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

XIV International AIDS Conference

Abstracts ThPeA7167-ThPeA7171 375

stimulation with mitogen PMA/Ca ionophore, whilst IFNy levels were similar in the
two groups. HIV patients also had higher numbers of cells producing IL-5 (median
100 per 200,000 cells) compared to controls (median 31 per 200,000 cells) whilst
we found no changes in numbers of IFNy producing cells between HIV patients
and controls. There was no significant difference between median levels of sCD30
and CD26 (DPPIV) in HIV patients and controls, but we found HIV patients with
elevated levels of sCD30 had reduced levels of IFNy. There was no correlation
between CD4+ T-cell count, CD8+ T-cell count, eosinophil count or viral load and
IL-5 production in HIV patients in this study.
Conclusions: We found HIV patients had increased numbers of cells producing
IL-5, whereas T1 production was similar to HIV negative controls. This study provides direct evidence for T1/T2 cytokine dysregulation in HIV patients on HAART.
Presenting author: Niamh Keane, Department of Clinical Immunology, Royal
Perth Hospital, Wellington Street, Perth WA 6000, Australia, Tel.: [phone]
2899, Fax: [phone], E-mail: [email protected]
I ThPeA71671 Increased diversity of TCRBV repertoire after 36
months of HAART
A. Giovannetti, F. Mazzetta, M. Marziali, M. Pierdominici, D. Santini Muratori,
C. Cascioli, F. Aiuti. Division of Clinical Immunology and Allergy, Univ. "La
Sapienza" of Rome, Italy, viale dell'universita 37, 00185 rome, Italy
Background: The progressive decline of CD4+ cells and the persistent antigen
stimulation induced by chronic HIV infection result in disruptions of CD4 T cell
antigen receptor variable beta chain (TCRBV) repertoire. However, the HAARTinduced changes in T-cell repertoire (TCR) diversity have not yet fully elucidated
Methods: The CD4 and CD8 TCR repertoire has been investigated by flow cytometry evaluating the expression of 24 BV gene products and by CDR-3 fragment size analysis (spectratyping). In selected patients the sequencing of the
V(D)J region was also performed.
Results: 20 HIV-1-infected patients with baseline CD4+ T cell count > 200
cells/p l and plasma viral load > 4 log10 copies/ml and naive for protease inhibitors (PI) were studied during 12 (tl 2)-36 (t36) months of HAART. A significant
increase in the percentage of CD4 and CD8 naive cells was observed during
HAART In HIV-1 infected patients the TCRBV repertoire was significantly altered
as demonstrated by numerous expansions observed in both CD4+ and CD8+
T cell subsets.The TCRBV repertoire improved during 12 months of HAART A
transient increase of Vl expansions was seen, within the CD8 subset, at t3 probably as a result of redistribution of cells from previously infammed tissues. The
diversity of the third complementarity determining region (CDR-3) was also investigated. Perturbed CDR-3 profiles were seen in CD4+ T cells of patients with
CD4 count <200 cells/pl and in CD8+ T cells from all studied patients. However,
the level of CDR-3 perturbation was only partially ameliorated by 36 months of H
AART. Preliminary data obtained by sequencing selected V(D)J regions also suggested that the diversity of TCR repertoire was only partially restored.
Conclusions: In conclusion our data indicate that HAART can restore immune
functions although some abnormalities at the level of TCR repertoire can persist
despite prolonged suppression of viral replication.
Presenting author: antonello giovannetti, viale dell'universith 37, 00185 rome,
Italy, Tel.: [phone], Fax: [phone], E-mail: antonello.giovannetti
@ uniromal.it
ThPeA7169 Interferon alpha production during primary HIV
infection correlates with impaired thymocyte
proliferation
M.L. Dion, M. Sylvestre, J.F Poulin, R. Bordi, R. Corsini, M. Lainesse,
R.P. Sekaly, R. Cheynier. Centre de Resherche du CHUM, Centre de recherche
du CHUM Hotel dieu de montreal 7014, 3840 st Urbain, H2W1 T8, montreal,
Canada
Background: The thymus is the main site where thymocytes mature into functional T cells. Thymic function has been reported to be inhibited in HIV-infected
patients. During thymopoiesis, TCR a and b gene rearrangement events give rise
to circular DNA molecules, referred to as TREC. Peripheral blood quantification
of a and b TREC reflects the level of thymic exportation. Proliferation-induced
dilution of a TREC occurs between TCR b and a rearrangement as a result
of b-selection. Thus, the a/b TREC ratio measured in periphery, evaluates prethymocytes proliferation. We therefore investigated the effect of HIV on doublenegative (DN) thymocyte proliferation in primary-infected (PI) HIV patients (<6
months post-infection). Seric IFN-a level, known to be increased during viral infection, was monitored in these patients and its effect of thymopoiesis was investigated.
Methods: PCR-based quantification of peripheral blood a and b TREC content
was performed on longitudinally-followed treated and non-treated PI HIV-infected
patients along with ELISA-based IFN-a quantification.
Results: In 6/6 early HAART-treated patients, there is a progressive decrease in
a/bTREC ratio that is reversed after a 8 to 49 weeks of treatment in 3/6 patients.

