Abstracts Vol. 1 [International Conference on AIDS (11th: 1996: Vancouver, Canada)]

Tu.A.2078 - Tu.A.2084

Tuesday July 9, 1996

region of the LTR; breakpoints in pol and vif were also observed. Some of the recombinant
virior would be predicted to possess the matrix and core of one clade and the outer
envelope of another resembling virus pseudotypes.These and other mosaic virion structures are suggestive of altered cell tropism as a selective force fostering the emergence of
recombinant forms.
Conclusion: The biological properties of recombinant HIV-I strains should be the subject of
rigorous i nvestigation, as these exchanges of genetic material may represent a common
adaptive strategy with significant functional and epidemiologica iimplcations.
FE McCutchian, 1600 East Gude Drive, Rockville, MD 20850 USA Telephone: [phone]
Fax [phone] ermail: fmccutchan)hiv.hjforg
Tu.A.2078
DETECTION OF PHYLOGENETICALLY LINKED HIV STRAINS AMONG A
POPULATION OF EPIDEMIOLOGICALLY UNRELATED WOMEN
Kalish, Marcia L.1, Wiener p I, Nesheim S2, Lee F2, Meadows L2, Grimes V2, Sawyer M2,
Baldwin A, Rapier J, Simonds RJ, Schochetman G I, Nahmias A2. Centers for Disease
Control and PreventionI and Grady Hospital2, Atlanta, GA.
Objectives: To characterize the extent of genetic variation in a large population of babies
born to high risk, HIV positive mothers.
Methods: A sampling of 94 HIV positive babies, born to HIV- infected mothers enrolled in a
perinatal transmission study were selected for study DNA were amplifed using a nested
PCR, and 345 nucleotides, spanning the C2-V3 region, were sequenced directly from their
PCR product. Sequences were analyzed using the Neighbor-joining program of PHYLIP
Results: Several groups of baby HIV sequences were found to be phylogenetically related.
One pair of related sequences represented two infected siblings, born approximately one
year apart. In spite of a 7.6% difference in the HIV strains infecting the two babies, there
was 100% bootstrap support for their genetic relatedness. In another cluster often phylogenetically related HIV strains among epidemiologically unrelated babies, there was a strong
statistical correlation (p=0.001) between the mothers being injecting drug users and their
HIV strains being genetically related. Furthermore, even within this background of closely
related sequences, maternal- infant sequences grouped together with bootstap supports
of>93%.
Conclusion: In previous reports of inter person variation among HIV subtype B strains
from random, epidemiologically unrelated persons in the United States, no structure to the
phylogenetic trees has been observed.The likely explanation of this large clustering of HIV
strains is the identification of a social network" linked indirectly through injecting drug use.
Dr Marcia L. Kalish CDC, Mailstop D- 12, 1600 Clifton Rd. Atlanta GA 30333 USA
Telephone:[phone] FAX:[phone] E-mail: [email protected] gov
Tu.A.2080
CD4+ CELL INFLECTION AND HIV HETEROGENEITY
Raj Shankarappa, Phalguni Gupta2, Charles R. Rinaldo, Jr.2,Joe Margolick3, James I. Mullinsl.
Universrty of Washington, Seattle, University of Pittsburgh and Johns Hopkins University3.
Objective: Following infection with HIV I, some infected individuals exhibit long periods of
