Pathophysiology of the pancreas after oral infection of genetically diverse mice with coxsackievirus B4-E2.

Coxsackievirus B4 strain E2 (CVB4-E2) and its association with type 1 diabetes (T1D) have been studied in experimental in vitro and in vivo murine models. CVB4-E2, known to be pancreotropic and diabetogenic in nature, is associated with acute pancreatitis in mice but shows differences in the induction of glycemia after intraperitoneal (i.p.) infection. Therefore, the aim of this work was to study the outcome of oral infection with CVB4-E2 in five mouse strains with different genetic backgrounds: two outbred (Swiss albino, CD1), two inbred (SJL, NOD) and one transgenic (NOD.SCID). Survival rates, fasting blood glucose, histopathology, viral titres and persistence were studied in selected organs and stool samples. Viral protein (VP1), proinflammatory cytokines, and interferon alpha (IFN-α) were analyzed by immunohistochemistry. We observed mortality only in infected NOD and NOD.SCID mice, with differing survival rates implying initial innate protection in the NOD.SCID mice and low virus clearance with replicating virus titres in the studied organs and stool up to day 40 post infection (p.i.). Independent of the mouse strain hyperglycemia, proinflammatory cytokines and histopathological changes were absent in the endocrine pancreas of infected mice. Only the pancreata of the dead NOD.SCID mice showed inflammation even in presence of IFN-α. Host-dependent viral RNA persistence was observed in all outbred mice. In conclusion, oral infection with CVB4-E2, despite the known affinity of this strain towards the pancreatic tissue and the presence of replicating virus, conferred total protection to the endocrine pancreas in all mice and failed to induce the proinflammatory cytokines studied by us.

Similarities and distinctions in Y chromosome gene pool of Western Slavs.

Analysis of Y chromosome Y-STRs has proven to be a useful tool in the field of population genetics, especially in the case of closely related populations. We collected DNA samples from 169 males of Czech origin, 80 males of Slovakian origin, and 142 males dwelling Northern Poland. We performed Y-STR analysis of 12 loci in the samples collected (PowerPlex Y system from Promega) and compared the Y chromosome haplotype frequencies between the populations investigated. Also, we used Y-STR data available from the literature for comparison purposes. We observed significant differences between Y chromosome pools of Czechs and Slovaks compared to other Slavic and European populations. At the same time we were able to point to a specific group of Y-STR haplotypes belonging to an R1a haplogroup that seems to be shared by Slavic populations dwelling in Central Europe. The observed Y chromosome diversity may be explained by taking into consideration archeological and historical data regarding early Slav migrations.

Pancreas of coxsackievirus-infected dams and their challenged pups: A complex issue.

Enteroviral infections are frequent, often asymptomatic in humans and during gravidity. The present study is an extension of our previous investigations where we had shown pancreatitis in challenged pups of CVB4-E2-infected dams. Present investigation describes the effect of gestational infection with this virus on the pancreas of both dams and their challenged pups. Gravid CD1 outbred mice were orally infected with CVB4-E2 virus at different gestation times. Pups were challenged orally with the same virus after 25 days of birth. Organs were collected at selected intervals postinfection (p.i.), and replicating virus and viral-RNA copies were analyzed. Additional readouts included histopathology and immunohistochemical (IHC) analysis for localization and identification of Ly6G+ cells (neutrophils), CD11b+ cells (macrophages), and viral protein in pancreatic tissue sections of the infected dams and their challenged pups. Our results show the presence of replicating virus in the pancreas of infected dams and their challenged pups, with inflammation leading to chronic necrotizing pancreatitis and atrophy of pancreatic acini of the dams and their offspring. IHC analysis of the infiltrating cells showed pronounced Ly6G+ neutrophils in dams only, whereas CD11b+ macrophages were present in tissues of both, the pups and the dams. Time of infection during gravidity as well as the p.i. intervals when mice were sacrificed influenced the pancreatic pathophysiology in both groups. We conclude that coxsackievirus infection during pregnancy is a risk factor for chronic affliction of the exocrine tissue and could affect endocrine pancreas in the mother and child.