This drop of a/bTREC ratio positively correlates with IFN-a levels in all treated
patients and in 3/5 untreated patients (r* 0.96) Furthermore, a positive correlation
(r*0.38) between IFN-a and viral load was observed in 8/16 untreated and 6/7
early-treated individuals.
Conclusion: These results suggest that acute HIV infection induces IFN-a production. The anti-proliferative activity of this cytokine during early HIV infection

may impair intrathymic proliferation leading to qualitative reduction of thymic output and a possible defect in naive T cell repertoire. Early HAART treatment limits
the effect of infection on these parameters.
Presenting author: ML Dion, Centre de recherche du CHUM Hotel dieu de montreal, 7014, 3840 st Urbain, H2W1T8, montreal, Canada, Tel.: [phone]
12733, E-mail: [email protected]
ThPeA7170I Dynamics of spontaneous HIV-1-specific and
-nonspecific B-cell responses in patients receiving
antiretroviral therapy
J.M. Fondere1, V. Baillat2, J. Reynes2, J.P. Vendrell1. 'Laboratoire de Virologie,
CHU Lapeyronie, Laboratoire de Virologie, Hopital Lapeyronie, 34295
Montpellier cedex 5, France; 2Service des maladies infectieuses, Chu Gui de
Chauliac, Montpellier, France
Background: In HIV-1-infected patients receiving combined antiretroviral therapy, HIV-1 persists in lymphoid tissues in spite of sustained undetectable plasma
viremia. Since both anti-HIV-1 antibody and IgG secretion by peripheral blood
mononuclear cells (PBMC) reflect immune system activation by HIV-1 antigens,
we evaluated the impact of antiretroviral therapies on spontaneous HIV-1-specific
and -nonspecific B cell responses.
Methods: Thirty patients initiating an antiretroviral therapy were studied at baseline, 8, 16, 24, 36, and 48 weeks. Anti-HIV-1 antibody and nonspecific IgG levels
were tested by ELISA in supernatants of PBMC cultured during 7 days.
Results: An early and sustained fall in plasma viral load to below the detection limit (20 copies/ml) was observed in 17 patients, classified as sustained
responders (SR), whereas HIV-1 RNA remained detectable in the 13 others,
called incomplete responders (IR). In both groups, HIV-1-specific antibody secretion decreased significantly in parallel with plasma viral load, and polyclonal
immunoglobulin production became similar to that of PBMC controls. However,
HIV-1-specific antibody only became negative in 6 SR, who exhibited a greater
increase of CD4 T-cell counts and higher levels of the spontaneous HIV-1-specific
IgA secretion at baseline than the other SR.
Conclusions: Antiretroviral therapy induced a rapid and dramatic decrease of
spontaneous HIV-1-specific and -nonspecific B cell responses. However, our results pointed out that HIV-1-specific antibody secretion persisted in 11/17 SR patients (64%), suggesting persistent immune system activation by HIV-1 antigens
due to residual viral replication in lymphoid tissues.
Presenting author: Jean-Michel Fondere, Laboratoire de Virologie, Hopital
Lapeyronie, 34295 Montpellier cedex 5, France, Tel.: [phone], Fax: +33
46 733 8331, E-mail: [email protected]
ThPeA7171 HLA involvement in CD8+ cell noncytotoxic
suppression of HIV replication
C.E. Mackewicz, M. Ritchey, J.A. Levy. University of California, San Francisco,
University of California, San Francisco, Department of Medicine, 513 Parnassus,
HSE 1271, Box 1280, San Francisco, CA 94143-1270, United States
Background: CD8+ T cells from HIV-infected individuals can suppress HIV replication in CD4+ T cells by a noncytotoxic mechanism. Maximal suppressive activity occurs when the effector CD8+ cells and the infected CD4+ target cells are
autologous. However, complete inhibition of virus replication can be observed
at higher effector:target cell ratios when the CD8+ and CD4+ cells are HLAmismatched. The objective of this study was to directly assess the requirement
of HLA class I and class II molecules for efficient suppression of HIV by antiviral
CD8+ T cells.
Methods: Noncytotoxic CD8+ T cell antiviral activity was examined using as targets two cell line derivatives of the human B-lymphoblastoid cell line 721, one
lacking class I antigen expression (721.221 cells) and the other lacking expression of both class I and class II molecules (T2 cells).
Results: Culturing HIV-1SF33 infected 721.221 cells for as little as 48 hours with
CD8+ cells purified from nine different HLA class II-unrelated HIV-infected individuals resulted in 41-86% reduction in HIV replication. CD8+ cells from HIVuninfected individuals did not appreciably affect HIV replication. Comparable results were observed with CD8+ cells from 12 subjects when HIV-1SF33 infected
T2 cells were used as targets. Flow cytometry revealed that freshly isolated antiviral CD8+ cells did not reduce the number of 721.221 or T2 cells in respective
co-cultures.
Conclusions: The results of this study indicate that recognition of HLA class I
or class II molecules is not necessary for CD8+ cell noncytotoxic suppression
of HIV replication. The findings suggest that the mediation of this type of antiviral response does not involve classical HLA-antigen recognition at the effector
stage. We are currently examining the CD8+ cell response to 721.221 cell lines
transfected with specific HLA-A alleles to address the mechanism underlying the
enhanced antiviral activity seen in the autologous setting.
Presenting author: Carl Mackewicz, University of California, San Francisco, De
partment of Medicine, 513 Parnassus, HSE 1271, Box 1280, San Francisco, CA
94143-1270, United States, Tel.: [phone], Fax: [phone], E-mail:
[email protected]