stable CD4+ T lymphocyte cell levels followed by an inflection and rapid decline.These individuals represent an important group for study of virus host interactions since the balance
changes from a relatively stable standoff one to one in which the host is no longer able to
contain the virus. We are addressing the hypothesis that such shift is associated with evolution and outgrowth of viral variants with increased virulence.
Methods: HIV I infected individuals fiom the Multicenter AIDS Cohort Study (MACS), have
been selected for the prospective analysis of viral variation. Sequences representingV3-V5
domains of the env have been amplified by PCR and used in heteroduplex mobility assay
for assessing the nature o' variants, and in heteroduplex tracking assay for assessing the viral
variant turnover, and for DNA sequencing.
Results: In the three patients examine d so fr sequences present in the early time point
appear to be homogeneous. In the two patients exhibiting pronounced inflection in the
CD4+ T lymphocyte decline, unique variant clusters could be seen to predom nate before
and after inflection. In con tr ast, in the one patient exhibiting a shoh rt period of stable CD4+
cell levels prior to a rapid decline appear to show less overall variability and a long term
persistence of the initial variant populations.
Conclusions: Time periods corres ponding to marked decline in the CD4+ cell numbers
appear to be associated with the evolution and/or outgrowth of variants divergent from the
earlier quasispecies populations.
Raj Shankarappa, Box 357740, Univ ofWashington School of Medicine, Room K463, Health
Sciences Building, Dept of Microbiology, Seattle WA98 195 7740
Tu.A.208 I
MEXICAN HIV-I V3 LOOP SEQUENCES GROUPED ACCORDING TO ROUTE OF
TRANSMISSION.
Soto- Ramirez Luis E. 1,2, Renifo B.2, Marhnk Richard-, Max Essex2. 1Instituto Nacional
Nutncion, Mexico DFMEXICO; 2Harcard School of Public Health, Boston, MA, USA.
While most of the AIDS cases in Mexico are related to homosexual transmission of HIV- I,
an increased nuraber of cases in women are attributed to heterosexual transmission.
Despite reports of non-B HIV-I subtypes in Central America related to heterosexual transmission, subtyping of HIV viruses has not been described in Mexico. Our objective was to
sequence the V3 loop of Mexican HIV isolates, group them phylogenetically and compare
them to atheor knownr DIV subtypes.
Methods: 8 himosexal sues, 3 heterosexually infected females and I heterosexually
promiscuous male with more than 200 CD4+ cells were analyzed. Proviral DNA was
ampliFed using PCR with speciic primers that encompass the V3 loop of the gpI20.Three
clones of each individual were sequenced and the deducted consensus aminoacd
sequences were compared between them and with consensus sequences of the principal
DIV-I sultypes in 5a ivr'~s manner
Results: le crown ofV3 was predominanty GPGQ (8 cases) followed by GPGR (3), and
GPGK () Phylgenetic ainays s of the sequeces showed that samples from heterosexually rhoected females grociped tayether-red wore related to sequences of a heterosexual
masle, but cearly separated frcm the sounces frem homosexual oubjects.The sequeces

