Split T Cell Tolerance against a Self/Tumor Antigen: Spontaneous CD4+ but Not CD8+ T Cell Responses against p53 in Cancer Patients and Healthy Donors

Analyses of NY-ESO-1-specific spontaneous immune responses in cancer patients revealed that antibody and both CD4+ and CD8+ T cell responses were induced together in cancer patients. To explore whether such integrated immune responses are also spontaneously induced for other tumor antigens, we have evaluated antibody and T cell responses against self/tumor antigen p53 in ovarian cancer patients and healthy individuals. We found that 21% (64/298) of ovarian cancer patients but no healthy donors showed specific IgG responses against wild-type p53 protein. While none of 12 patients with high titer p53 antibody showed spontaneous p53-specific CD8+ T cell responses following a single in vitro sensitization, significant p53-specific IFN-γ producing CD4+ T cells were detected in 6 patients. Surprisingly, similar levels of p53-specific CD4+ T cells but not CD8+ T cells were also detected in 5/10 seronegative cancer patients and 9/12 healthy donors. Importantly, p53-specific CD4+ T cells in healthy donors originated from a CD45RA− antigen-experienced T cell population and recognized naturally processed wild-type p53 protein. These results raise the possibility that p53-specific CD4+ T cells reflect abnormalities in p53 occurring in normal individuals and that they may play a role in processes of immunosurveillance or immunoregulation of p53-related neoplastic events

Induction of cell death in ovarian cancer cells by doxorubicin and oncolytic vaccinia virus is associated with CREB3L1 activation

We have demonstrated that oncolytic vaccinia virus synergizes with doxorubicin (DOX) in inducing immunogenic cell death in platinum-resistant ovarian cancer cells and increases survival in syngeneic and xenograft tumor models. However, the mechanisms underlying the virus- and doxorubicin-mediated cancer cell death remain unknown. In this study, we investigated the effect of the oncolytic virus and doxorubicin used alone or in combination on activation of the cytoplasmic transcription factor CREB3L1 (cyclic AMP [cAMP] response element-binding protein 3-like 1) in ovarian cancer cell lines and clinical specimens. We demonstrated that doxorubicin-mediated cell death in ovarian cancer cell lines was associated with nuclear translocation of CREB3L1 and that the effect was augmented by infection with oncolytic vaccinia virus or treatment with recombinant interferon (IFN)-β used as a viral surrogate. This combination treatment was also effective in mediating nuclear translocation of CREB3L1 in cancer cells isolated from ovarian tumor biopsies at different stages of disease progression. The measurement of CREB3L1 expression in clinical specimens of ovarian cancer revealed lack of correlation with the stage of disease progression, suggesting that understanding the mechanisms of nuclear accumulation of CREB3L1 after doxorubicin treatment alone or in combination with oncolytic virotherapy may lead to the development of more effective treatment strategies against ovarian cancer

Expression and Immune Responses to MAGE Antigens Predict Survival in Epithelial Ovarian Cancer

<div><p>The MAGE cancer-testis antigens (CTA) are attractive candidates for immunotherapy. The aim of this study was to determine the frequency of expression, humoral immunity and prognostic significance of MAGE CTA in human epithelial ovarian cancer (EOC). mRNA or protein expression frequencies were determined for MAGE-A1, -A3, -A4, -A10 and -C1 (CT7) in tissue samples obtained from 400 patients with EOC. The presence of autologous antibodies against the MAGE antigens was determined from 285 serum samples. The relationships between MAGE expression, humoral immunity to MAGE antigens, and clinico-pathologic characteristics were studied. The individual frequencies of expression were as follows: A1: 15% (42/281), A3: 36% (131/390), A4: 47% (186/399), A10: 52% (204/395), C1: 16% (42/267). Strong concordant expression was noted with MAGE-A1:–A4, MAGE-A1:–C1 and MAGE-A4:–A10 (<i>p</i><0.0005). Expression of MAGE-A1 or -A10 antigens resulted in poor progression free survival (PFS) (OR 1.44, CI 1.01–2.04, <i>p</i> = 0.044 and OR 1.3, CI 1.03–1.64, <i>p</i> = 0.03, respectively); whereas, MAGE-C1 expression was associated with improved PFS (OR 0.62, CI 0.42–0.92, <i>p</i> = 0.016). The improved PFS observed for MAGE-C1 expression, was diminished by co-expression of MAGE-A1 or -A10. Spontaneous humoral immunity to the MAGE antigens was present in 9% (27/285) of patients, and this predicted poor overall survival (log-rank test <i>p</i> = 0.0137). These findings indicate that MAGE-A1, MAGE-A4, MAGE-A3, and MAGE-A10 are priority attractive targets for polyvalent immunotherapy in ovarian cancer patients.</p></div

Patient Characteristics by MAGE Expression.

<p>PFS  =  Months Progression Free Survival. OS  =  Months Overall Survival. NA  =  upper limit not estimated.</p><p>aOther Histology includes Borderline, Carcinosarcoma, Granulosa Cell, Mixed, Sertoli Leydig, Sex Cord Stromal, Signet Ring Cell, Small Cell Type, Transitional, Anaplastic, Undifferentiated and Poorly Differentiated tumors.</p><p>Pvalues are for any difference among the columns.</p

Patient Characteristics by MAGE Serology.

<p>PFS  =  Progression Free Survival. OS  =  Overall Survival. FU  =  Follow Up.</p>a<p>Other Histology includes Borderline, Carcinosarcoma, Granulosa Cell, Mixed, Sertoli Leydig, Sex Cord Stromal, Signet Ring Cell, Small Cell Type, Transitional, Anaplastic, Undifferentiated and Poorly Differentiated tumors.</p

A–I: Immunohistochemical staining for MAGE.

<p>Specimens were stained with polyclonal antibody for MAGE-A3 (X20), clones 57b and A3 hybridoma supernatants for MAGE-A4 and MAGE-A10, respectively (x15). Specimens from the normal ovary and testis were used as negative and positive controls, respectively. A–C: Staining of the normal ovary showing no reactivity. D–F: Staining of the testis showing seminiferous tubules with strong intratubular staining, and absent non-specific reactivity. G–I: Staining of ovarian tumor demonstrating strong cytoplasmic and/or nuclear staining patterns.</p

Survival by MAGE expression.

<p>Overall survival curves for patient groups based on MAGE-A10 and –C1 expression. MAGE-C1 expression predicts an improved progression free survival and a trend towards improved overall survival. Expression of MAGE-A10 dampens survival outcomes to the degree of patients with negative MAGE expression.</p

Serum antibody and co-expression status for MAGE antigens in ovarian cancer.

<p>A total of 400 patients were studied for MAGE expression. A subset of 285 patients were studied for anti-MAGE autoantibody. The numerator represents the number of antigen positive tumors or serology. The denominator represents the total number of successful assays for each antigen. Antigen specific numbers vary due to assay viability. Percentages represent the frequency of MAGE expression or MAGE-specific antibody.</p