home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Shareware Overload Trio 2
/
Shareware Overload Trio Volume 2 (Chestnut CD-ROM).ISO
/
dir26
/
med9410p.zip
/
M94A3273.TXT
< prev
next >
Wrap
Text File
|
1994-10-25
|
3KB
|
44 lines
Document 3273
DOCN M94A3273
TI Unusual A/G ratio in HIV-1 gp120 V3 loop proviral sequences obtained in
vivo.
DT 9412
AU Gomez Carrillo M; Rabinovich R; Marquina S; Galvan V; Libonatti O; Natl.
Centre of Ref. for AIDS, Buenos Aires, Argentina.
SO Int Conf AIDS. 1994 Aug 7-12;10(1):113 (abstract no. PA0072). Unique
Identifier : AIDSLINE ICA10/94369302
AB OBJECTIVE: To analyze A/G ratio values of proviral V3 loop HIV-1
sequences and correlate them with some phenotypic features of the
corresponding variants. METHODS: After sequencing using the Sanger
method, A/G ratio values were calculated for 28 in vivo, 2 isolate
Argentine sequences and 21 published worldwide isolates. These values
were correlated with the phenotypic characteristics of the corresponding
variants. EIA assays were performed using synthetic peptides derived
from HXB2 and MN isolates sequences. The G-->A hypermutation phenomenon
was simulated for all sequences studied. RESULTS: Two distinct types of
in vivo V3 loop sequences could be distinguished: 14 presented an
unusually low A/G ratio value (lower than 2) and 14 beared
characteristics similar to the standard worldwide isolates. Unusual
sequences showed certain uncharged residues at positions 9 and 10 and a
low overall positive charge. Patients' sera corresponding to these
sequences showed higher reactivity against V3 loop peptides. Simulated
G-->A transitions originated polar and positive residues, resulting in
isolate-like charge distributions in usual sequences but not in unusual
ones, while isolates remained relatively stable. DISCUSSION AND
CONCLUSIONS: Unusual sequences might be present in patients with a
functional immune response but would not be adapted to culture
conditions. The G-->A hypermutation would occur less frequently in these
variants, and the resulting increase in antigenicity would favour their
elimination. The immune response and the G-->A hypermutation could act
as two balanced mechanisms in the generation of variants differing in
A/G contents.
DE Base Composition DNA, Viral/CHEMISTRY/*GENETICS Human HIV
Antibodies/BLOOD HIV Envelope Protein gp120/*GENETICS/IMMUNOLOGY HIV
Infections/IMMUNOLOGY/MICROBIOLOGY HIV-1/*GENETICS/IMMUNOLOGY/ISOLATION
& PURIF Mutation Peptide Fragments/*GENETICS/IMMUNOLOGY Phenotype
Proviruses/*GENETICS/IMMUNOLOGY Variation (Genetics) MEETING ABSTRACT
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).