Abstract Book Vol. 2 [International Conference on AIDS (14th: 2002: Barcelona, Spain)]

XIV International AIDS Conference

Abstracts WePeA5776-WePeA5779 21

chemokine receptor and SDF-1 gene polymorphisms, and levels of PBMCassociated TREC.
Results: After 5 years, 24 out of 47 individuals became late progressors (LP)
since they had loss CD4+ T cells below 500 cells/Rl and/or have initiated antiviral
treatments. By univariate analysis, both low CD4+ T cell counts and viremia were
significantly associated with evolution from LTNP to LP (p = 0.0008 and 0.0011,
respectively). Lack of HIV isolation at entry was correlated to maintenance of the
LTNP condition (p = 0.0007). Isolation of SI viruses was associated with LP (p
= 0.0001). No significant differences between the two groups were observed in
terms of their genetic background involving CCR5, CCR2 and SDF-1 allelic variants. PBMC-associated sjTRECs decreased in individuals who remained LTNP
during the 5 years of observation although no significant variations of CD4+ T
cell number, viremia and PBMC-associated HIV DNA were seen in this population. After 7 years of follow-up, only 14 out of the original 47 individuals remained
LTNP. These individuals have high CD4+ T cells count(median: 1,019 cells/Il,
range: 510-1,672),whereas plasma viremia remains undetectable in 6/14 individuals (median: 945, range: 50-15,900 copies/ml). The remainder parameters are
currently been evaluated.
Conclusions: In addition to viremia and CD4+ T cell counts,viral phenotype and
positive HIV isolation are predictors of disease evolution from the LTNP condition. The decreased TREC levels in LTNP suggests that loss of T cell renewal
may represent an early marker of disease progression in these individuals.
Presenting author: Silvia Ghezzi, San Raffaele Scientific Institute, Italy, Tel.: +39
0226434902, Fax: [phone], E-mail: [email protected]
WePeA5776 1HIV-1 neutralizing antibodies of long term non
progressors inhibit HIV-1 replication through
recognition of a region whithin the first cystein
loop of CCR5
L. Lopalco, C. Barassi, S. Ghezzi, C. Pastore, G. Poli, A. Lazzarin. San Raffaele
Scientific Institute, Department of Immunology and Infectious Diseases, San
Raffaele Scientific Institute, Via Stamira DAncona 20, 20127, Milano, Italy
Background: It has been demonstrated that individuals producing anti-CCR5
HIV neutralizing antibodies are protected from HIV infection. We searched for
anti CCR5 Abs in Long Term Non Progressors (LTNP) patients, and we analyzed
CCR5 epitopes recognised by Ig from LTNP to identify the antigenic correlates of
HIV-1 neutralization. HIV neutralizing anti CCR5 antibodies may confir a relative
HIV resistance contribuing to LTNP status.
Methods: We analyzed sera from 21 LTNPs, 40 HIV+ seropositive and 45 healthy
controls (HC) searching for CCR5-specific Abs. We used abs binding on CCR5
trasfected cell line and MIP1b (natural ligand of CCR5) competition to CCR5 on
CD4+ lymphocytes. Serum Abs from LTNP with anti CCR5 Abs were affinity purified on specific CCR5 peptides, corresponding to external domains of CCR5
and tested in HIV neutralization using resting and activated PBMC as target cells.
HIV-1 primary viruses was obtained by cocultivation of PBMC from seropositive
and HC.
Results: MIP1beta binding was not modified by sera of either 40 HIV+ seropositive or 45 HC but was greatly reduced by sera of 4/21 LTNP. Binding inhibition
was due to both afinity purified CCR5 specific IgG and IgA. The CCR5 epitope
recognized by LTNP Ig was restricted to a region within the first cystein loop of
external domain of CCR5. The CCR5/first cystein loop specific Abs neutralize -R5
strains of different clades.
Conclusion: These results contribute to clarifying the phenomenon of immunological resistance to HIV and the complexity of the LTNP status. Anti CCR5 abs
may have implications for the development of both protective and therapeutic vaccines against HIV infection and disease progression.
Presenting author: Lucia Lopalco, Department of Immunology and Infectious
Diseases, San Raffaele Scientific Institute, Via Stamira D'Ancona 20, 20127, Milano, Italy, Tel.: [phone], Fax: [phone], E-mail: lopalco.lucia
@hsr.it
WePeA5777 Evaluation of oxidative stress markers and CD4,
CD38, CD95 positive T lymphocytes subsets in
HIVIAIDS patients
L. Gil del Valle1, G. Martinez 2, 1. Gonzalez 2, A. Tarinas 1, R. Molina 1,
A. Alvarez1, F Ramos 1, C. Luzardo 1, R. Tapanes 1, J. Perez1, A. Nunez3.
1I/PK, Instituto Pedro Kouri, Ciudad de La Habana, Cuba; 2I/FAL, Ciudad de La
Habana, Cuba; 3CQF, Ciudad de La Habana, Cuba
Background: Infection by human immunodeficiency virus (HIV) causes persistent chronic inflammation. Viral Tat protein plays a role in the intracellular increase
of reactive oxygen species which in turn influence the increase in the apoptosis
index, mainly the one mediated by CD95 causing a decrease of CD4 + T cell lymphocytes and more important an increase in HIV-1 replication secondary to free
radicals overproduction.

