Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 21211-21216 281

I 111 Three types of env and gag-containing plasmids for DNA
immunization against HIV-1
Jun Fukushima, K.H. Hamajima, T.Y. Yokohama, S.K. Kawamoto, K.N. Nishioka,
K.O. Okuda. Dept. Bacteriology Yokohama City Univ., Yokohama, Japan
Objectives: To determine the most effective antigen genes of HIV-1 in DNA
immunization for getting cross-reactive immunity.
Methods: The expression plasmids of three types of env from HIV-1 IIIB
(Subtype B, T-cell tropic); pCMV160IIIB, BAL (Subtype B, Macrophage tropic);
pCMV160BAL, and Thai E (Subtype E, tropism unknown); pCA160E were constructed. The gag-based expression plasmids, pCMVGAG, pCMVGAG-POL, and
pCMVGAG-POL-ENV (BAL) were also constructed. These expression plasmids
were injected into mice muscle and then humoral and cell-mediated immunological
responses were monitored by enzyme-linked immunosorbent assay, delayed-type
hypersensitivity, and cytotoxic T lymphocyte assays using deferent antigens.
Results: Among these three envs, BAL DNA immunization is the most effective for getting cross-reactivity in the cell-mediated immunities (CMI) against
envelope. We also evaluated the immunological responses using gag-based
expression plasmids immunization. CTL responses against Gag protein were
obtained by these gag-immunized mice. The envelope-specific CTL was also detected by the immunization of gag-pol-env expression plasmid. The comparison
of CTL activities from the mice injected with pCMVGAG-POL-ENV and pCMVGAG-POL + pCMV160BAL in deferent muscles showed that higher CTL activities
are obtained from the mice injected with two independent plasmids into deferent
muscles.
Conclusions: The injection of gag-pol and env expression plasmids independently into different muscles are seemed to be effective method for getting
CMI against Gag and envelope protein, and BAL envelope gene injection is a
candidate for getting cross-reactive CMI.

121212

Effect of a gpl20-depleted inactivated HIV-1 immunogen
(Remune ) on the control of nuclear factor kappa-B
activation and cytokine production in primary human
T cells

Eduardo Fernandez-Cruz, M.A. Munoz Fernandez, J. Navarro Caspistegui,
J.L. Jimenez Fuentes, M.L. Abad Alastruey. Hospital Gregorio Marahon.
Servicio Inmunologia, Madrid. 28007, Spain
Background: The transcriptional factor, NF-kB, plays an important role in HIV-1
LTR driven transcription in primary T cells. TNF-y induces HIV-1 replication
through activation of NF-kB. Thl and Th2-type cytokines are involved in the
mechanisms of the immune dysregulation associated with disease progression.
REMUNE has shown several immunomodulatory and antiviral properties which
could be of benefit against HIV-1 disease at various levels. In order to determine
how REMUNE affects the immune system we have investigated its effect on the
induction of NF-kB and production of cytokines in purified activated T cells.
Methods: T cells obtained from PBMC from healthy HIV-1 seronegative donors
were purified by passing the nonadherent population through a nylon fiber wool
column. Different concentrations of REMUNE were added to purified T cells
activated with an immobilized anti-CD3 antibody. NF-kB activation and cytokine
production were evaluated by electrophoretic mobility shift assay (EMSA) and
specific ELISA, respectively.
Results: The presence of REMUNE" (10 pg/ml) in the culture inhibited the
appearance of NF-kB binding activity in the nucleus of T cells 4 hrs after activation (1673 A.U. as compared to control 3586 A.U.). HIV-1 Immunogen inhibited
significantly the production of TNF-u in a dose response manner (54.5 ~ 22%);
increased significantly in a dose response manner the production of Interferon-g
(345 1 231%); and inhibited significantly the production of IL-5 (32.2 ~ 17%)
(the results show the effect of the optimal dose of 10/gg/ml REMUNE" and are
the mean I s.e. from 3 experiments with different donors, each one carried out
in triplicate, standarized as % control). HIV-1 immunogen had no effect in T cell
proliferation and on IL-2 and IL-4 production by stimulated purified T cells. The
effect of the HIV-1 Immunogen (up to 25 /g) was not due to a toxic effect, since
no decrease in viable cell number, tested by trypan blue exclusion, was observed.
Conclusion: The immunomodulatory and antiviral properties of REMUNE'"
could be explained by the inhibition of NF-KB and TNF-a and the induction of Th1
-type responses. A clinical trial is ongoing in Spain to confirm the clinical utility of
REMUNE ' in combination with antiviral drugs.
1213 Intranasal administration may be one of ideal immunizing
route for HIV-1 DNA vaccine
Kenji Hamajima1, J.-F. Fukushima1, S.-S. Sasaki1, K.-X. Xin2, T.-K. Kaneko1,
S.-K. Kawamoto1, K.-O. Okuda. ' Yokohama City University, 3-9 Fukuura
Kanazawa -Yokohama 236; 2Jichi Medical School, Japan
Objectives: To examine whether intranasal (i.n) administration of HIV-1 DNA
vaccine is capable of inducing high level of HIV-specific immunities as well as
intramusclar (i.m) immunization.
Design: Experiment on animals. Evaluating adjuvant effect of IL-12 expression
plasmid on the HIV-1 DNA vaccine via i.n. administration.
Methods: The HIV-1 DNA vaccine containing HIV-1 IIIB env and rev plasmid
was administrated with IL-12 expression plasmid to BALB/c mice by i.n. and i.m.
routes. Ig isotype of fecal extract and vaginal fluid samples from the mice was
measured by ELISA using IIIB en v synthetic peptide as antigen and cytokine
(IL-4 and IFN)/) induced in culture fluids by commercial kit. Footpad swelling

