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

372 Abstracts ThPeA7154-ThPeA7157

XIV International AIDS Conference

Abstract ThPeA7156 - Table
Total CD8 Naive Memory Memory Effector
CD8+CD27+CD45RA+ CD8+CD27+CD45RA- CD8+CD27-CD45RA- CD8+CD27-CD45RA+
% T cells 29.0 50.6 21.3* 15.6* 14.9**
% Perforin+ 26.3 12.4 19.7* 47.3 75.7
Significantly *higher, **lower, from controls [uninfected children and umbilical cord].

Presenting author: ivano mezzaroma, Viale dell'Universitb 37, 00185 Roma,
Italy, Tel.: [phone], Fax: [phone], E-mail: ivano.mezzaroma
@uniromal.it
ThPeA7154 IL-15 enhances IFN-y production by CD4 and CD8
T-cells from HIV-infected patients
G. d'Ettorre, G. Forcina, M. Carnevalini, G. Ceccarelli, N.E Di Campli,
C.M. Mastroianni, V. Vullo. La Sapienza University, Department of Infectious and
Tropical Diseases, La Sapienza University, 00161 Rome, Italy
Background: Cytokine-producing CD4 and CD8 T-cells play an important role in
the immune response. We evaluated the role of IL-15 in priming for IFN-y production by CD4 and CD8 T-cells in HIV-infected patients.
Methods: We studied: a) 6 antiretroviral-naive HIV-infected patients (mean
VL=51og; mean CD4 =73); b)6 patients with viro-immunological (CD4=817) response after HAART; c) 6 failing patients with complete viro-immunological
HAART-failure (VL=5.351og; CD4=128); d) 4 healthy donors. CD4 and CD8 Tcells were isolated by positive selection from PBMC using anti-CD4 and anti-CD8
immunomagnetic beads. Purified CD4 and CD8 T-cells were stimulated with PHA
for 3 days in medium alone or in presence of IL-15 (100 ng/ml). Cell-free supernatants were analysed for their concentrations of IFN-y by ELISA.
Results: IFN-y production (mean~SE) by CD4 and CD8 T-cells from naive
patients (86.1+5.3, 83.9~4.4, respectively) and failing patients (99.6~11.9,
92.8~19.5) was significantly lower than healthy donors (315.5~7.7, 310.5~19.6)
(p<0.005). On the other hand, increased levels of IFN-y were found in HAARTresponder patients (274.3~9.7, 270.9~14.1, for CD4 and CD8 T-cells respectively). In vitro stimulation of CD4 and CD8 T-cells with IL-15 significantly enhanced IFN-y production in naive patients (177.8~15.6, 187.7+19.7,
respectively), HAART-responder patients (339+12, 361.5~9), failing patients
(164.4~5.1, 170.2~7.3), healthy donors (387.8~2.4, 398~3.8) (p<0.001, for all
groups)
Conclusions: IL-15 enhances the in vitro priming of CD4 and CD8 T-cells for
IFN-y production in HIV-infected patients, including those receiving HAART IL-15
could play an important role in immune recovery of HIV-infected patients maintaining and/or augmenting IFN-y production.
Presenting author: Vincenzo Vullo, Department of Infectious and Tropical Diseases, La Sapienza University, 00161 Rome, Italy, Tel.: [phone], Fax:
[phone], E-mail: [email protected]
ThPeA7155 Immunological reconstitution during HAART in
HIV-1 vertically infected infants
C. Cancrini1, L. Romiti1, E. Anastasio2, A. Plebani 3, L. Cursil, P. Palma',
G. Castelli-Gattinara4, P. Rossi1. '1Tor Vergata University, Rome, Italy;
2Paediatric Clinic, Milano, Italy; 3Paediatric Clinic, Catanzaro, Italy; 4 Paediatric
Hospital "Bambino Gesb", Rome, Italy
Aim of this study was to evaluate early triple combination therapy (HAART
AZT/d4T + 3TC + NFV) effects on immune system development in HIV infected
newborns. Immunological and virological findings and CDR3 fragment lengths
analysis were performed before beginning of therapy and during follow-up in 6 infants. At the enrolment the mean age was 4.4 months (range 3-6), children were
classified as: 2 C3, 2 N1, 2 Al. Mean follow-up was 2 years (range 3-42 months).
Baseline HIV-RNA values were over 106 viral copies/mm3 in all but one children
and a marked reduction of viral load was observed, with a persistent undetectable
value (< 50 copies/ mm3) in all of them. Virological control is associated to a
marked increase or a constant high number of CD4+T cells. After a mean followup of 2 years, all the patients present normal CD4 T lymphocyte count with normal
values of CD4- CD45 RA.
CD4 TCR repertoire, performed at baseline in three patients, was normal
(Gaussian-like distribution) in child N1 and resulted highly maintained during the
therapy, while it was widely altered in child C3 and A1, but in both it was back to
normal since the sixth month of therapy. However, the CD8 TCR distribution was
deeply altered in all three children with a significant number of oligoclonal and
monoclonal patterns. During follow-up the CD8 TCRBV patterns were completely
normalized in child N1 and partially normalized in the other two.
Conclusion: Early HAART given to HIV-1 infected infants in the first 6 months of
age results in a persistent control of HIV viral load in relation with a marked immunological and clinical improvement and allows the development of a policlonal
immunological response.
Presenting author: Guido Castelli-gattinara, Ospedale Pediatrico, P.zza S.
Onofrio 4 00165, Dipartimento di Immonoinfettivologia, Italy, Tel.: [phone]
2190, Fax: [phone], E-mail: [email protected]

