Mechanism of Immunity to Tick infestation in Livestock

Abstract

Immunological interaction at the tick host interface involves both innate and acquired host defenses against infestation and Immunomodulatory countermeasures by thetick. Acquired resistance to tick infestation involves humoral and cellular immlmoregulatory effector pathways. Tick-borne disease-causing agentspr exploit tick suppression of host defenses during transmission and initiation of infection. Because of the public health importance of ticks and tick- borne diseases, it is crucial that we understand these interactions and exploit them in novel immunological control. The tick-host-pathogen interface is characterized * Disease-causing agents transmitted by blood- by complex immunological interactions. Immuno- feeding arthropods are significant public health logical interaction at the tick host interface involve concerns. In addition to the emergence of new both innate and acquired host defenses against diseases, many well-recognised vector-borne diseases infestation and Immunomodulatory countermeasures are occurring more frequently and are increasing the by the tick. The cellular and molecular immunological range over which they occur. Many factors contribute bases of these host-parasite relationships are being to the emergence and re-emergence of arthropod- defined. Acquired resistance to tick infestation borne diseases: insecticide/acaricide resistance; drug involves humoral and cellular immlmoregulatory resistance; economic and social factors; environ- effector pathways. It impairs tick engorgement, ova mental change; and genetic changes in the vector- production, and viability Ticks responds by borne pathogens. suppressing antibody production, complement and * On a global basis, ticks are second only to cytokine elaboration by both antigen-presenting cells mosquitoes as vectors of disease-causing agents to and specific T cell subset . Tick countermeasures to humans, and they are the most important arthropod host defenses reduce T-lymphocyte proliferation, transmitting pathogens to other animal species.The elaboration of the Th1 cytokines interleukin-2 and public health importance of ticks is not diminishing. interferon-y, production of macrophage cytokines Furthermore, new tick-borne disease causing agents interleukin-1 and tumor necrosis factor, and antibody are being discovered. Lyme borreliosis, caused by responses. Tick-borne disease-causing agentspr Borrelia burgdorferi, occurs in regions with temperate exploit tick suppression of host defenses during climates, and it is the most frequently reported vector- transmission and initiation of infection. Because of the borne disease in the United States. In the United public health importance of ticks and tick-borne States, the vectors of B. burgdorferi are Ixodes diseases, it is crucial that we understand these scapularis in the east and midwest and Ixodes interactions and exploit them in novel immunological pacificus in the west. In addition to B. burgdorferi, I. control.The dynamic balance between acquired scapularis is a vector of the human pathogens: resistance and tick modulation of host immunity Babesia microti; the causative agent of human affects engorgement and pathogen transmission. So a granulocytic ehrlichiosis and a recently described thorough understanding of mechanism of host encephalitis-like virus, In addition, Ehrlichia immunity to ticks is essential for rational devlopement chaffeensis, transmitted by Amblyomma americanum, of antitick vaccine.