responses directed to HIV-1 peptide and CTL activities of restimulated spleen
cells were also measured in vitro.
Result: Similar levels of humoral and cell-mediated immunities (CMI) were
induced in the mice i.n. and i.m. administered HIV-1 DNA vaccine alone, and
i.n. administration of HIV-1 DNA vaccine induced Th2-type dominant immune
response compared to i.m. administration. However administration of HIV-1 DNA
vaccine with IL-12 expression plasmid indcced higher levels of both humoral and
CMI responses.
Conclusion: Intranasal immunization of HIV-1 DNA vaccine with IL-12 expression plasmid induces strong both mucosal and CMI immune responses against
HIV-1 antigen
121214 Neutralizaion of macrophage and T cell line tropic viruses
by a bivalenet subtype B/E vaccine designed for Asia
Phillip Berman1, W. Huang2, L. Riddle3, T. Wrinn2, D. Francis1, M. Clasen3,
T.J. Gregory3. 1 Vaxgen, Inc. So. San Francisco, 501 Forbes Blvd South San
Francisco, CA 94080; 2Cell Culture R&D-Genetech, Inc. So. San Francisco, CA,
3Process Sciences-Genetech, Inc. So. San Francisco, CA, USA
Background: Genetic analysis has shown that the majority of HIV-1 infections
in the USA and Western Europe are due to subtype B viruses, whereas in parts
of Asia (e.g. Thailand) both subtype B and subtype E viruses are in circulation.
In this report, a bivalent subunit vaccine designed to provide protective immunity
against infection by subtype B and subtype E strains of HIV-1 was evaluated in
preclinical immunogenicity studies.
Methods: Recombinant gp120 was prepared from a prototypic subtype B virus
(HIV-1 MN), representative of viruses circulating in the USA and Western Europe,
and a prototypic subtype E virus (HIV-1CM244), representative of viruses circulating in Thailand. Rabbits were immunized with these antigens alone and in
combination. The resulting antisera were evaluated for gp120 binding, reactivity
to V3 domain peptides, and for neutralization of CXCR4 and CXCR5 dependent
virus isolates from the United States and Thailand.
Results: Studies with monovalent formulations showed that the immune responses to both antigens were highly cross-reactive and sometimes elicited
antibodies capable of inter-subtype virus neutralization. Antibodies to the bivalent formulation neutralized viruses possessing a variety of diverse phenotypes,
including syncytia inducing (SI) and non-syncytia inducing (NSI) primary isolates,
viruses using either the CCKR5 or CXCR4 chemokine receptors, and viruses
differing in their sensitivity to soluble CD4.
Conclusion: Recombinant gpl20s prepared from subtype B and subtype E
viruses elicit antibodies able to neutralize both macrophage tropic and T cell line
tropic viruses. Combining antigens representing two distinct genetic subtypes
increased the potency and reproducibility of the intersubtype virus neutralizing
antibody response.
121215 Lymphocyte proliferative response following
immunization with a novel HIV-1 V3 recombinant
multi-epitope polypeptide: TAB 9
Beatriz C. Sierra1, S. Resik2, A.B. Perez3, V. Kouri4, C. Duarte5. Institute "Pedro
Kouri", Autopista Del Mediodia KM6, PO. Box 601 Mariano 13 Ciudad, Habana,
Cuba
Issue: As the HIV epeidemic continues to spread world wide, the need for an effective vaccine remains urgent. Because T cell responses are critical for defense
against viral infection, an ideal vaccine should stimulate these cells.
Project: The V3 region of gp120 is considerate to play a key role in viral
infectivity and contains the principal neutralizing domain of the virus. TAB9 is a
Multi-Epitope Polypeptide (MEP) including the V3 regions from six HIV isolates
(LR50, JY1, RF, MN, BRVA and IIIB). In this work we have attempted to study the
cellular immune response to TAB9 following immunization of healthy adult male
volunteers. As a model system, we have measured lymphocyte proliferation to
TAB9, control
Method: Antigens and phytohaemaglutinin in two groups of volunteers immunized with two different dose and in a control group.
Results: Both groups immunized with TAB exhibited lymphoproliferative response to TAB9 after the third vaccine dose except one volunteer of the lower
dose group. The response was dependent on the dose. Of the control group (only
adjuvant) none except one showed proliferative response to TAB9.
Lessons Learned: This study demonstrated the ability of the HIV-1 MEP vaccine to induce helper lymphocyte memory as measured by in vitro lymphocyte
proliferation. Recognition of this MEP by HIV infected humans and by citolytic T
cells remains to be examined.
|21216 Multi-epitope polypeptide TAB9 adjuvated with
montanide ISA720 is highly immunogenic and induces
neutralizing antibodies in macaques

Carlos A. Duarte1, C.E. G6mez1, L. Navea2, L. Lobaina2. Centro de Ingenieria
Genetica y Biotechnologia Apd 06162, Playa, La Habana; 2Laboratorio de
Investigaciones de Sida, La Habana, Cuba
Objectives: To evaluate the safety and immunogenicity of the Multi-Epitope
Polypeptide TAB9 in M-ISA720 in macaques
Methods: Macaques (Macaca fascicularis) were immunized with TAB9 in
M-ISA720 on months 0, 1, 6 and 12. Four animals received 200 /g of TAB9,