Biology Reference
In-Depth Information
HPV16 and 6 in mice.
46
Balb/c mice were immunized nasally with the
peptide, and the sera or vaginal washes were pooled from five animals
for characterization. IgG antibodies in the sera and mucosal IgA anti-
bodies in the vaginal washes bind to L1/L2-capsids of HPVs 6, 16, and
18, and neutralize HPV16 pseudovirions and HPV11 authentic virions.
Embers
et al
.
47
further characterized antibodies against HPV16 and
HPV6 L2 distinct regions. The peptides having amino acid sequences
of HPV16 L2 aa108-120 (16L2a), HPV16 L2 aa104-124 (16L2b:
SIVSLVEETSFIDAGAPTSVP), HPV6/11 L2 aa108-120 (6/11L2a),
and HPV6/11 L2 aa104-124 (6/11L2b:IVSLIEESAIINAGAPEIVPP)
were synthesized and conjugated to keyhole limpet hemocyanin (KLH)
for immunization or to bovine serum albumin (BSA) for ELISA.
Antisera have been produced by immunizing rabbits and Balb/c mice
(two animals per one immunogen) with one of the peptides. All of the
sera react to the peptide used for immunization and show some level of
cross-reactivity to the heterologous peptides. However, the antisera do
not show significant cross-reactivity in ELISA using HPV16 and HPV11
L1/L2-capsids as antigens.
Neutralizing activities of the antisera were assessed by inhibition of
infection with authentic HPV16 (obtained from cervical legions) and
HPV11 virus (obtained from a condyloma and propagated by the use
of human foreskin xenografts into nude mice). Neutralizing activity of
the sera varied between two animals immunized with the same peptide
in spite of the animals being inbred. Two rabbit sera, one obtained by
immunization with 6/11L2a and one with 6/11L2b, have showed
significant neutralizing activities to both HPV11 and HPV16 viruses.
Rabbit antisera obtained by immunization with the HPV16 peptides
showed very little ability to neutralize the HPV11 virus. Two mouse
antisera obtained by immunization with H16L2a and one with
H16L2b showed significant neutralizing activities to both HPV11 and
HPV16 viruses. The H6/11L2a peptide was the poorest immuno-
gen in mice for the production of neutralizing antibodies. The data
support evidence that the epitope(s) in the L2 region containing
aa108-120 may yield antibodies capable of neutralizing infectivity
across viral types. The reason why the immunoreactions of the rabbits
or mice vary with the individual rabbit or mouse is not clear.