Methods: We have assessed different studies in a group of 80 HIV/AIDS patients
and 40 healthy subjects trying to obtain a global view of the redox status of these
patients. Spectrophotometric techniques were used to measure the biochemical
oxidative markers. Flow Cytometry was used to determine the CD4, CD8, CD3,
CD95, CD38 T lymphocytes subsets.
Results: An increase in free radicals productions and lipid peroxidation has been
found in these patients evaluated by hydroperoxide and malondialdehyde deter
minations (P<0.05). A depletion of antioxidant systems was detected evaluated
by total antioxidant status, superoxide dismutase, glutathione peroxidase, plasma
selenium and plasma glutathione (P<0.05). Depletions of CD4 + T cell lymphocytes counts were related with increased subpopulations of CD38/CD8 (indicators
of activation) and CD95 (indicator of apoptosis induction). The CD95 percent was
higher than CD38 (P<0.05).
Conclusions: These data indicate that oxidative stress is associated with the
progressive development of HIV by generating an environment favouring the depletion of CD4 + T lymphocytes subsets. Parameters indicating oxidative stress
could be an interesting form to screen the evolution of these patients and their
response to therapeutic regimes.
Presenting author: Lizette Gil del Valle, Instituto Pedro Kouri, Autopista Novia
del Mediodia Km 6 1/2, Marianao 13, Ciudad de La Habana, Cuba, Tel.: +53 7
2020451, Fax: [phone], E-mail: [email protected]
WePeA57781 Immunohistochemical expression of cyclin T1 in a
case of AIDS related cachessia
V. Esposito, M. Gargiulo, L. Loiacono, V. Montesarchio, R. Parrella,
V. Sangiovanni, A. Chirianni.///Div. "A.0.D. Cotugno", via S. Brigida 39, 80133
Napoli, Italy
Background: Recent identification of cdk9/cyclin T in the TAK (Tat-associated kinase) multiprotein complex, a cofactor targeted by the Human Immunodeficiency
Virus type 1 (HIV-1) protein named Tat, suggests a role for this protein in controlling transcription elongation. We characterized a polyclonal antiserum against
cyclin T1, and we investigated the pattern of expression of this protein in adult
human tissues by immunohistochemistry. Cyclin T1 was ubiquitously expressed
with different levels in various organs.
Methods: We evaluated the immunohistochemical expression of this protein in
a case of AIDS-related cachexia. Tissues from an autoptic case of AIDS-related
cachexia were formalin-fixed and paraffin-embedded. Immunohistochemistry was
carried out by streptavidin-biotin immunoperoxidase method.
Results: Cyclin T1 was widely expressed, although its distribution and/or level of
expression was different in the examined tissues. The pattern of expression found
was similar to the one already described for normal human tissues. However
we noticed that expression of cyclin T1 was very high in the widely represented
brown fat tissue. In addition the lymphoid tissues, affected by AIDS-associated
lymphadenopathy, showed high cyclin T1 expression levels in the residual elements of the germinal centers, whereas a very low immunostaining was detected
