Oral Presentations - Federation of Clinical Immunology Societies

S32 Abstracts
São Paulo, São Paulo, Brazil, Léia C. Rodrigues Silva, PhD
Student, Laboratory of Dermatology and
Immunodeficiencies, Medical School of the University of
São Paulo, São Paulo, Brazil, Guilherme G. Silveira,
Student, Laboratory of Dermatology and
Immunodeficiencies, Medical School of the University of
São Paulo, São Paulo, Brazil, Maury M. Tanji, Laboratory of
Dermatology and Immunodeficiencies, Medical School of
the University of São Paulo, São Paulo, Brazil, Denise
Schout, Epidemiology Service, Hospital das Clínicas,
Medical School of the University of São Paulo, São Paulo,
Brazil, Alberto J.S. Duarte, Professor, Laboratory of
Dermatology and Immunodeficiencies, Medical School of
the University of São Paulo, São Paulo, Brazil
Background: The degree Mycobacterium tuberculosis (Mtb)
immune reconstitution provided by long-term (N4 years)
successful HAART and whether a past tuberculosis (TB) history
influences this reconstitution are not known. Methods: We
compared the lymphocyte proliferative response (LPR) and IFNã
secretion to phytohemagglutinin (PHA) and Mtb antigens
(ESAT6, Ag85B and whole Mtb lysate [SMtb]) of immunereconstituted
(CD4 N500 cells/ìl) HIV+ patients with a past history of
cured TB (HIV+ CTB group) or latent infection as presumed by
positive purified protein derivative skin test (PPD+) (HIV+ PPD+
group) with HIV− controls either cured from TB (CTB group) or
PPD reactors (PPD+ group). The databank on TB incidence
among HIV+ and HIV− patients at our services during 1999–2005
was also analyzed. Results: Most HIV+ patients presented normal
PHA responses. However, Mtb immune reconstitution was
incomplete, especially to ESAT6 and Ag85B. SMtb reactivity
was fully restored in the HIV+ CTB group, while in HIV+ PPD+
patients it remained lower than in PPD+ controls. Comparison
between the two HIV groups also suggested better immune
reconstitution in HIV+ CTB patients. Databank analysis revealed
that some HIV+ patients with N360 CD4 cells/ìl still developed
TB, but not those with previous TB history. Conclusions: Mtb
immune reconstitution is incomplete in HIV+ CTB and HIV+ PPD
+ patients even after highly successful HAART. However,
reactivity to whole mycobacteria antigens is restored,
especially in HIV+ CTB patients, possibly due to survival of
higher numbers of mycobacteria-specific T cell clones throughout
immunosuppression, probably allowing sufficient protection
against new Mtb challenges.
doi:10.1016/j.clim.2007.03.266
F.53 Human CD8+ Cytotoxic T Lymphocyte Epitopes
Identified from Herpes Simplex Virus Type 1
Glycoprotein D
Aziz Alami Chentoufi, Assistant Specialist, Cellular and
Molecular Immunology Laboratory, The Eye Institute,
University of California, Irvine, Orange, CA, Xiuli Zhang,
Postdoctoral Fellow, Cellular and Molecular Immunology
Laboratory, The Eye Institute, University of California,
Irvine, Orange, CA, Kasper Lamberth, Researcher, Institute
of Medical Microbiology and Immunology (IMMI), University
of Copenhagen, 2200 Copenhagen, Denmark, Xiaoming Zhu,
Research Associate, Cellular and Molecular Immunology
Laboratory, The Eye Institute, University of California,
Irvine, Orange, CA, Gargi Dasgupta, Research Associate,
Cellular and Molecular Immunology Laboratory, The Eye
Institute, University of California, Irvine, orange, CA,
Michele Wu, Student, Cellular and Molecular Immunology
Laboratory, The Eye Institute, University of California,
Irvine, Orange, CA, Alex Nguyen, Bio-199 Student, Cellular
and Molecular Immunology Laboratory, The Eye Institute,
University of California, Irvine, Orange, CA, Ilham Bettahi,
Postdoctoral Fellow, Cellular and Molecular Immunology
Laboratory, The Eye Institute, University of California,
Irvine, Orange, CA, Søren Buus, Professor, Institute of
Medical Microbiology and Immunology (IMMI), University of
Copenhagen, 2200 Copenhagen, Denmark, Lbachir
BenMohamed, Assistant Professor, Cellular and Molecular
Immunology Laboratory, The Eye Institute, University of
California, Irvine, Orange, CA
Cytolystic T cells (CTLs) play a major role in herpes simplex
virus type 1 and type 2 (HSV-1 and HSV-2) infections and
diseases. Among some eleven HSV-1 and HSV-2 coat glycoproteins,
glycoprotein D (gD) induces immunodominant T cells and
is a leading vaccine candidate antigen. However, little is known
about human CD8+ T cell epitopes of gD. Based on predictive
computational algorithms and peptide binding affinity to HLA-
A*0201 molecules, we have identified ten regions within the
HSV-1 gD, each 9 to 10 amino acids in length, exhibiting high
affinity CD8+ Tcell epitope(s). T2 cell stabilization assay showed
peptide gD53-61, gD70-78 and gD278-286 significantly, and in
dose-dependent manner, upregulates HLA-A*0201 molecules
expression.ToobtainanobjectiveenumerationofCD8+Tcells
induced by each gD peptide epitope, we employed the HLA-
A*0201 tetramer staining procedure. A relatively high percentages
of CD8+ Tcells positive for gD-18-10, gD53-61, gD70-78 and
gD278-286/HLA-A*0201 tetramers were detected in PBMC from
HLA-A*0201 seropositive patients, either directly ex vivo or
following a single in vitro stimulation. Accordingly, strong HLA-
A*0201-restricted CD8+ CTLs, assessed by INF-γ-ELISPOT and
CD107a/b cytotoxic assays, were mapped to gD53-61, gD70-78
and gD278-286 peptides. However, only gD53-61 and gD278-286
peptides were able to generate CD8+ T cells that recognize
infected target cells. Collectively, these findings suggest that
high-affinity HLA-A*0201-binding gD53-61 and gD278-286 epitopes
are naturally processed and are recognized by HSVspecific
CD8+ CTLs in the infected human population, providing
important information for the development of subunit vaccine
strategies against herpes.
doi:10.1016/j.clim.2007.03.267
F.55 Protection Against SEB-Induced Toxic Shock by
Anti-TCR Vb8 Antibody
Manisha Singh, Postdoctoral Associate, Baylor College of
Medicine, Immunology Department, Houston, TX
Intraperitoneal injection of the bacterial superantigen,
Staphylococcus enterotoxin B (SEB) in HLA-DR3 transgenic
mice leads to toxic shock and death within 72 h. In vivo,
this is characterized by a marked expansion of splenic TCR
Vb8+ CD4 and CD8 T cells compared to PBS treated mice. It