Calmodulin-like 5 promotes PEDV replication by regulating late-endosome synthesis and innate immune response.

The infection caused by porcine epidemic diarrhea virus (PEDV) is associated with high mortality in piglets worldwide. Host factors involved in the efficient replication of PEDV, however, remain largely unknown. Our recent proteomic study in the virus-host interaction network revealed a significant increase in the accumulation of CALML5 (EF-hand protein calmodulin-like 5) following PEDV infection. A further study unveiled a biphasic increase of CALML5 in 2 and 12 â€‹h after viral infection. Similar trends were observed in the intestines of piglets in the early and late stages of the PEDV challenge. Moreover, CALML5 depletion reduced PEDV mRNA and protein levels, leading to a one-order-of-magnitude decrease in virus titer. At the early stage of PEDV infection, CALML5 affected the endosomal trafficking pathway by regulating the expression of endosomal sorting complex related cellular proteins. CALML5 depletion also suppressed IFN-ß and IL-6 production in the PEDV-infected cells, thereby indicating its involvement in negatively regulating the innate immune response. Our study reveals the biological function of CALML5 in the virology field and offers new insights into the PEDV-host cell interaction.

Regulation of Tripartite Motif-Containing Proteins on Immune Response and Viral Evasion.

Tripartite motif-containing proteins (TRIMs), exhibiting ubiquitin E3 ligase activity, are involved in regulation of not only autophagy and apoptosis but also pyrotosis and antiviral immune responses of host cells. TRIMs play important roles in modulating signaling pathways of antiviral immune responses via type I interferon, NF-κB, Janus kinase/signal transducer and activator of transcription (JAK/STAT), and Nrf2. However, viruses are able to antagonize TRIM activity or evenly utilize TRIMs for viral replication. This communication presents the current understanding of TRIMs exploited by viruses to evade host immune response.

Prevalence and molecular characterization of Trichomonas gallinae from domestic pigeons in Beijing, China.

Trichomonas gallinae is a globally distributed protozoan parasite, mainly affect the upper avian digestive tract and can bring huge economic losses to pigeon industry. The objective of the present study was to determine the prevalence and genotypes of T. gallinae in Beijing, China. A total of 569 samples of throat swabs of pigeon were collected from pigeon farms in Shunyi District, Fangshan District, Daxing District and Miyun District of Beijing. The overall prevalence was 28.30%. The significant difference in infection rates was not observed between regions, but was found between age groups. The highest prevalence was nestling pigeons (33.16%), followed by adolescent pigeons (30.05%) and breeding pigeons (20.59%). Moreover, genotype A and B of T. gallinae were identified by sequencing the ITS1/5.8S/ITS2 regions and phylogenetic analysis. To our knowledge, this is the first report to display the prevalence and genotype of T. gallinae from Beijing, China.

Effects of stocking density on growth performance, meat quality and tibia development of Pekin ducks.

This study was performed to investigate the effects of stocking density on performance, meat quality and tibia development in Pekin ducks reared on a plastic wire floor. A total of 372 healthy, 21-day-old, male ducks with similar body weight (BW) were randomly allotted to stocking densities of five (low), eight (medium) and 11 (high) birds/m2 . Each group had six replicates. Results showed that compared with the low density group, medium and high stocking density caused a decrease in final BW at 42 days old, and in average daily gain, European performance index (p < .01) and meat pH at 45 min postmortem (p < .001), and an increase of meat drip loss (p < .01). High stocking density resulted in an increase of feed/gain ratio (p < .001), but a decrease of tibia calcium (p < .01) and phosphorus content (p < .05). Meat color, shear force values, tibia size (weight, length, and width) and breaking strength were not significantly influenced by stocking density. In conclusion, stocking density over eight birds/m2 negatively affects growth performance, but meat quality and tibia development are not dramatically influenced. Based on this study, the stocking density of male Pekin ducks should be adjusted between five and eight birds/m2 .