from the three heterosexual females grouped with the consensus sequence of subtype [D
viruses while the homosexual males grouped with subtype B.
Conclusions: I.-V3 loop sequences from Mexican HIV I isolates grouped ccor, to
mode of transmission of the virus, which suggest selection dunrng tras sron. 2. olate,
from heterosexually infected woman grouped phylogenetically closer to Afr can subtypes
where heterosexual transmission is significant. 3.-These findings would upport the Ipoh
esis of strain adaptation to route of transmission.
Richard Marlink, M.D. Department of Cancer Biology Harvard School of Pubic He, F,65_
Huntington Ave. Bldg. I, Room 903. Boston, MA. 021 15. USA. Phone: (6 7) 432 - Fx
[phone]
Tu.A.2082
HIV-I SEROTYPING AMONG A COHORT OF INDIVIDUALS FROM SAO PAULO
CITY, BRAZIL
Casseb, lorge*#, Hong, M**, Gonsalez, C.**, Duarte, A.**, Hendry R.M# *Instituto dein
Infectologia Emilio Ribas,SRBrazil; # Viral and Rickettsial Disease Laboratory, Caliform n iDept.
of Health Services, Berkeley CA, USA; **Laboratorio de Imunogenet ica da Facu udide de
Medicina da Univ. Sao Paulo, SP Brazil
Objective: Brazil has reported the fourth highest number of AIDS cases n the world. Sao
Paulo State represents 56% of all cases reported over 15 years.There are at least three different HIV I subtypes co-circulating in Brazil (B, F and C), with subtype B predoninatr
Recently it was reported that two genetically and antigenically distinct strainf of subtype B
co-circulate in Brazil. One strain has the GPGR motif in the in the tetrapeptide tip o the Vi
region similar to US/European isolates whereas the other has a GWGR motif thait s unique
to Brazil.We therefore analyzed the distribution of the two subtype B strains with regard to
clinical status, modes of transmission and gender.
Methods:We used 19 AAV3 biontinyled peptides representin g consensus B, C, F, MN, SF2
and two consensus containing the GWGR motif in a modified EIA Pept des wer e cptured
onto avidin-coated plates and two serum titrations were performed with each peptide.
One titration was washed with PBS-Tween 20, the other with PBS Tween--8 M ureito
remove low avidity antibodies.The endpoint titers were computed from the inear region of
the titration curve (O.D.=0.5) and an avidity index (AI) was computed from the
formula:(urea titer/PBS titer) x 100.A typing algorithm based on titer ratios early d iscrmnated the sera into 2 groups. A cross sectional study was performed amon g patients fom
the Immunology Division of the Hospital das Clinicas, Univ. Sao Paulo. I he subjects were
classified in accordance to CDC AIDS Classification, revised in 1993.
Results: All sera were typed as subtype B.The strain distribution is shown i n the table.
Clinical Status Transmission Gender
STRAIN AIDS ASYMP. HOM/BI HETER IDU Male Female
GPGR 19 18 28 10 1
GWGR 24 20 34 4 05.
TOTAL 43 38 62 24 06 r 1
Conclusions:The GPGR and GWGR strains showed a similar distrbution with regard to
clinical status, modes of transmission and gender.V3 serology is an e'asy and inexpensive
method to distinguish subtype B strains in Brazil. Expanded longitudinal studies wi lbe need
ed to define differences between the two strains in disease progress on.
Jorge Casseb,Viral and Rickettsial Disease Laboratory 2 15 Berkeley Way, Room 3
Berkeley CA, USA, 94703;Tel:[phone]; Fax: [phone]
Tu.A.2083
BCG AND ANTI-TETANUS VACCINATIONS INDUCE A TRANSIENT INCREASE OF
VIRAL LOAD AND env GENE VARIABILITY IN HIV-2 INFECTED MACAQUES
Bi.yon-Auboyer Marie-Helene, Boussin F-D., Le Grand R.,,Brm cCGDorin ritb). EA,
DRM, SSA, Fontenay-aux-Roses, France
Objective: To investigate the vir ological onsequences of a nonspe fic snulaton o the
immune system in healthy but persistently HIV-2-infected nacaque<
Method: Four- macaques were involved in this studyThey have ber infcted by HIV
SBL6669/H5 for more than 4 years, and they had a low viral load in them rer pher lblood.
Three of them were previously vaccinated with 0. 1 ml of a non recomIrint B( (Paster
France).The four monkeys received intramusculary 0.5 ml of Tetiavax wtviccnre Institut
Merieux, France) 15 days later.Two boosters ofTetavax vaccine were rde with in tervl
of 28 days. Monkeys were monitored for viral isolation, by semi- qu,nit atie PCR perfomed
on DNA extracted from uncultured PBMC, and by antibody titer detei mirtion The V3 to
V5 region of the env gene was directly sequenced fiom PCR prodts.
Results: After the vaccinations, we observed a transient increase of the v, load n pe ipheral blood of all the monkeys as demonstrated by PCR and viral iolton rssay hree of
the monkeys evidenced a transient peak of their anti-HIV 2 antibody titer. urthermore a
elevated number of mutations was observed in proviral DNA detected in the PBMC.t i em
was a correlation between viral isolation, antibody titers and dyna ri I n taoi e entre
Conclusion: These results evidence an enhancement of viral rephcat on ind evrne' c mm
ability by the vaccinations.The persistence of some mutations suggests ti it t n laton
the immune system of a infected individual may have Iongterm consequences Ths e
be further investigated.
Bayon Auboyer Marie-Hilene: 60-68, avenue de la division Leclerc, BP6, 92 26_ Fomter
aux-Roses, FranceTEL: (33- I) 46-54-87-38
Tu.A.2084
THE CHARACTERIZATION OF THE PARTIAL ENV GENE OF HIV- I ISOLATED FROM
KOREAN
bee, Kang, C., Lee, H.R., Nam, J.G., Kim, S.H., Cho, YS., Maeng, S.H. Shn,YO Ca te
AIDS Research, Department of virology NIH, Seoul, Krea
Objective: Molecular epidemiology of AIDS is a hut isse becase cmo inui ii equecn ce i
can be used to complement epidemiologic refer mition in ti icn iss n stus, nO tc deo
lope an effective vaccine against DIV.

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