ThPeA7156 Impaired maturation of CD8 T lymphocytes into
effector cells in HIV infected pediatric patients
V.L. Haridas, T.W. McCloskey, R. Pahwa, S. Pahwa. North Shore-LIJ Research
Institute, Manhasset, New York, United States
Background: HIV specific effector cells and perforin expression have been described in HIV infected adults but the association between the two is not well
understood.
Methods: Perforin expression and maturation of effector CD8 T cells was examined in HIV infected pediatric patients (age 1.4 to 17.1, median 10.3yrs) on antiretroviral therapy (>3 drugs) with virus load <400-46,4901 HIV RNA copies/ml
(median 15,711). Whole blood was evaluated by flow cytometry for perforin, CD27
and CD45RA expression in CD8 T cells to examine naive, memory and effector
subpopulations (n=13) and for HIV gag and pol tetramer binding in HLA-A2+ patients (n=6).
Results: Distribution of CD8 T cell subpopulations and their perforin expression
is shown in the table above.
Perforin expression in CD8 T cells increased progressively, being lowest in naive
CD8 T cells and highest in the effector subset. HIV antigen binding cells, (gag 0.4 -2.1%, median 0.8%; pol 0.4-1.6%, median 0.9%) were predominantly CD27+ and
only a small percent expressed perforin (median 8.7% in gag+ cells and 13.1% in
pol+ cells). Perforin expression in memory phenotype (CD27+CD45RA-) of CD8
T cells correlated positively with virus load (p<0.001).
Conclusions: The correlation of perforin+ memory CD8 T cells with virus load
suggests that virus load drives their differentiation from naive to memory cells.
The predominantly memory phenotype of antigen specific cells supports the view
of a maturation arrest of HIV-specific CD8 T cells. The failure to undergo complete
differentiation into perforin enriched antiviral effector cells [CD27-CD45RA+] may
contribute to diminished cytolytic capability and ineffective cell mediated immunity
against HIV in this patient population.
Presenting author: Viraga Haridas, North Shore-LIJ Research Institute, 350
Community Drive, Pediatric Immunology, Manhasset, New York 11030, United
States, Tel.: [phone], Fax: [phone], E-mail: [email protected]
ThPeA7157 TREC+ T cell levels are inversely related to HIV
replication and are selectively and rapidly released
into circulation with antiretroviral treatment
M. Diaz-lnsual, D. Douek2, H. Valdez1, B. Hill2, D. Peterson3, I. Sanne4,
P. Piliero5, R. Koup2, S. Green', S. Schnittman6, M. Lederman'. 'CWRU,
Cleveland OH, United States; 2NIAID, Bethesda MD, United States; 3 UT
Southwestern, Dallas TX, United States; 4U Wittwatersrand, Johannesberg,
South Africa; 5Albany Medical College, Albany NY, United States; 6Bristol Myers,
Wallignford CT United States
Background: T cell receptor rearrangement excision circles (TRECs) can be
used to estimate the proportion of recent thymic emigrants in peripheral blood.
Methods: We examined clinical and laboratory correlates of baseline and ontreatment TREC levels among 44 treatment-naive patients who started therapy
with atazanavir or nelfinavir and at week 2 added didanosine and stavudine.
Results: At baseline, both age and HIV RNA negatively correlate with CD4+
TREC proportions (r=-0.34, p=0.022, and r=-0.41, p=0.006). Baseline HIV RNA
levels also were negatively correlated with CD8+ TREC proportions (r=-0.42,
p=0.005). TREC proportions correlated with the numbers of naive phenotype
CD4 cells (r=0.43, p=0.004) but not CD8 cells (r=-0.01, p=0.944). This was likely
a consequence of sustained CD8 cell expansion in HIV disease as absolute CD8
TREC numbers did not correlate with absolute CD8 cell numbers. The proportions
of CD4+ and CD8+ cells expressing CD38+ correlated negatively with the proportions of TREC containing CD4+ (r=-0.39, p=0.01) and CD8+ (r=-0.50, p<0.001)
cells respectively. When adjusted for their relationships with CD38 expression,
the correlation between HIV RNA levels and TREC decreased (r=0.40 to 0.29
for CD4 cells, and r=0.42 to 0.31 for CD8 cells). This is consistent with a model
wherein the effects of HIV replication on TREC levels are at least in part mediated through immune activation. After 2 weeks of antiretroviral therapy, significant
increases in the proportions of TREC+ CD4 cells (from 0.020 to 0.037, p=0.012)
and CD8 cells (from 0.009 to 0.017, p<0.001), and absolute TRECs (p=0.005)
were seen. Thereafter, both proportions and absolute numbers of TREC+ cells
experienced non-significant decreases.
Conclusions: These findings suggest that HIV replication decreases TREC levels in blood in part through selective sequestration that may be mediated through
immune activation. Most TREC increases are seen within the first two weeks of
therapy.
Presenting author: mireya diaz-insua, dept. of epidemiology and biostatistics,
wg-57 school of medicine, case western reserve university, cleveland, oh 44106,
United States, Tel.: [phone], Fax: [phone], E-mail: mcd8@po.
cwru.edu