeetendra


• Source: Hokkaido University


• Date: 28 Jan,2021

Scientists from Hokkaido University, Japan and Universidade Federal do Rio Grande do Sul and Universidade Federal do Rio de Janeiro, Brazil, have revealed that substances in tick saliva trigger immune response-suppressing proteins in cows that facilitates the transmission of tick-borne diseases. The finding was published in the journal Scientific Reports and could assist in the development of alternative control strategies.

The Asian blue tick, Rhipicephalus microplus, feeds on cattle, causing skin lesions, chronic blood loss and transmission of disease-causing parasites. The costs of treating and preventing disease and reduction of some cattle are considerable in many parts of the world.

Some ticks have developed resistance against currently used acaricides, the tick equal of insecticides. To develop alternative strategies that can better protect cattle, like vaccines, scientists will need to better understand tick infections in the molecular level. By way of example, scientists know that tick saliva inhibits the immune response in cattle, facilitating the transmission of tick-borne parasites, however, the specific process has not been fully clarified.

Infectious disease veterinarian, Satoru Konnai, and scientists at Hokkaido University in Japan and colleagues in Brazil investigated what happens to immune cells when they are exposed to tick saliva. The team found that substances in tick saliva, likely a lipid chemical called a prostaglandin, increase the expression of two particular cell membrane proteins on some immune cells.

This means that the cattle’s immune response is less able to fight invading tick-borne parasites.

However future studies will need to confirm if prostaglandin E2 plays a direct role in suppressing the cattle immune reaction. Also, as this study involved cells in the laboratory, the group says further research in live cattle is needed.

Our findings suggest that Asian blue tick saliva inhibits the immune responses of helper T cells, at least in part, via the interaction between PD-1 and PD-L1.”

Satoru Konnai, Associate Professor, Infectious disease veterinarian, Laboratory of Infectious Diseases, Hokkaido University

Associate Professor Satoru Konnai of the Laboratory of Infectious Diseases at Hokkaido University conducts research on the development of novel therapeutic strategy for intractable diseases control in animals; the pathogenesis of bovine leukemia; analysis of mechanism of tick-borne pathogen transmission and growth of anti-tick vaccines.