in the depleted follicles and interfollicular areas. Moreover, most of the thymic
tissue showed thymic displasia, characterized by an almost total absence of thymocytes, few if any Hassal corpuscles, and the presence of only epithelial components. In this context, cyclin T1 expression was high in the epithelial component.
Our observation that immunohistochemical expression of cyclin T1 was altered in
the AIDS-associated lymphadenopathy and in the redistributed brown fat tissue
tissue may suggest a possible involvement of this protein in the immune response
to AIDS as well as in the development of methabolic changes.
Presenting author: Vincenzo Esposito, via S. Brigida 39, 80133 Napoli, Italy,
Tel.: [phone], Fax: [phone], E-mail: esposvin @ libero.it
I WePeA57791 Suppression of CCR5- but not CXCR4-tropic HIV-1
in lymphoid tissue by human herpesvirus 6
J.C. Grivel1, Y Ito1, G. Faga2, W.S. Fitzgerald1, F Santoro2, M.S. Malnati2,
P Lusso2, L.B. Margolis'. 1National Institutes of Health, Bldg 10 room 9D49, 10
Center Drive, Bethesda, MD 20892, United States; 2DIBIT San-Raffaele, Milano,
Italy
Background: Progression to AIDS is associated with the emergence of concurrent infections that affect the course of HIV disease by mechanisms that remain
unknown. A lymphotropic agent human herpesvirus 6 (HHV-6) has been proposed as a cofactor in AIDS progression. We studied how HHV-6 affects HIV-1
infection in human lymphoid tissue ex vivo.
Methods: Human tonsillar tissue blocks cultured ex vivo without exogenous stimulation or activation were infected with either HHV-6 alone, HIV-1 alone or HHV-6
and HIV-1 in combination. We used a prototypic CXCR4-utilizing variant LAV.04,
and a prototypic CCR5-utilizing variant SF162, as well dual-tropic variants 89.6
and 89-v345SF.
Results: HHV-6 dramatically suppresses COR5-tropic and enhances CXCR4 -tropic HIV-1 replication. This was confirmed in tissue infected with a mixture of
three viruses, LAV.04, SF162 and HHV-6. HHV-6 suppresses infection of 89 -v3456SF HIV-1 that utilizes predominantly CCR5. In contrast, infection by 89.6
that preferentially uses CXCR4 was not inhibited by HHV-6 coinfection. We evaluated the production of RANTES, MIP-la and MIP-ib, in ex vivo tissues. In all the
tissues infected with HHV-6, either alone or in combination with HIV-1, we documented a dramatic increase (approximately 10-fold) in the production of RANTES.
In contrast, the levels of MIP-la and MIP-ib were variable and not significantly

augmented by HHV-6 infection compared to controls. Next, we demonstrated that
the levels of HHV-6-induced RANTES are sufficient to inhibit replication of CCR5 -tropic HIV-1 since this effect of HHV-6 could be mimicked by exogenous RANTES.
Conclusions: HHV-6 dramatically influences HIV-1 infection in human lymphoid
tissue, with a differential effect on CCR5- and CXCR4-tropic HIV-1 variants. These
data suggest that HHV-6 may be a critical factor both in containing CCR5-tropic
HIV infection and in promoting the coreceptor switch in the course of HIV disease.