Abstracts for the 25th Annual Scientific Meeting of the International ...

Abstracts J Immunother Volume 33, Number 8, October 2010
knockdown of the genes dramatically decreased the tumorigenic
capacity, indicating that the genes could be associated with tumorinitiating
capacity of CSCs. We could induce cytotoxic T cells
(CTLs) from peripheral blood lymphocytes of cancer patients after
in vitro stimulation with SOX2-derived peptides. SP cells were
susceptible to cytotoxicity of CTLs, whereas they were resistant to
chemotherapeutic drugs. In addition, DNA vaccine encoding the
CSC gene showed higher tumor suppressive capacity in vivo in a
mouse tumor model. Our studies indicate that cancer vaccine
targeting CSCs might serve as potent immunotherapy for cancer.
Evaluation of FOXP3 Microsatellite Polymorphisms in
High-Risk Melanoma Patients Receiving Adjuvant Interferon
Ena Wang*, Helen Gogasw, Alessandro Monaco*, Lorenzo
Uccellini*, Charalampos S. Floudasw, Yanis Metaxasw, Urania
Dafniw, George Fountzilasw, Maria Spyropoulou-Vlachouw,
Francesco M. Marincola*. *Department of Transfusion Medicine,
National Institutes of Health, Bethesda, MD; w Hellenic Cooperative
Oncology Group, Athens, Greece.
Background: Attempts to identify patients who benefit from
adjuvant treatment with interferon alfa-2b (IFN) have been
disappointing. The development of autoimmunity during adjuvant
therapy with IFN cannot assist selection of patients for therapy at
baseline. The FOXP3 is located at Xp11.23 within an area of
autoimmune disease linkage and therefore is an excellent positional
candidate gene for autoimmunity at this locus. Consequently we
performed a microsatellite analysis of FOXP3 gene in the exon 0
region in high-risk melanoma patients enrolled in a study of two
regimens of high-dose IFN.
Methods: A fragment analysis was performed in the DNA of 259
stage IIb, IIc and III melanoma patients. After amplification and
electrophoresis run, data from each sample were analyzed using
Genemapper software (Applied Biosystems) which objectively calls
the fragments size.
Results: Thirteen alleles were detected (size: 284, 286, 288, 290, 292,
298, 302, 304, 306, 310, 312, 314, 316). The tabular distribution of
these alleles in melanoma patients is presented below (Table 1). At
a median follow up of 71 months (range 7.1 to 138.7 mo), 144
patients have recurred and 95 have died. There were no statistically
significant differences in the incidence of FOXP3 alleles between
melanoma patients who recurred and those with no evidence of
recurrence. RFS did not differ significantly between patients with
recurrence and those without for each of the alleles detected.
Conclusions: No allele defined by the microsatellite analysis of the
FOXP3 gene in exon 0 was correlated with improved RFS in this
high-risk group of melanoma patients.
Reshaping CD4 and CD8 Memory T Cell Proliferation by
Treating Cancer Patients with an OX40 Agonist: Immunologic
Assessment of a Phase I Clinical Trial
Magdalena Kovacsovics-Bankowski, Edwin Walker, Lana
Chisholm, Kevin Floyd, Walter Urba, Brendan Curti, Andrew
Weinberg. Robert W. Franz Cancer Research Center, Earle A.
Chiles Research Institute, Portland, OR.
OX40, a member of the TNF superfamily, is a potent costimulatory
molecule expressed upon activation at the surface of
CD4 and CD8 T cells. Its engagement improves T cell effector
function and survival. Preclinical studies have shown that OX40
agonists injected into tumor-bearing mice increase anti-tumor
immunity leading tumor-free survival in several mouse models.
