Myeloperoxidase and Lysozymes as a Pivotal Hallmark of Immunity Status in Rabbits

Abstract

Infectious diseases, due to their massive scale, are the greatest pain for all rabbit breeders. Viral infections cause enormous economic losses in farms. Treating sick rabbits is very difficult and expensive, so it is very important to prevent disease by vaccinating. In order to successfully fight viral infections, it is important to know about the immune response of an infected animal. The aim of this study was to analyze the immune response mediated by antimicrobial peptides (myeloperoxidase (MPO) and lysozyme (LZM)) in peripheral blood neutrophils and rabbit serum by non-invasive immunological methods. The study was carried out on mixed breed rabbits that were experimentally infected with two strains (Erfurt and Rossi) of the Lagovirus europaeus/GI.1a virus. It has been observed that virus infection causes changes in the form of statistically significant increases in the activity of MPO and LZM concentration, while in the case of LZM activity only statistically significant decreases were noted. Additionally, clinical symptoms typical for the course of the disease were noted, and the probability of survival of the animals at 60 h p.i. (post infection) was 30% for the Erfurt strain, and −60% for the Rossi strain. The obtained results of MPO and LZMs suggest that these enzymes, especially MPO, may serve as a prognostic marker of the state of the immune system of rabbits.

Immunity against Lagovirus europaeus and the Impact of the Immunological Studies on Vaccination

“…Interestingly, after infection with Lagovirus europaeus /GI.1a, the same parameters decreased, starting at 8–12 h p.i. [ 101 , 152 ], suggesting a different regulation of innate immune mechanisms depending on the genotype of the virus which is probably responsible for the rapid deaths of rabbits in these studies 24–36 h p.i. after RHDVa infection.…”

“…Neutrophils (polymorphonuclear cells, PMNs) are crucial in innate immune responses due to their cytotoxic, phagocytic and neutrophil extracellular trap forming (NET) activities [ 151 ] after the recognition of PAMPs by TLRs. Moreover, neutrophils produce active substances such as lysozyme (LZM), myeloperoxidase (MPO), elastase, esterase, or defensins, which provide anti-viral activities [ 151 , 152 ]. In two studies, the activities of PMNs were measured in the early course of RHD by a variety of parameters (neutrophil phagocytosis, PMN adherence capacity, spontaneous and stimulated metabolic activity, etc.).…”

Diagnosis of a Rabbit Hemorrhagic Disease Virus 2 (RHDV2) and the Humoral Immune Protection Effect of VP60 Vaccine

“…Thus, RHD is included in the list of diseases of the World Organisation for Animal Health (WOAH), which was founded as the Office International des Epizooties [OIE]. The organization is subject to compulsory notification of every case, and an animal suspected or confirmed to have Lagovirus europaeus is immediately euthanized [ 12 , 13 ]. Nowadays, RHD spreads worldwide and causes enormous economic losses to the rabbit breeding industry [ 3 ].…”

Occurrence of Lagovirus europaeus (Rabbit Hemorrhagic Disease Virus) in Domestic Rabbits in Southwestern Poland in 2019: Case Report

“…Because of its severe course, high infectivity, and high mortality rate and because of the high risk and large financial losses for the livestock industry ( 2 , 3 , 11 ), RHD is included in the list of diseases of the World Organisation for Animal Health (WOAH) (founded as the Office International des Epizooties [OIE]) and is subject to compulsory notification of every case ( 22 ). An animal suspected or confirmed to have Lagovirus europaeus is immediately euthanized ( 22 , 23 ). According to data from 2005 to 2018, the occurrence of RHD was reported or suspected in 50 countries, with more than one-half of the reports being from European countries ( 23 ).…”

“…An animal suspected or confirmed to have Lagovirus europaeus is immediately euthanized ( 22 , 23 ). According to data from 2005 to 2018, the occurrence of RHD was reported or suspected in 50 countries, with more than one-half of the reports being from European countries ( 23 ).…”