Ad-36 Antibody Research Articles

Novel short-term effects of adenovirus Ad-36 on hamster lipoproteins.

Human adenovirus Ad-36 induces adiposity and lowers total serum cholesterol in chickens, mice and marmosets and Ad-36 antibodies are associated with human obesity. We examined the early effects of Ad-36 inoculation on plasma cholesterol levels in hamsters fed a hyperlipidemic diet. A total of 32 male Golden Syrian hamsters were divided into two equal weight-matched groups and intranasally inoculated with Ad-36 (INF: infected) or media (CON: control). In each group, the animals were fed either a purified diet (PF, n=8) 40%en fat +/-194 mg cholesterol/1000 kcal or chow (C, n=8) ad libitum. Animals were killed 5 weeks postinoculation. Nested PCR assay detected Ad-36 DNA in the lung, liver, visceral adipose tissue and skeletal muscle of the INF group, but not in the CON animals. Ad-36 antibodies were detected in the INF group only. For all animals, total plasma cholesterol (TC) was not significantly affected by Ad-36 treatment (203+/-92 vs 193+/-75 mg/dl, P=NS; INF vs CON, respectively). In 5 weeks, Ad-36 infection had no effect on TC concentration in hamsters fed chow (128+/-39 vs 130+/-27 mg/dl, INF-C vs CON-C, respectively) or those fed PF (269+/-70 vs 256+/-47 mg/dl, INF-P vs CON-P, respectively). However, lipoproteins isolated by density gradient ultracentrifugation showed a greater proportion of LDL cholesterol in INF animals, as compared to CON (28.4+/-1.6% vs 16.4+/-1.2%, P=0.02), regardless of dietary treatment (INF-P vs CON-P: 27.3+/-2.1 vs 15.7+/-1.5%, P=0.07; and INF-C vs CON-C: 29.4+/-1.2 vs 17.0+/-1.1%, P=0.009). This shift appears to be from HDL cholesterol to the LDL fractions. These data suggest that in the hamster (a model resembling several aspects of human lipoprotein metabolism), Ad-36 infection may acutely affect the intravascular processing of lipoproteins resulting in a more atherogenic lipoprotein profile.

Human Adenovirus Ad-36 Promotes Weight Gain in Male Rhesus and Marmoset Monkeys

Although obesity has multiple etiologies, an overlooked possibility is an infectious origin. We previously identified two viruses, SMAM-1, an avian adenovirus (Ad), and Ad-36, a human adenovirus, that produce a syndrome of visceral obesity, with paradoxically decreased serum cholesterol and triglycerides in chickens and mice. In the two studies presented in this paper, we used nonhuman primates to investigate the adiposity-promoting potential of Ad-36. In study 1, we observed spontaneously occurring Ad-36 antibodies in 15 male rhesus monkeys, and a significant longitudinal association of positive antibody status with weight gain and plasma cholesterol lowering during the 18 mo after viral antibody appearance. In study 2, which was a randomized controlled experiment, three male marmosets inoculated with Ad-36 had a threefold body weight gain, a greater fat gain and lower serum cholesterol relative to baseline (P <0.05) than three uninfected controls at 28 wk postinoculation. These studies illustrate that the adiposity-promoting effect of Ad-36 occurs in two nonhuman primate species and demonstrates the usefulness of nonhuman primates for further evaluation of Ad-36-induced adiposity.