These results prompted the initiation of phase I clinical trial using a
mouse anti-human OX40 agonist antibody in patients diagnosed
with a variety of solid malignancies. In this dose-escalation study,
the agonist OX40 antibody was administered on Day 1, 3 and 5 at
0.1, 0.4 and 2 mg/kg, respectively. Immune monitoring analysis,
over a 2 month period, was performed on PBL by flow cytometry
directly ex vivo, using a 10-color antibody panel detecting CD3,
CD4, CD8, CD95, CD28, CD25, CD127, CCR7, FoxP3 and
Ki-67. On Day 8-15, we have observed a 2-3-fold increase in the
proliferating CD4+ CD95+ T cells as detected by increased Ki-67
staining, mostly in the FoxP3- population with no significant
increase in CD4+ FoxP3+ T cells proliferation (Treg). The
proportion of cycling CD8+ CD95+ T cells peaked later 15-29
days after the administration of the antibody with a 2-4.5-fold
increase of cycling cells compared to a group of nine controls.
Interestingly, the middle dose (0.4 mg/kg) showed the greatest
sustained increase in proliferation for both the CD4 (non-Treg) and
CD8 memory T cell population. Administration of anti-OX40
antibody, not only triggered T cell proliferation, but also increased
the activation status of the CD8+ T cells as measured by the
co-expression of CD38 and HLA-DR on the cycling cells. Using
these two surface markers, cycling CD8+ T cells were sorted and a
gene array analysis showed increases in mRNA for CD86, CTLA-
4, and 4-1BB when compared to the non-cycling CD8+ T cells.
Flow cytometry data confirmed that Ki-67+ CD8+ T cells were
enriched for these markers. Finally, in 2 out of 3 patients, where
autologous tumor was obtained the infusion of anti-OX40
antibody appeared to increase the proportion of tumor specific T
cells. PBMC collected pre and post anti-OX40 administration were
co-cultured with melanoma cell lines. CD8 T cells, from PBMC
obtained after anti-OX40 administration showed an increase in
INF-g secretion toward autologous or HLA-matched melanoma
cell lines. These results suggest that administration of an anti-OX40
antibody in cancer patients increases tumor-specific CD4+ and
CD8+ T cells by enhancing their proliferation and the production
of type I cytokines.
TABLE 1.
Genes
No Relapse,
N = 115 (%)
Relapse,
N = 144 (%)
Allele_284 2 (1.74) 2 (1.39) 1
Allele_286 2 (1.74) 1 (0.69) 0.586
Allele_288 79 (68.70) 90 (62.50) 0.358
Allele_290 4 (3.48) 2 (1.39) 0.411
Allele_292 0 (0.00) 1 (0.69) 1
Allele_298 1 (0.87) 5 (3.47) 0.231
Allele_302 1 (0.87) 3 (2.08) 0.632
Allele_304 1 (0.87) 2 (1.39) 1
Allele_306 6 (5.22) 11 (7.64) 0.463
Allele_310 16 (13.91) 18 (12.50) 0.853
Allele_312 1 (0.87) 5 (3.47) 0.231
Allele_314 2 (1.74) 2 (1.39) 1
Allele_316 0 (0.00) 2 (1.39) 0.504
P
Characterization of Antigen Specific T Cell Activation and
Cytokine Expression Induced by Sipuleucel-T
Johnna D. Wesley, Eric Chadwick, Ling-Yu Kuan, Corazon dela
Rosa, Mark Frohlich, David Urdal, Nadeem Sheikh, Nicole M.
Provost. Dendreon, Seattle, WA.
Sipuleucel-T (PROVENGE s ) is an autologous cellular immunotherapy
designed to stimulate an immune response to prostate
cancer. PA2024 [a recombinant human antigen consisting of
prostatic acid phosphatase (PAP) and granulocyte macrophagecolony
stimulating factor (GM-CSF)] is cultured ex vivo for 2 days
with peripheral blood mononuclear cells (PBMCs) isolated from a
standard leukapheresis procedure. Sipuleucel-T obtained at Wks 0,
2, and 4, after which cells are infused back into subjects. This study
examined the T cell activation profile and cytokine production in
sipuleucel-T from men with asymptomatic or minimally symptomatic
metastatic castrate resistant prostate cancer enrolled in a Phase
3 study (D9902B, IMPACT). PBMCs from each leukapheresis
were incubated with either PA2024 or GM-CSF (sargramostim),
912 | www.immunotherapy-journal.com r 2010 Lippincott Williams & Wilkins