the Vector? 
There have been several studies to evaluate whether replication competent 
adenovirus administered to the human respiratory tract (usually nasal) will 
result in anti -adenovirus antibodies (see Table 5.2-A in section 5). Howev- 
er, although anti -adenovirus antibodies may develop, experimental animal 
studies suggest the respiratory route is not a very effective route to 
achieve immunization against recombinant proteins. For example, recent 
studies by B. Murphy (NIAID, personal communication) in rhesus showed that 
intratracheal administration of 10 8 TCID 50 of a recombinant replication 
competent adenovirus containing the exogenous respiratory syncytial virus 
(RSV) F protein gene in the E3 position elicited significant anti-adenovi- 
rus antibodies in blood, but not anti-RSV-F protein antibodies in lung. 
Consistent with studies of adenovirus administration to humans, studies in 
cotton rats receiving intratracheal Ad-CFTR elicited anti -adenovirus anti- 
bodies in serum (Figure 4.5-A). By day 7, anti-Ad-CFTR antibodies were 
readily detectable in serum and remained detectable for at least 4 months. 
Similar studies have been carried out to evaluate serum anti -adenovirus 
antibodies associated with a single respiratory tract administration of 
AvlCFl compared to Ad5 (Figure 4.5-B). The pattern of anti -adenovirus 
antibodies elicited in serum was similar to that observed with respiratory 
administration of AdCFTR (Figure 4.5-A). 
To determine the antibody response to an adenovirus type 5 -based replica- 
tion deficient adenovirus vector in non-human primates, a recombinant 
adenovirus containing the E. coli lacZ gene (AdRSV . /9gal) was administered 
to the large airways of rhesus monkeys (rhesus study 1C and 2C) . Two con- 
trols (receiving vehicle) and 4 adenovirus vector treated animals were 
evaluated. Adenovirus was delivered to the right mains tem bronchus at days 
0 and then again at days 21 or 28. Animals were serially evaluated at day 
3, then weekly for one month, then bi-weekly, then monthly, for up to 187 
days. Serum antibody to adenovirus type 5 was assayed by serum neutraliza- 
tion of adenovirus type 5 using A549 cells. Control animals (receiving 
vehicle) did not have an increase in serum neutralization titers. Treated 
animals had the following responses: one of four animals had a marked rise 
in titer from <1:10 to 1:40 after 14 days; one animal did not have a rise 
in serum titers until after a second dose of AdRSV. /3gal; the remaining two 
animals did not have any elevation of titer throughout the study period. 
All titers fell to 1:10 or lower 35 days after the second dose except in 
one animal in which the titer remained elevated at 1:80 at day 124. In 
group 3C, the control had no increase in neutralizing titer over baseline; 
in the 2 treated animals, 1 had no increase, and the other had a sustained 
increased titer of 1:10. 
Similar to studies evaluating the antibody response to AdRSV. /9gal, the 
serum neutralization titers were determined after AvlCFl (10 10 pfu/kg) was 
administered to the large airways of rhesus monkeys (rhesus studies 4C and 
5C) . In rhesus study 4C , vehicle (n=l) or AvlCFl (n=2) was delivered to the 
right mainstem bronchus at day zero. Animals were evaluated weekly for 42 
days, then biweekly, for up to 83 days for serum neutralization titers. The 
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