Chicken or Porcine Aminopeptidase N Mediates Cellular Entry of Pseudoviruses Carrying Spike Glycoprotein from the Avian Deltacoronaviruses HKU11, HKU13, and HKU17.

Members of deltacoronavirus (DCoV) have mostly been identified in diverse avian species as natural reservoirs, though the porcine DCoV (PDCoV) is a major swine enteropathogenic virus with global spread. The important role of aminopeptidase N (APN) orthologues from various mammalian and avian species in PDCoV cellular entry and interspecies transmission has been revealed recently. In this study, comparative analysis indicated that three avian DCoVs, bulbul DCoV HKU11, munia DCoV HKU13, and sparrow DCoV HKU17 (Chinese strain), and PDCoV in the subgenera Buldecovirus are grouped together at whole-genome levels; however, the spike (S) glycoprotein and its S1 subunit of HKU17 are more closely related to night heron DCoV HKU19 in Herdecovirus. Nevertheless, the S1 protein of HKU11, HKU13, or HKU17 bound to or interacted with chicken APN (chAPN) or porcine APN (pAPN) by flow cytometry analysis of cell surface expression of APN and by coimmunoprecipitation in APN-overexpressing cells. Expression of chAPN or pAPN allowed entry of pseudotyped lentiviruses with the S proteins from HKU11, HKU13 and HKU17 into nonsusceptible cells and natural avian and porcine cells, which could be inhibited by the antibody against APN or anti-PDCoV-S1. APN knockdown by siRNA or knockout by CRISPR/Cas9 in chicken or swine cell lines significantly or almost completely blocked infection of these pseudoviruses. Hence, we demonstrate that HKU11, HKU13, and HKU17 with divergent S genes likely engage chAPN or pAPN to enter the cells, suggesting a potential interspecies transmission from wild birds to poultry and from birds to mammals by certain avian DCoVs. IMPORTANCE The receptor usage of avian deltacoronaviruses (DCoVs) has not been investigated thus far, though porcine deltacoronavirus (PDCoV) has been shown to utilize aminopeptidase N (APN) as a cell receptor. We report here that chicken or porcine APN also mediates cellular entry by three avian DCoV (HKU11, HKU13, and HKU17) spike pseudoviruses, and the S1 subunit of three avian DCoVs binds to APN in vitro and in the surface of avian and porcine cells. The results fill the gaps in knowledge about the avian DCoV receptor and elucidate important insights for the monitoring and prevention of potential interspecies transmission of certain avian DCoVs. In view of the diversity of DCoVs, whether this coronavirus genus will cause novel virus to emerge in other mammals from birds, are worthy of further surveillance and investigation.

Bromoacetic acid causes oxidative stress and uric acid metabolism dysfunction via disturbing mitochondrial function and Nrf2 pathway in chicken kidney.

Since the outbreak of COVID-19, widespread utilization of disinfectants has led to a tremendous increase in the generation of disinfection byproducts worldwide. Bromoacetic acid (BAA), one of the common disinfection byproducts in the environment, has triggered public concern because of its adverse effects on urinary system in mammals. Nevertheless, the BAA-induced nephrotoxicity and potential mechanism in birds still remains obscure. According to the detected content in the Taihu Lake Basin, the model of BAA exposure in chicken was established at doses of 0, 3, 300, 3000 µg/L for 4 weeks. Our results indicated that BAA exposure caused kidney swelling and structural disarrangement. BAA led to disorder in renal function (CRE, BUN, UA) and increased apoptosis (Bax, Bcl-2, caspase3). BAA suppressed the expression of mitochondrial biogenesis genes (PGC-1α, Nrf1, TFAM) and OXPHOS complex I genes (ND1, ND2, ND3, ND4, ND4L, ND5, ND6). Subsequently, BAA destroyed the expression of Nrf2 antioxidant reaction genes (Nrf2, Keap1, HO-1, NQO1, GCLM, GCLC). Furthermore, renal oxidative damage led to disorder in uric acid metabolism genes (Mrp2, Mrp4, Bcrp, OAT1, OAT2, OAT3) and exacerbated destruction in renal function. Overall, our study provided insights into the potential mechanism of BAA-induced nephrotoxicity, which were important for the clinical monitoring and prevention of BAA.

Purification of Emu IgY for Therapeutic and Diagnostic Use Based on Monoclonal Secondary Antibodies Specific to Emu IgY.

The emu is the second largest ratite; thus, their sera and egg yolks, obtained after immunization, could provide therapeutic and diagnostically important immunoglobulins with improved production efficiency. Reliable purification tools are required to establish a pipeline for supplying practical emu-derived antibodies, the majority of which belongs to the immunoglobulin Y (IgY) class. Therefore, we generated a monoclonal secondary antibody specific to emu IgY. Initially, we immunized an emu with bovine serum albumin multiply haptenized with 2,4-dinitrophenyl (DNP) groups. Polyclonal emu anti-DNP antibodies were partially purified using conventional precipitation method and used as antigen for immunizing a BALB/c mouse. Splenocytes were fused with myeloma cells and a hybridoma clone secreting a desirable secondary antibody (mAb#2-16) was established. The secondary antibody bound specifically to emu-derived IgY, distinguishing IgYs from chicken, duck, ostrich, quail, and turkey, as well as human IgGs. Affinity columns immobilizing the mAb#2-16 antibodies enabled purification of emu IgY fractions from sera and egg yolks via simple protocols, with which we succeeded in producing IgYs specific to the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) spike protein with a practical binding ability. We expect that the presented purification method, and the secondary antibody produced in this study, will facilitate the utilization of emus as a novel source of therapeutic and diagnostic antibodies.

Zinc source modulates zootechnical characteristics, intestinal features, humoral response, and paraoxonase (PON1) activity in broilers.

The current experiment was performed to find the potential effect of inorganic and organic forms of zinc (Zn) on growth, intestinal histomorphology, immune response, and paraoxonase (PON1) activity in broiler. In this experiment, a total of 450 broiler chickens were assigned to four experimental and control groups. The birds received organic Zn at the rate of 50 mg/kg (OZ-50) and 60 mg/kg (OZ-60) or inorganic Zn at the rate of 50 mg/kg (IZ-50) and 60 mg/kg (IZ-60) for an experimental period of 30 days. Significantly (P < 0.05) higher feed consumption, body weight, feed conversion ratio, and production efficiency factor (PEF) were recorded in OZ-50. Similarly, antibody titer against infectious bronchitis (IB) and PON1 activity was higher (P < 0.05) in OZ-50 compared with the control group. In addition, significantly (P < 0.05) higher villus dimensions and goblet cell count were recorded for the group OZ-50 compared with other treatments. It was concluded that the organic form of Zn was superior in improving the growth, histological features of intestines, humoral response, and PON1 activity in broiler.