In Ovo Vaccination with Recombinant Herpes Virus of the Turkey-Laryngotracheitis Vaccine Adjuvanted with CpG-Oligonucleotide Provides Protection against a Viral Challenge in Broiler Chickens.

Infectious laryngotracheitis (ILT) is an economically important disease in chickens. We previously showed that an in ovo adjuvantation of recombinant herpesvirus of the turkey-Laryngotracheitis (rHVT-LT) vaccine with CpG-oligonucleotides (ODN) can boost vaccine-induced responses in one-day-old broiler chickens. Here, we evaluated the protective efficacy of in ovo administered rHVT-LT + CpG-ODN vaccination against a wild-type ILT virus (ILTV) challenge at 28 days of age and assessed splenic immune gene expression as well as cellular responses. A chicken-embryo-origin (CEO)-ILT vaccine administered in water at 14 days of age was also used as a comparative control for the protection assessment. The results showed that the rHVT-LT + CpG-ODN or the CEO vaccinations provided significant protection against the ILTV challenge and that the level of protection induced by both the vaccines was statistically similar. The protected birds had a significantly upregulated expression of interferon (IFN)γ or interleukin (IL)-12 cytokine genes. Furthermore, the chickens vaccinated with the rHVT-LT + CpG-ODN or CEO vaccine had a significantly higher frequency of γδ T cells and activated CD4+ or CD8+ T cells, compared to the unvaccinated-ILTV challenge control. Collectively, our findings suggest that CpG-ODN can be used as an effective adjuvant for rHVT-LT in ovo vaccination to induce protective immunity against ILT in broiler chickens.

The role of angiotensin-converting enzyme 2 (ACE2) genetic variations in COVID-19 infection: a literature review.

Background: The angiotensin-converting enzyme-2 (ACE2) is recognized to be the fundamental receptor of severe acute respiratory syndrome coronavirus-2 (SARS-CoV2), responsible for the worldwide Coronavirus Disease-2019 (COVID-19) epidemic. However, genetic differences between people besides racial considerations and their relation to disease susceptibility are still not fully elucidated. Main body: To uncover the role of ACE2 in COVID-19 infection, we reviewed the published studies that explore the association of COVID-19 with the functional characteristics of ACE2 and its genetic variations. Notably, emerging studies tried to determine whether the ACE2 variants and/or expression could be associated with SARS-CoV/SARS-CoV2 have conflicting results. Some researchers investigated the potential of "population-specific" ACE2 genetic variations to impact the SARS-CoV2 vulnerability and suggested no ethnicity enrichment for ACE2 polymorphisms that could influence SARS-CoV2 S-protein binding. At the same time, some studies use data mining to predict several ACE2 variants that could enhance or decline susceptibility to SARS-CoV. On the other hand, fewer studies revealed an association of ACE2 expression with COVID-19 outcome reporting higher expression levels of ACE2 in East Asians. Conclusions: ACE2 gene variants and expression may modify the deleterious consequences of SARS-CoV2 to the host cells. It is worth noting that apart from the differences in gene expression and the genetic variations of ACE2, many other environmental and/or genetic factors could modify the disease outcome, including the genes for the innate and the adaptive immune response.