BACKGROUND: We previously reported that human adenovirus Ad-36 induces adip
osity and paradoxically lower levels of serum cholesterol (CHOL) and trigly
cerides (TC) in animals.
OBJECTIVE: To evaluate the transmissibility of Ad-36 and Ad-36 induced adip
osity using a chicken model.
DESIGN: Experiment 1-four chickens were housed (two per cage) and one from
each cage was inoculated with Ad-36. Duration of presence of Ad-36 DNA in t
he blood of all chickens was monitored. Experiment 2-two groups of chickens
were intranasally inoculated with Ad-36 (infected donors, I-D) or media (c
ontrol donors, C-D). Blood drawn 36 h later from I-D and CD groups was inoc
ulated into wing veins of recipient chickens (infected receivers, I-R, and
control receivers, C-R, respectively). On sacrifice, 5 weeks post-inoculati
on, blood was drawn, body weight noted and visceral fat was separated and w
eighed.
RESULTS: Experiment 1-Ad-36 DNA appeared in the blood of the inoculated chi
ckens and that of uninoculated chickens (cage mates) within 12 h of inocula
tion and the viral DNA persisted up to 25 days in the blood. Experiment 2-c
ompared with C-D, visceral and total body fat were significantly greater an
d CHOL significantly lower for the I-D and I-R. TC were significantly lower
for the I-D. Ad-36 was isolated from 12 out of 16 blood samples of the I-D
that were used for inoculating I-R chickens. Ad-36 DNA was present in the
blood and the adipose tissue of the I-D and I-R but not in the skeletal mus
cles of animals selected randomly for testing.
CONCLUSION: As seen in experiment 1, Ad-36 infection can be transmitted hor
izontally from an infected chicken to another chicken sharing the cage. Add
itionally, experiment 2 demonstrated blood-borne transmission of Ad-36-indu
ced adiposity in chickens. Transmissibility of Ad-36-induced adiposity in c
hicken model raises serious concerns about such a possibility in humans tha
t needs further investigation.