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

Track A: Basic Science

Tu.A.2012 -Tu.A.2017

Tu.A.2012
HIV-MEDIATED BLOCKADE OF THE INTEGRIN-TRIGGERED CELL SURVIVAL
SIGNAL WHICH RESCUES T LYMPHOCYTE APOPTOSIS
NiTonylCI, Kanner S2, Humphries M3, Nye KI, Anderson J1,4, Khoo S5, Morrow WJW1I,
ImmunologyI, Genitourinary Medicine4. Depts., St. Bartholomew's Hospital, UK; 2BristolMyers Squibb Pharmaceutical Research Institute, Seattle, USA; 3School of Biological
Sciences, University of Manchester, UK; 5Department of Infectious Diseases, North
Manchester General Hospital, UK.
Background/Rationale: 01-integrin engagement has been shown to rescue various cell types
from undergoing apoptosis. Activation induced T cell apoptosis constitutes an important
pathogenetic mechanism in HIV infection.We compared the integrin-triggered "cell survival
signal" and associated pathways in healthy donorT lymphocytes with that observed for HIVinfected individuals.
Methods: Following stimulation with a novel anti-I-integrin activating antibody, changes in
the expression of focal adhesion kinase (ppI25FAK) (a key signaling protein within the integrin signaling cascades) and extracellular signal- regulated kinases (ERKI and ERK2) in
peripheral blood Tcells were assessed by immunoblotting and/or semiquantitative PCR
assays.The ability of the integrin-induced survival signal to reverse HIV-related, antiTcR/CD3-induced apoptosis in patient lymphocytes was examined by cell cycle analysis
using propidium iodide in conjunction with the TUNEL assay and 3Hthymidine uptake studies.1-cell secretion of interferon (IFN)-y (previously shown to suppress anti-TcR/CD3 -induced apoptosis) in response to TcR/integrin costimulation was measured by ELISA.
Results: TcR/integrin-costimulated proliferative responses and integrin-mediated protection
from TcR/CD3 induced apoptosis were absent in the majority of patients with AIDS, but
intact in asymptomatic individuals (pc0.05). Integrin induced augmentation of antiT cR/CD3 stimulated IFN-ysecretion by healthy donor I-cells was absent among HIV-infect
ed individuals (p=0.003).The mechanism of integrin hyporesponsiveness appeared to corre
late with a liack of or reduction in the expression of pp125FAK and downstream effector
molecules ERK +2.The suppressed pp125FAK expression may be partly explained by a
combination of transcriptional arrest and mRNA destabilisation.
TIC. Ng, Dept. Immunol., 38 Little Britain, London EC IA 7BE, UKTel:(44)171-60 1 -8104
FAX:[phone] e mail:t.ng(amds.qmw.ac.uk
Tu.A.2013
Shapshak Paul*, Bradley W*, McCoy C*, Goodkin K*,Yoshioka M**, Nagano I*", Crandall
K***, Xin KQ***, Fujimura R*, Delgado S', Stewart R*, Matthews A*, Zhang B*,Yang J*.
*U. of Miami, Miami, FL; **Tohoku Brain Inst, Sendai, Japan ***U. of Texas,Austin.TX;
** Yokohama City Med. Schl,Yokohama, Japan
Objectives. To determine if: HIVI infection and host toxic factors are associated with central nervous system (CNS) and peripheral nervous system (PNS) disease; the macrophage
is central to neuropathology as the site of preponderant virus load and as the source of
toxic factors; drug abuse increases risk for neurological dysfunction.
Methods. These studies are dependent on post-mortem tissue donation which we receive
from the Medical Examiner's office. During the last several years we have accumulated 205
