Journal Article

Immune cell pathology in rabbit hemorrhagic disease

Abroyan, Liana Onik, Sargsyan, Mariam Armenak, Arzumanyan, Hranush Harutyun, Hakobyan, Lina Hayrapet, Avetisyan, Aida Sergey, Krasnikov, Nikolay Fyodor, Karalova, Elena Michael, Matevosyan, Hripsime Shavarsh, Semerjyan, Anna Babken, Semerjyan, Zara Babken, Manukyan, Davit Mihran, Karalyan, Zaven Alexandr

2019

Overview

Aim: The aim of this research was to study the effect of rabbit hemorrhagic disease virus (RHDV) on the host immune response by examining the cellular composition/pathology of lymphoid organs and serum levels of tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ). Materials and Methods: Nine adult rabbits were inoculated with 1 ml of 10% infected liver homogenate, and three rabbits served as controls. The rabbit hemorrhagic disease (RHD)-induced animals were studied on 3 consecutive days post-infection. Diagnosis of RHD was made through routine hemagglutination tests and the polymerase chain reaction. Blood smears and tissue samples from bone marrow (BM), spleen, lymph nodes, and liver were analyzed for cell composition and cytopathology. Serum levels of TNF-α and IFN-γ were measured by enzyme-linked immunosorbent assay. Results: RHD showed a decreased absolute cell count of blood as well as lymph nodes, spleen, and BM cell populations with marked left shift. This was seen as a progressive rise in immature and blast cells. Quantitative cellular changes were accompanied by an increase in specific inflammatory cytokines. Immunocytopathological alterations were evidenced by: Vacuolized, hyperactivated tissue macrophages, finding of Dohle bodies in neutrophils, and activated lymphocytes with increased nuclear-cytoplasmic ratio. Cytoplasmic eosinophilic viral inclusions found in tissue (liver, spleen, and BM) macrophages were shown for the 1st time in RHD. Megakaryocytic emperipolesis was a common feature of RHD. Conclusion: These studies suggest that RHDV induces pathology in leukocytes due to hyperactivation with left shift (toward immature stages of the different cell lineages). Macrophages are increased in number and show an expressed cytopathic effect often accompanied by viral eosinophilic cytoplasmic inclusions. They also developed a secretory activation (increased levels of pro-inflammatory cytokines). Keywords: cytopathology, emperipolesis, eosinophilic viral inclusions, immune response, macrophages, rabbit hemorrhagic disease virus.

• Publisher: Veterinary World
• Subject: Analysis / Biological response modifiers / Blast cells / Bone marrow / Cell activation / Cytokines / Cytopathology / Emperipolesis / Enzyme-linked immunosorbent assay / Enzymes / eosinophilic viral inclusions / Explosions / Hemagglutination / Hemorrhagic disease / Hepatocytes / Immune response / Inclusion bodies / Inflammation / Interferon / Leukocytes (eosinophilic) / Leukocytes (neutrophilic) / Liver / Lymph nodes / Lymphatic system / Lymphocytes / Macrophages / Medical research / Methylene blue / Necrosis / Pathology / Polymerase chain reaction / Rabbit hemorrhagic disease / rabbit hemorrhagic disease virus / Rabbits / Serum levels / Spleen / Tumor necrosis factor / Tumor necrosis factor-TNF / Tumor necrosis factor-α / Tumors / γ-Interferon