Comparison of the Transcriptomes and Proteomes of Serum Exosomes from Marek’s Disease Virus-Vaccinated and Protected and Lymphoma-Bearing Chickens

Abstract

Marek’s disease virus (MDV) is the causative agent of Marek’s disease (MD), a complex pathology of chickens characterized by paralysis, immunosuppression, and T-cell lymphomagenesis. MD is controlled in poultry production via vaccines administered in ovo or at hatch, and these confer protection against lymphoma formation, but not superinfection by MDV field strains. Despite vaccine-induced humoral and cell-mediated immune responses, mechanisms eliciting systemic protection remain unclear. Here we report the contents of serum exosomes to assess their possible roles as indicators of systemic immunity, and alternatively, tumor formation. We examined the RNA and protein content of serum exosomes from CVI988 (Rispens)-vaccinated and protected chickens (VEX), and unvaccinated tumor-bearing chickens (TEX), via deep-sequencing and mass spectrometry, respectively. Bioinformatic analyses of microRNAs (miRNAs) and predicted miRNA targets indicated a greater abundance of tumor suppressor miRNAs in VEX compared to TEX. Conversely, oncomiRs originating from cellular (miRs 106a-363) and MDV miRNA clusters were more abundant in TEX compared to VEX. Most notably, mRNAs mapping to the entire MDV genome were identified in VEX, while mRNAs mapping to the repeats flanking the unique long (IRL/TRL) were identified in TEX. These data suggest that long-term systemic vaccine-induced immune responses may be mediated at the level of VEX which transfer viral mRNAs to antigen presenting cells systemically. Proteomic analyses of these exosomes suggested potential biomarkers for VEX and TEX. These data provide important putative insight into MDV-mediated immune suppression and vaccine responses, as well as potential serum biomarkers for MD protection and susceptibility.

Mapping QTL Associated with Resistance to Avian Oncogenic Marek’s Disease Virus (MDV) Reveals Major Candidate Genes and Variants

“…These studies are usually done, not with relevant commercial lines, but with experimental or inbred lines and examine whole tissues, although recent work has investigated the host response to MDV in specific cells such as macrophages, which are an early target for the virus [ 21 , 22 ]. Recent studies on the role of long non-coding RNAs [ 23 , 24 ] and microRNAs (in both the host and virus) have also been carried out [ 25 , 26 , 27 ], including a study of serum exosomes from lymphoma-bearing birds [ 28 ]. In addition, the role of epigenetics in resistance to MDV has been studied, with regions of differential methylation between susceptible and resistant lines of birds highlighted [ 29 , 30 ].…”

Effect of gga-miR-155 on cell proliferation, apoptosis and invasion of Marek’s disease virus (MDV) transformed cell line MSB1 by targeting RORA

“…Marek's disease virus (MDV) is an oncogenic herpesvirus, reclassified as the Gallid alphaherpesvirus 2 (GaHV2) [1]. It is the causative agent of Marek's disease (MD), which is characterized by complex clinical syndromes, including immune suppression, paralysis, neurological signs and lesions, and the rapid formation of CD4 + T-cell lymphomas [2][3][4], and is responsible for considerable losses to the poultry industry worldwide. Although a vaccine is available against MD, eruptions are common even in immunized chicken flocks, likely due to intensive farming, incomplete immunization and increasing virulence [5][6][7][8].…”

“…MDV-miR-M4 is highly expressed in virus-infected CEFs, MDV-induced tumor tissues, lymphoblastoid cell lines and serum exosomes [4,27,28], and promotes MDV tumorigenesis. In contrast, miR-155, gga-miR-181a and gga-miR-26a are downregulated in MDV-transformed T lymphocyte lines, MDV-induced tumors and MDV-infected peripheral blood lymphocytes [29,30].…”

Effect of gga-miR-155 on Cell Proliferation, Apoptosis and invasion of Marek’s disease Virus (MDV) transformed cell line MSB1 by targeting RORA

“…Marek's disease virus (MDV) is an oncogenic herpesvirus, reclassified as the Gallid alphaherpesvirus 2 (GaHV2) [1] . It is the causative agent of Marek's disease (MD), which is characterized by complex clinical syndromes, including immune suppression, paralysis, neurological signs and lesions, and the rapid formation of CD4 + T-cell lymphomas [2][3][4] , and is responsible for considerable losses to the poultry industry worldwide. Although a vaccine is available against MD, eruptions are common even in immunized chicken flocks, likely due to intensive farming, incomplete immunization and increasing virulence [5][6][7][8] .…”