cases (1 08 HIV + and 97 HIV).We use in situ hybridization (ISH), immunohistochemistry
(IHC), and polymerase chain reaction (PCR) to detect HIV I and cytokines and to identify
the cells involved, and DNA sequencing to characterize strains of HIV I.
Results. In vitro: cocaine and cocaethylene perturb (inhibit) surface marker (CD I I, CD 14,
CD68, and HLADR) expression of macrophages purified from brain using immunomagnetic
bead procedure. Ex vivo: activated macrophages including multinucleate giant cells are the
major reservoir of HIV I infection in the CNS but are rare in the PNS. In both CNS
(dementia) and PNS (neuropathy), cytokines are involved in neuropathogenesis. In the PNS,
cytokines may be related to apoptosis, levels of nitric oxide synthase, calbindin, parvalbumin,
and nodules of Nageotte.There is segmental demyelination in HIV + sciatic and sural
nerves but not in tibial nerves. In both CNS and PNS, these events may result in the subsequent demise of the nervous system.Virus load and/or virus strains may be more related to
CNS than PNS dysfunction and Neuropathology
Conclusions. The use of IHC, ISH, PCR, DNA sequencing, and culture techniques provide
insight into processes that may be involved in the pathogenesis of AIDS neurological dysfunction. Drugs may be associated with additional neuropsychiatric disease. A general model
of HIV neuropathogenesis is: HIV infection->strain divergence>macrophage/monocyte/inflammation->toxic molecules->?->apoptosis ->->disease.
Dr P Shapshak, Psychiatry Elliot Bldg 2026, U of Miami Med School I 800 NW 10th Ave,
Miami, FL 33136 tel. [phone] fax [phone] email
pshapsha2amednet.med.miami.edu
Tu.A.2014
HIV-I ENVELOPE AS A CORRELATE OF DELAYED PROGRESSION TO AIDS
*Grovit FerbasKaothie, *Ferbas J. **Parekh A. **Sadeghi S, ",Kaplan A, *Giorgi J, ",*O'Brien
WA. *University of California at Los Angeles, Los Angeles CA; "W Los Angeles VAMC,
Los Angeles CA
Objectives: tV-I phenotypes associated with enhanced replication have been linked with
rir cal progress or, and these phenotypes have largely mapped to the HIV I envelope
(irw).To determine whether /ong term survival of HIV-I infection can be attributed to
in/ection with a relatively avirulent strain, we have exarined genetic and phenotypic determinants of the HIV I envelope protein of the infecting virus.
Methods: RNA was purified from the blood of 6 individuals infected for > 10 years who
have not progressed to AIDS, and fromi 2 rapid progressors. AlI donors were selected fromr
the Multicenter AIDS Cohort Study (MACS). RNA was diluted to the limit of detection for
ri speci c Reverse Transcriptase Polymerase Chain Reaction (RT-PCR).Twelve independent clones/sarple were constructed ol/owing 24 individual RPCRs. Gel purifed PCR
products were ligated into the vector pCR II, and used for env sequence analysis. FulH/ength
chimeras were conslructed in a pNllI3 backbone, and virus stocks were generated follow
n electroporation of prima ryT cells.
Results: We have characterized env fom I of 6 delayed progressors. It was previously
demonstrated that the virus from this individual grew slowly in culture with purifed CD4+
T cells.Twelve env specific clones were constructed from each of the following three
sources: I) the celoular mRNA betore, and 2) three weeks after in vitro co culture, and 3)

