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

XIV International AIDS Conference

Abstracts WePeA5759-WePeA5762 17

WePeA5759 Extracellular HIV-1 Tat protein induces primary
effusion lymphoma cell (PEL) polarization and
concentrates in cell uropodes where it recruits
CD138/syndecan 1
P. Moninil, C. Chiozzini1, P. Leone', S. Baccarinil, G. Moraccil, A. Gloghini2,
A. Carbone2, B. Ensoli1. 'Laboratory of Virology, Istituto Superiore di Sanita',
Laboratory of Virology, Istituto Superiore di Sanita' Viale Regina Elena, 299,
00161 Rome, Italy; 2Centro di Riferimento Oncologico (CRO), Aviano, Italy
Background: PEL are rare lymphomas of the body cavities whose incidence is
highly increased in the setting of HIV infection. To target the body cavities, PEL
cells must migrate from distant body sites to the serous membranes. This requires the polarization of the migrating cell that is most efficiently induced by
chemokines. Since the HIV-1 Tat protein has been shown to act as a chemokine
on circulating or endothelial cells, we have studied the effects of extracellular Tat
on PEL cell polarization.
Methods: BCBL-1 cells were cultured in the presence or absence of soluble Tat
or anti-CD38 agonist antiobodies and analyzed for cell polarization, Tat binding
and heparan sulphate proteoglicans (syndecan-1) or CD38 expression or relocation by immunofluorescence assays.
Results: Upon exposure to soluble HIV-1 Tat protein BCBL-1 cells showed the appearance of prominent uropods, specialized structures that are present at the tail
edge of migrating cells. Syndecan-1, a heparan sulfate proteoglycan expressed
at high levels by PEL cells, was completely relocated in Tat-induced uropods. Internalization of soluble Tat by PEL cells was negligible and most Tat was found to
localize in the emerging uropods, likely due to direct binding to syndecan-1 heparan sulphates. However, Tat and syndecan-1 localization kinetics indicated that
Tat localizes in uropods prior to the complete relocation of syndecan-1, suggesting that cell polarization may be triggered by other Tat cell receptors. Uropods
were stabilized by Tat and lasted up to 48 hours even upon depletion of unbound
protein. Agonist anti-CD38 antibodies used as a control failed in inducing PEL
cell polarization and CD38 did not relocate in specialized cell structures upon
Tat-induced cell polarization.
Conclusions: Tat may facilitate PEL cell homing by inducing a long lasting PEL
cell polarization and by sequestering syndecan-1 that is known to inhibit cell migration in type I collagen matrix.
Presenting author: Paolo Monini, Laboratory of Virology, Istituto Superiore di
Sanita', Viale Regina Elena, 299, 00161 Rome, Italy, Tel.: [phone], Fax:
[phone], E-mail: monini @ iss.it
WePeA57601 HIV protease inhibitors block angiogenesis and
promote regression of Kaposi's sarcoma
C. Sgadari', G. Barillari2, E. Toschi', D. Carleil, C. Palladino', F Bussolino3,
P. Monini', B. Ensoli'. '1Laboratory of Virology, Istituto Superiore di Sanita',
Laboratory of Virology, Istituto Superiore di Sanita', Viale Regina Elena, 299,
00161 Rome, Italy; 2Department of Experimental Medicine, University "Tor
Vergata", Rome, Italy; 3 Institute for Cancer Research and Treatment,
Department of Oncological Sciences, University of Turin, Turin, Italy
Background: a reduced incidence or the regression of Kaposi's sarcoma (KS)
has been described in HIV-1-infected patients treated with HIV-1 protease inhibitors (PI). KS is a vascular disease particularly frequent and aggressive in
HIV-1/human herpesvirus 8 co-infected individuals. Lesion formation, in turn, is
mediated by angiogenic factors, particularly basic fibroblast growth factor (bFGF)
and vascular endothelial growth factor (VEGF). We hypothesized that the lower
incidence and regression of KS observed in treated patients was due to a direct
anti-angiogenic and/or anti-tumor effect of PI.
Methods: the effects of PI have been tested on KS-like angioproliferative lesions
induced in nude mice by inoculation of human primary KS cells or by bFGF alone
or combined with VEGF, on tumors induced by the EA-hy 926 cell line and on angiogenesis induced in the chorioallantoic membrane (CAM) assay. PI were tested
on proliferation and invasion of KS cells and primary or immortalized endotelial
cells. The gelatinolytic activity assay has been used to study the effects of PI on
matrix metalloprotease-2 (MMP-2).
Results: systemic administration of PI to nude mice blocks the development and
induces regression of angioproliferative KS-like lesions promoted by the subcutaneous inoculation of the animals with primary human KS cells, bFGF, or bFGF
and VEGF combined. Both PI also block angiogenesis induced by bFGF or VEGF
in the CAM assay with a potency similar to taxol, a drug endowed with anti-tumor
and anti-angiogenic effects. Block of angiogenesis and KS lesion formation is
mediated by the inhibition of endothelial and KS cell invasion and of MMP-2 proteolytic activation by PI, and occurs at the same concentrations present in plasma
of treated individuals.
Conclusions: these data indicate that PI are potent anti-angiogenic and antitumor molecules and that they should be exploited also in non-HIV KS, and evaluated for the therapy of other tumors in HIV-1-infected individuals.
Presenting author: Cecilia Sgadari, Laboratory of Virology, Istituto Superiore di

Sanita', Viale Regina Elena, 299, 00161 Rome, Italy, Tel.: [phone], Fax:
[phone], E-mail: sgadari @ iss.it

