Role of genetics in eleven of the most common autoimmune diseases in the post genome-wide association studies era.

Autoimmune diseases (ADs) are common conditions in which an individual's immune system reacts against its healthy cells. This condition is a common cause of morbidity and mortality, with an estimated prevalence ranging from 5 per 100,000 to more than 500 per 100,000. According to the National Stem Cell Foundation (NSCF), ADs are prevalent in about 4% of the world's population, which creates a burden on society due to the high treatment cost. ADs show a clear gender bias with a higher prevalence among women, occurring at a rate of 2:1 female-to-male ratio. The etiology of ADs includes genetic and environmental factors. ADs are more likely to develop in genetically susceptible individuals. The higher concordance ratio between monozygotic twins compared to dizygotic twins or other siblings validates the role of genetic factors in the pathogenesis of many ADs. ADs diagnosis includes conventional immunoassay such as indirect immunofluorescence, complement fixation, passive agglutination, autoantibodies detection, and most recent advances, including multiplex platforms such as microspots, line-blot, addressable microbeads and barcoded nanoparticles that allow multiplex parallel testing of autoantibodies. ADs treatment includes biological and synthetic drugs that block many pathways and components of the immune system, including Janus kinase (JAK) inhibitors, non-receptor tyrosine-protein kinase (TYK2), and other cytokines. Generally, recent immune-modulatory drugs used in ADs treatment are non-disease specific with broad action and are associated with many side effects like infection and malignant diseases. Furthermore, gene therapy seeks to control the levels of proinflammatory cytokine molecules and lymphocyte infiltration through the delivery and expression of therapeutic genes. Recent genomic-wide association studies (GWAS) have allowed the identification of various genetic loci associated with disease susceptibility and have revealed candidate genes that can be used in targeted therapeutics. This review summarizes recent literature on the genetic factors associated with susceptibility to the 11 most common ADs, namely: Type 1 diabetes mellitus (T1DM), Multiple sclerosis (MS), Grave's disease, Sjögren's syndrome (SS), Celiac disease, Hashimoto's thyroiditis (HT), Anti-phospholipid syndrome (APS), Autoimmune hemolytic anemia, Rheumatoid arthritis (RA), Systemic lupus erythematosus (SLE), and Scleroderma (systemic sclerosis).

The high susceptibility of turkeys to influenza viruses of different origins implies their importance as potential intermediate hosts.

Several previous reports and our studies show that waterfowl-origin influenza viruses can be more easily transmitted to domestic turkeys than chickens. Similarly, studies indicate turkeys to be better hosts for low pathogenic avian influenza viruses isolated from commercial poultry operations and live bird markets in comparison to chickens. Low 50% infectious-dose titers of wild bird as well as poultry-adapted viruses for turkeys further suggest that turkeys can be easily infected following a low-dose exposure. Also, interspecies transmission of swine influenza viruses to turkeys occurs frequently. These findings suggest the role of turkeys as suitable intermediate hosts that can be easily infected with influenza viruses of different origins and that turkeys can act as source of infection for other land-based poultry or even mammals.

Characterization of triple reassortant H1N1 influenza A viruses from swine in Ohio.

An H1N1 influenza A virus, A/swine/Ohio/24366/07, was isolated from pigs in an Ohio county fair. Twenty-six people who came in contact with the infected pigs developed respiratory disease and two of these people were laboratory confirmed as H1N1 by the Centers for Disease Control and Prevention (CDC). The A/swine/Ohio/24366/07 virus we isolated from swine was shown at the CDC to have 100% identical genome sequence to the human virus associated with the county fair. This prompted us to characterize three swine and two human origin H1N1 influenza A viruses isolated at different time points in the State of Ohio. The three swine viruses were shown to be triple reassortant viruses harboring genes of human (PB1), swine (HA, NA, NP, M, and NS), and avian (PB2 and PA) lineage viruses. Although viruses evaluated in this study were isolated during a short time interval (3 years), genetic drift was observed within the HA and NA genes, including changes at the receptor binding and antigenic sites of HA1 protein. Nevertheless, all viruses exhibited antigenic similarity as evaluated with hemagglutination inhibition and virus neutralizing tests. Internal genes were similar to other reassortant viruses of various subtypes currently circulating in the United States. Interestingly, two of the swine viruses including the 2007 isolate replicated well in human airway epithelial cells, however, another virus isolated in 2006 showed very little replication.

Pathobiology of triple reassortant H3N2 influenza viruses in breeder turkeys and its potential implication for vaccine studies in turkeys.

Triple reassortant (TR) H3N2 influenza viruses have been isolated from turkeys in the United States since 2003. These TR H3N2 virus infections have been associated with drastic declines in egg production in breeder turkeys although co-infection with multiple agents could have been responsible for exacerbating the clinical signs. In this study, we experimentally confirmed that TR H3N2 influenza virus alone can cause drastic reduction/complete cessation of egg production and pathology of the reproductive tract in 26-week-old breeder turkeys. We confirmed high levels of virus replication and abundant distribution of avian specific alpha2,3 sialic acid-galactose receptors in the oviduct of these turkeys. Although 2-6-week-old turkeys are routinely used for pathogenicity and vaccine protection studies, the low levels of viral shedding and asymptomatic infections in this age group often pose difficulty in interpretation of results. Our study shows that breeder turkeys should be used to assess the potential pathogenicity of TR H3N2 viruses and the viral titers and pathology of the oviduct as well as egg production data can be good measures of protection following in vivo challenge in vaccine efficacy studies.

Genetic and antigenic relatedness of H3 subtype influenza A viruses isolated from avian and mammalian species.

In 2004, we isolated triple reassortant H3N2 influenza viruses from turkey breeder hens in Ohio and Illinois. The Illinois flock was vaccinated twice with an inactivated H3N2 vaccine containing a swine origin virus before the outbreak. Additionally, a commercial inactivated vaccine containing an H3N4 virus of duck origin is being used in some turkey breeders. This prompted us to initiate a comparative study on the antigenic and genetic relatedness of various H3 subtype influenza viruses isolated from turkeys, ducks, pigs and humans. The antigenic relatedness between the different viruses was evaluated with the Archetti and Horsfall formula, while nucleotide genetic similarities were calculated using pairwise alignments. Results obtained indicated a high degree of antigenic (>90%) and genetic (>99%) similarities among the turkey-origin H3N2 viruses. However, the turkey viruses were antigenically distantly related to the swine-origin vaccine virus (<30%), although they had approximately 95% genetic similarity in the HA1 gene. Additionally, major genetic and antigenic changes were observed between the turkey viruses and the H3N4 duck vaccine virus as well as the H3N2 human virus. Such genetic and antigenic differences between the turkey-origin viruses and other H3 subtype viruses including vaccine strains could be the reason for the failure in protection in the Illinois turkey breeders vaccinated with swine origin virus. This also emphasizes the importance of using viruses for vaccines that are antigenically similar to the field strains.