Oral Abstract Session 01 - Global HIV Vaccine Enterprise

Topic 3: B Cell Immunology and Antibody Functions
P03.53 LB
Study on the Functional Role of Immunoglobulin E as
Surrogate Marker for HIV/AIDS Infection
B. Sonaimuthu 1 , V. Baghyanathan 1
1King Institute of Preventive Medicine & Research, Chennai,
India
Background: IgE class of antibodies has been found in mammals
and plays an important role in allergic and hypersensitivity
reactions. Certain viral infections are known to produce specific
IgE antibodies, to the extent that significant changes in the level
of total serum IgE may occur. Study attempts to associate the
Level of Ig E in HIV progression.
Methods: The study involves fifty HIV seropositive patients
attending Anti-Retroviral Therapy Centre, Department of
Sexually Transmitted Disease, Rajaji Government Hospital, and
Madurai,India subjected for the present study. The individual
involves 27 HIV/ AIDS Male patients, 23 HIV/ AIDS Female
patients. The control sample comprises 15 HIV sero negatives.
The samples were collected at the informed consent of the
patients. Serum sample were collected and IgE was quantified
using MAGIWELL IgE quantitative solid phase Enzyme- linked
Immunosorbent assay (ELISA).
Results: The study documents highest percentage of deviation
from the control observed in Male HIV seropositives (43.7%) and
age-wise influence documents highest percentage of deviation in
the age group 15- 29 years (56%).
Conclusion: Serum IgE level in the present study found to be
elevated from the normal range documents the existence of
imbalance between Th 1 and Th 2 and associated with T-cell
dysfunction and a hypergammaglobulinemia. The present results
suggest that elevation of circulating IgE levels may be due, at least
in part, to specific IgE directed to the HIV virus rather than as a
result of a nonspecific phenomenon. HIV infected adults indicate
that total IgE is also increased during the early stages of disease,
and this elevation appears to be independent of CD4 counts
and is not correlated with the levels of other immunoglobulins,
suggesting an important role for IgE as a surrogate marker of
disease progression Further research need to be exploited to
bring out the exact role of IgE in HIV pathogenesis.
P03.54 LB
AIDS Vaccine 2012
Posters
Pre-existing Humoral Immunity In Military Smallpox
Vaccinees Temporally Effects MVA-Vectored
Transgene Expression in Dendritic Cells
V. Ngauy 1 , B. Slike 2 , M. Marovich 2
1 Armed Forces Research Institute of Medical Sciences,
Bangkok, Thailand; 2 US Military HIV Research Program, MD,
USA
Background: Modified Vaccinia Ankara (MVA), a vector-based
vaccine that targets dendritic cells (DC) and induces cellmediated
immunity, is a promising HIV vaccine candidate. As
MVA vaccination strategies continue to be explored, concerns
arise regarding transferability to individuals with pre-existing
immunity to vaccina, particularly military personnel. Prior
reports suggest long-lasting vaccinia immunity after childhood
vaccination. This study, conducted in a unique cohort of adult
primary vaccinees, explores how pre-exisiting humoral immunity
to vaccinia affects entry and transgene expression of MVAvectored
vaccines in a primary human DC infection model.
Methods: Serum from military personnel vaccinated against
smallpox with either Dryvax or ACAM2000 vaccines were
obtained at 4 time points post-vaccination (n=50 per time point,
400 total). As a comparator, n=25 individuals with longitudinal
sera available at corresponding time points were studied to
compensate for inter-individual variability in response over time.
Sera were tested for inhibition of infection of DCs in vitro using
either MVA-GFP or MVA-CMDR, an HIV vaccine candidate with
env/gag/pol inserts, currently in clinical trials. Vaccinia naïve
sera served as a negative control. Vaccinia binding titers were
measured by ELISA.
Results: Vaccinia binding antibody titers waned after 5 years and
were undetectable 10 years after vaccination. Neutralizing activity,
as measured by transgene expression in DCs, confirmed this finding.
Expression and neutralization of HIV p24 (gag) expression data in
DC were equivalent to that of GFP. No differences in neutralization
activity were detected between Dryvax and ACAM2000 vaccinee
sera at corresponding time points.
Conclusion: In an adult, military, primary vaccinee population,
humoral responses to smallpox vaccination do not persist as
long as reported in the civilian population vaccinated during
childhood. This data suggests that pox-vector based vaccines
may be used in the military population, and that the age of
primary vaccination influences durability of humoral immunity.
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POSTERS