WePeA5761 Expression of HHV-8 latency genes modulates the
interactions between PEL cells and mesothelial
cells
P. Rimessil, M. Fabris', A. Bonaccorsi', A. Caputo', A. Gloghini2, A. Carbone2,
B. Ensoli3, P. Monini3. 1Department of Experimental and Diagnostic Medicine,
University of Ferrara, Ferrara, Italy; 2Centro di Riferimento Oncologico (CRO),
Aviano, Italy; 3Laboratory of Virology, Istituto Superiore di Sanita, Rome, Italy
Background: Primary effusion lymphoma (PEL) are rare lymphoma of the body
cavities invariably associated with infection by HHV8, which is mostly present in
PEL cells in the form of latent virus. In order to localize in the body cavities, PEL
cells must transmigrate through lymphatic or vascular endothelium. This requires
thight and irreversible cell-to-cell contact. However, as PEL cells adhere to the
serous membranes they cease any invasive behavior or disruptive growth pattern. In this study we have analyzed the role of HHV8 latent infection in the non
invasive behavior of PEL cells adherent to mesothelial cells.
Methods: Primary human mesothelial cells were isolated from pleural fluid of patients with non malignant pathologies and characterized by immunohistochemical
analysis. PEL cell lines infected by HHV8 or doubly infected by HHV8 and EBV,
and HHV8-negative non-Hodgkin lymphoma cell lines were used in adhesion assays to cultured mesothelial cells.
Results: PEL cells showed significantly reduced adhesion to mesothelial cell
monolayers as compared to HHV8 negative NHL cells, indicating that expression
of HHV8 latency genes may affect PEL cell interaction with mesothelial cells. The
HHV-8 negative Burkitt cell line BJAB, that showed strong adhesion to mesothelial
cells, was transduced with a recombinant retroviral vector expressing HHV8 latency genes, analyzed for HHV8 gene expression and tested in adhesion assays
to mesothelial cell monolayers. Adhesion of transduced BJAB cells to mesothelial
cells was greatly reduced as compared to parental cells and was comparable to
that of PEL-derived cell lines.
Conclusions: Expression of the HHV8 latency genes reduces the adhesion of
B cell lymphoma cells to mesothelial cells suggesting that latent HHV8 infection
modulates cell-to-cell contact, PEL cell transmigration and may be required to for
the non invasive behavior of PEL cells present at the body cavities.
Presenting author: Paola Rimessi, Department of Experimental and Diagnostic
Medicine, University of Ferrara, Via Borsari, 46, 44100 Ferrara, Italy, Tel.: [phone], Fax: [phone], E-mail: [email protected]
WePeA5762I Prevalence of human papillomavirus (HPV) types
in cervical samples of HIV infected Italian women
M.L. Tornesellol, I. Salatiello', M.L. Duraturo', M. Sansone2, R. Piccolo2
L. Buonaguro', FM. Buonagurol. 'Ist.Naz.Tumori, Viral Oncology
/st. Naz. Tumori "Fond Pascale", Cappella Cangiani, 1-80131 Naples, Italy;
2University of Medicine, Naples, Italy
Background: Cervical human HPV infection is more common among HIV+ than
HIV- women and is associated with higher rates of cervical squamous intraepithelial lesion (SIL). In HIV+ women a large number of HPV types are present
and little is known on the relationship between HPV types and evolution of HPVrelated lesions.
Materials: 112 HIV+ and 92 HIV- women from Southern of Italy were studied.
Cervical samples were analyzed by PCR for the presence of HPV DNA using
HPV L1 consensus primers, MYO9 and MY011, which amplify a broad spectrum
of HPV types. PCR products were subjected to direct sequence analysis followed
by homology studies in order to characterize individual HPV types. Lymphocytes
CD4 counts and plasma HIV RNA viral load were performed for each patient.
Results: HPV DNA was detected in 49 out of 112 (43.75%) HIV+ and in 10 out
of 92 (10.86%) HIV- women (RR = 4.03, 95% CI 2.2-7.5). HPV 16 was the prevalent type being found in 13.39% of the HIV+ and 5.43% of the HIV- women. The
number of specific HPV types was higher in HIV+ women [20 different HPV genotypes (6, 16,18, 31, 33, 35, 45, 52, 53, 55, 58, 61, 62, 66, 70, 72, CP8304, MM7,
MM8, LVX820)] than HIV- women [6 HPV genotypes (16, 18, 52, 61, 62, 66)] (p =
0.0032). The lymphocyte CD4 count was >500 cells/ml in 39% and <500 cells/mI
in 61% of HIV+ women; and the plasma viral load was <5.000 viral copies/ml in
55% and >5.000 copies/ml in 45% of the women.
Conclusions: Several "low-intermediate risk" HPVs, rarely found in HIV- women,
are frequently detected and considered "high-risk" HPVs in HIV+ women being
associated in this group with increased risk of cervical SIL. The prevalence of cervical HPV infection in HIV+ women is not significantly correlated nor with lower
CD4 levels neither with RNA viral load suggesting some not yet defined specific
immunodeficit and/or a direct role of HIV-1 in the activation/expression of latent
HPV infections.
Presenting author: Maria Lina Tornesello, Viral Oncology, Ist.Naz.Tumori "Fond
Pascale", Cappella Cangiani, 1-80131 Naples, Italy, Tel.: [phone], Fax:
+39-081.545.1276, E-mail: irccsvir@ unina.it