the rlasma HIV-specific RNA.TheV3 sequences of these clones derived >10 years after
sereconversion were heterogeneous. Nonetheless, the majority of clones were consistent
with macrophage-tropic and non syncytium-inducing (NSI) isolates. An N linked glycosylation site was absent in the clones derived from plasma and cellular mRNA prior to culture,
but was present after culture. Recombinant viruses derived from mrRNA isolated before co
culture were macrophage- tropic, and NSI in primary cells.
Conclusions: The absence of a well conserved N linked glycosylation site, the observance
of macrophage tropism, and the lack of cytopathicity in these viruses may in part, confer the
viro ogic properties that lead to viral attenuation, and the lack of CD4 lymphocyte destruc
tion,

K Grovit -Ferbas, UCLAVAMC WVLA Bldg 14, Rm 320, Los Angeles, CA L
(310) 478-371 I ext 43336 Fax: [phone] email: kferbas(aucla.edu

)73 Telephone:

Tu.A.2015
THE TCR-AUTOIMMUNITY MODEL OF AIDS PATHOGENESIS
Hoffmann Geoffrey W. Imrnune Network Research Ltd. and University of British Columbia,
Vancouver; BC, Canada
An idiotypic network model of AIDS pathogenesis has been formulated in which the T cell
receptor plays a role both in nfection and as a target of autoimmunity (Scanrd rJ. Irn o,
41, 331-337, 1995). In the model HI-V specific T cells are preferentially infected, and HfIV act
ing as an antigen, both stimulates and infects these cells.The IlV variants that rc most
strongly selected are those that are recognized by the most helperT cells. HIV and suppres
sor T cells are subject to the same selective environment, namely that provided by the
helperT cell diotypes, and consequently undergo a process of convergent selection to
resemble each other more and more with time. Eventually immunity ager nst IIVc re
reacts wth suppressor 1cel idiotypes, disrupting the nor rial regulation of hel per cells,
and autoimmunity ensues.This model accounts for a wide range of expcirentally
observed phenomena and leads to novel vaccine rd ter io py approaches involving the tar
geting and elimination of HIV specfico cells.Recent pro gss towards understanding AIDS
pathogenesis in the context of this model will be reviewed.
Geoffrey W HffHfmann, Irmmune Network Research Ltd. 3650 Wesbrook MallVancouver,
BC, Canada,V6S 2L2.Tel: [phone] Fax: [phone]
Tu.A.2016
ANALYSIS OF A LYMPH NODE DURING HIV-I SEROCONVERSION
Martin DJ*, Morris L*, Gray CM*, Lyons, SF*, Murray J., 0Sonnenberg, P***. *MRC AIDS
Unit, National Institute for Viroloy Johannesburg "National Centre for Occupational
Health, Johannesburg, South Africa **Epidernmiology Research Unit, Medical Bureau tfor
Occupational Diseases, Gold Fields West Hospital, South Africa
Objectives: To describe structural and functional changes in a lymph node during acute prmary HIV-I infection.
Methods: A patient presented with an acute illness associated with significant diffuse gener
alised lymphadenopathy Diagnostic work up was negative for an aetiological diagnosis. A
biopsy of a chest wall lymph node was performed to exclude a lymphoma. Repeated testing for HIV infection had been negative in the past during visits to a STD clinic, the most
recent negative result being obtained II days prior to the biopsy. Blood samples were test
ed again at the time of the biopsy because acate primary HIV infection was included in the
differential diagnosis.
Results:The blood specimen collected at the time of the biopsy gave indeterminate results
for HIV antibodies on both ELISA and western blot tests. Subsequent testing confirmed HIV
infection. A p24 antigen test was slightly eleva:ed suggestive of recent viraemia.
Histological sections of the lymph node revealed hyperplasia in the germinal centres which
coalesced to form large confluent geographic zones with a prominence of plasma cells in
the cortical zones. Staining with CD2 1 revealed a striking and extensive reticulum network
of FDC within the germinal centres. B cells were abundant in the mantle zone and T cells
and IDC were abundant in the paracortex.
Functional studies of this lymph node using a combination of flow cytometry and RTPCR
showed an increased percentage of CD19 B cells and CD4 - T cells compared to concomitant measures in the peripheral blood. There was also an absence of NK cells in the
lymph node compared to the peripheral blood. Intracytoplasmic staining of ceas for
cytokines and RT-PCR for cytokine mRNAs detectled I L-, IL-2,I 6, IL- 10,TNF and IFN-y
indicating a high level of cytokine gene expression.
Desmond J Martin, National nstitute for Virology, Private Bag X4, Sandringham 2131, South
Africa.Telephone: +27 I 882 9910, Fax: +27 I 882 0596, e -mail: desm(@niv.ac.za
Tu.A.2017
APOPTOTIC DEATH OF PERIPHERAL BLOOD T LYMPHOCYTES SHOWN
DIRECTLY EX-VIVO IN HIV-INFECTED PATIENTS
Te Velde LF, Batenburg EM. Haanen CVermes I, Ten Napel CHH. Medisch Spectrum
Hospital, Enschede, Netherlands.
Objective: To determine apoptotic cell death in circulating lymphocytes of HIV infected
patients in comparance with levels in healthy controls.
Methods: Apoptosis of lymphocytes was measured ex vivo with a lowcytometric assy
probing for expression of phosphatidylserine (PDS) with Arnnexin-VThe exposure of phosphatidyl serine is seen in the early phase of apoptotic cell death. Cell membrane integrety
was controlled by Propidiurm Iodide (PI) exclusion. Manonuclear cells from peripheral blood
drawn frnom 15 fHIV infected patients and 15 healthy controls, were isolated by Ficoll and
subsequently incubated with FITC- labeled Annexin- V and PI respectively Lymrphocytes were
selected by a combination of low angle forward scatter and right angle scatter properties.
Result: The percentage of necrotic cells (PI+, was lesser than.5% in both groups and in
healthy controls the percentage of apoptotic cells was ess than 3%. In HIV-infected persons
of all clinical stages of infectio, a vst incrse of 1poptotilymphocytes was seen ranging
from 5.5 34.5 (median I5.9).There was a trend towards assocition of higher percentages of apoptosis with ad nced clinical disose staige. Apoptosis was seen in further experi
ments us ng double immunofluorescent labeling to exist in CD4+ve as well,s CD8+velymphocytes.
Conclusion: Our results show an increase of the early sta4e of apoptotic cell death in T
lymphocytes derived from HIV infected persons of all clinical taes. Either th

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