Expression of proliferation and apoptotic markers in human placenta during pregnancy.

Trophoblast has unique properties in relation to its wide range of metabolic, endocrine and angiogenic functions. Trophoblastic cells invade endometrium and adjacent myometrium in a way that is imitated by malignant tumours. The aim of the present study was to analyse the expression of markers of proliferation and apoptosis in trophoblastic cells in normal human placenta during pregnancy. A total of 22 placentas, 12 of which were obtained from curettage and induced legal abortion and 10 placentas obtained from normal deliveries or caesarean sections were included in this study. Proliferation markers were strongly expressed in cytotrophoblast in early stages of gestation. In late term placentas, a distinct decrease in expression of these markers was observed. Syncytiotrophoblast was negative for proliferation markers in all placentas. Positive immunostaining for bcl-2, an anti-apoptotic marker, was observed only in syncytiotrophoblastic cells in first-trimester but also in third-trimester placentas. Cytotrophoblast and stromal mesenchymal cells of chorionic villi were negative for bcl-2. Expression of bcl-2 protein in syncytiotrophoblast may be one of the major factors preventing these structures from early cell death, which is indispensable for the maintenance of physiological pregnancy.

Outcome of challenge with Coxsackievirus B4 in young mice after maternal infection with the same virus during gestation.

Enteroviral infections go usually unnoticed, even during pregnancy, yet some case histories and mouse experiments indicate that these viruses may be transmitted vertically. More frequently, however, transmission occurs by (fecal) contamination during and shortly after birth. The aim of this study was to investigate the effect of maternal infection in mice (1) on gravidity outcome and (2) on subsequent challenge of the offspring with the same virus. CD1 outbred female mice were infected by the oral route with coxsackievirus B4 strain E2 or mock-infected at days 4, 10, or 17 of gestation. Weight and signs of sickness were noted daily. Pups were infected at day 25 after birth (4 days postweaning). Organs (brain, pancreas, and heart) were analyzed for viral RNA and histopathology. We observed that maternal infection at day 4 or day 17 of gestation had little effect on pregnancy outcome, whereas infection at day 10 affected dams and/or offspring. Infection of pups resulted in severe inflammation of the pancreas, but only when dams were previously infected, especially at day 17. The blood glucose levels were elevated. Because no trace of infection was found at the time of challenge, a role for immunopathology is suggested.

Coxsackie B virus infection of mice: inoculation by the oral route protects the pancreas from damage, but not from infection.

The pathogenesis of coxsackie B virus (CVB) infections is generally studied in mice by intraperitoneal (i.p.) injection, whereas the gastrointestinal tract is the natural porte d'entrée in humans. The present study was undertaken to compare systematically the influence of infection route on morbidity and pathology. Swiss Albino mice were infected with CVB3 (Nancy) at different doses (5 x 10(3), 5 x 10(5), 5 x 10(7), 5 x 10(9) TCID50), given either i.p. or orally. Virus could be isolated from several organs (heart, spleen and pancreas), indicating systemic infection, irrespective of the infection route. Virus titres were 1-2 logs higher after i.p. infection, but kinetics were largely independent of infection route. Organs became negative for virus isolation after 21 days, with the exception of spleen tissue, which remained positive for up to 49 days. Thereafter, virus was detected only by immunohistochemistry and PCR up to 98 days post-infection (oral route). Histopathology showed mild inflammation and necrosis in heart tissue of all mice during the acute phase, with repair at later stages. Strikingly, pancreatic lesions were confined to the exocrine pancreas and observed only after i.p. infection. Under all experimental conditions, the pancreatic islets were spared. In contrast, immunohistochemistry showed the presence of viral VP1, protein 3A and alpha interferon (IFN-alpha) in exocrine as well as endocrine pancreas of all mice, irrespective of route and dose of infection. It is concluded that infection via the oral route protects the pancreas from damage, but not from infection, a process in which IFN-alpha is not the only factor involved.