Cytokine Profiling of Subclinical Tick-Borne Infections in Humans

Over many years, tick-borne infections remain one of the most serious threats to human health worldwide. The immune response to these infections in a human after confirmed bite by an infected carrier at the early stages of infection in the absence of clinical symptoms can be the first indicator of the presence of the infectious agent in the body. During viral infection, the concentration of IL-1α, IL-8, IL-10, IL-17A, and IFNγ increases; superoxide dismutase also increases, in contrast to bacterial infections. A slight decrease in the concentration is observed only for receptor antagonist IL-1Ra. During the infection caused by bacterial pathogens, very similar profiles of the innate human immune response are observed: activation of IL-1α, IL-8, and IFNα and suppression of superoxide dismutase, IL-1Ra, and IL-17A production. It has been demonstrated, that the immune response is triggered immediately after infection, and changes in the concentration of the main cytokines in the blood plasma can be detected as early as on days 2-5 after tick bite. These results can be useful in developing new methods of emergency diagnosis and prevention of tick-borne infections.