HLA-A2 Negative Patients Research Articles

The prognostic significance of HLA-A2 expression on somatic cells in patients with left-sided colon and rectal cancers

Introduction. Current knowledge about colorectal cancer (CRC) identifies tumor immunogenicity as one of the more important issues. In cancers, a prerequisite for immune system activation is the presentation of tumor associated antigen (TAA) epitopes to immunocompetent cells. HLA-A2 is one of the antigens in the context of which TAAs are present, but data on the possible impact of HLA-A2 antigen expression on the survival of patients with colorectal cancer are scarce and sometimes contradictory. The aim of this study was to analyse the relationship between HLA-A2 expression in patients with left-sided colorectal cancer in various stages of disease and their long-term survival, and to answer the question of whether a lack of HLA-A2 expression is actually a negative prognostic factor. Material and methods. A prospective analysis of 58 patients with left-sided colorectal cancer was carried out. Expression of HLA-A2 was determined by patient blood lymphocyte staining, and analysed using flow cytometry. Results. In the study group, patients with HLA-A2 expression lived statistically longer than HLA-A2 negative patients (p = 0.027). There was no significant difference in overall survival between the HLA-A2+ and HLA-A2- groups with stage II and III left-sided CRC. However, the Cox proportional hazard model showed that a lack of HLA-A2 expression was a negative prognostic factor in the group of radically operated patients without distant metastases. Conclusions. HLA-A2 status may affect the clinical course of patients with left-sided colon and rectal cancer, although left-sided tumors are less immunogenic than right-sided ones. HLA-A2-positive patients with left-sided colorectal cancer lived statistically longer than those who were HLA-A2-negative (p = 0.027). Lack of HLA-A2 expression was a negative prognostic factor in the group of radically operated patients.

Effects of HLA status and HER2 status on outcomes in breast cancer patients at risk for recurrence – Implications for vaccine trial design

Immunotherapy, using peptide-based cancer vaccines is being studied to assess its potential in breast cancer. Trials of HLA-restricted peptide vaccines have been difficult to enroll given HLA subtype restrictions. It is necessary to determine the prognostic significance of HLA-status in breast cancer if patients who are ineligible to receive a vaccine due to their HLA-status are used as controls. The impact of targeted tumor associated antigen expression, when it effects eligibility is also important. We examined control patients from two randomized phase II trials that tested HER2-peptide vaccines to determine the effect of HLA-A2 status and HER2 expression on disease-free survival. The analysis showed that HLA-A2-status does not affect disease-free survival, regardless of HER2 expression suggesting that HLA-A2 negative patients can be used as control patients. Additionally, HER2 over-expression was associated with a better disease-free survival in this population, underscoring the need for additional therapies in HER2 low-expressing breast cancer.ClinicalTrials.gov Identifier: NCT00524277

P3.02c-066 HLA-A2 Status and Immune Checkpoint Inhibitors in Advanced Non-Small Cell Lung Cancer (NSCLC) Patients: Topic: IT Biomarkers

The class I human leucocyte antigen (HLA) molecules play a critical role in tumor recognition by T cells and the loss of expression seems to be an escape mechanism of antitumoral immunity. Novel immune-targeting cancer vaccines are currently developped in HLA-A2 positive patients for modulating the T cells immune response. We hypothesized that HLA-A2 status could influence the prognosis and response to immune checkpoints (IC) inhibitors. Advanced NSCLC patients treated with nivolumab or within clinical trials (with pembrolizumab or atezolizumab) were prospectively included from November 2013 to July 2016 in our institute. HLA-A2 status was analysed by flow cytometry; PDL1 was analysed by immunohistochemistry. Clinical and biological data were collected at baseline and after cycle 1. Statistical analysis was performed with R studio. Out of 160 patients treated, HLA-A2 status was available for 65 patients. 40 patients (61.54%) were male, median age was 65 years (30-86); 55 (84.6%) were smokers and 57 (72.3%) had performance status 0-1. 42 patients (64.6%) had an adenocarcinoma, 17 (26.1%) squamous cell carcinoma and 6 (9.2%) others histologies. Molecular status was available in 55 patients: 6 (10.9%) were EGFRmut, 3 (5.4%) ALK positive, 13 (23.6%) KRASmut, 3 (5.4%) BRAFmut and 12 (21.8%) wildtype. PDL1 expression was positive in 13 patients (20%), negative in 5 (7.7%) and unknown in 47 (72.3%). The median of previous lines of treatment was 1 (1-8). HLA-A2 status was positive in 32 patients (49.23%) and negative in 33 (50.76%). HLA-A2 positivity was associated with higher number of metastases at baseline and the presence of liver metastasis (p=0.04 and p= 0.016, respectively). Other patient and tumor characteristics were well balanced between HLA-A2 + and - groups. The median progression free survival to immunotherapy (iPFS) was 4 months [0-40]. In HLA-A2 positive the median iPFS was 4 months vs 4 months in HLA-A2 negative (p=0.63). The median overall survival (OS) was 21 months [0-121]. The median OS was 18.5 months in HLA positive vs. 24 months in HLA-A2 negative patients (p=0.25). No significant difference between both HLA-A2 groups was identified. Our preliminary results suggest that HLA-A2 status has no predictive or prognostic value in NSCLC patients treated with immune checkpoint inhibitors. An updated analysis on 78 patients will be presented.

Characterization of CD8+ T-cell response in acute and resolved hepatitis A virus infection

In contrast to the infection with other hepatotropic viruses, hepatitis A virus (HAV) always causes acute self-limited hepatitis, although the role for virus-specific CD8 T cells in viral containment is unclear. Herein, we analyzed the T cell response in patients with acute hepatitis by utilizing a set of overlapping peptides and predicted HLA-A2 binders from the polyprotein. A set of 11 predicted peptides from the HAV polyprotein, identified as potential binders, were synthesized. Peripheral blood mononuclear cells (PBMCs) from patients were tested for IFNγ secretion after stimulation with these peptides and ex vivo with HLA-A2 tetramers. Phenotyping was carried out by staining with the activation marker CD38 and the memory marker CD127. Eight out of 11 predicted HLA-A2 binders showed a high binding affinity and five of them were recognized by CD8+ T cells from patients with hepatitis A. There were significant differences in the magnitude of the responses to these five peptides. One was reproducibly immunodominant and the only one detectable ex vivo by tetramer staining of CD8+ T cells. These cells have an activated phenotype (CD38hi CD127lo) during acute infection. Three additional epitopes were identified in HLA-A2 negative patients, most likely representing epitopes restricted by other HLA-class I-alleles (HLA-A11, B35, B40). Patients with acute hepatitis A have a strong multi-specific T cell response detected by ICS. With the tetramer carrying the dominant HLA-A2 epitope, HAV-specific and activated CD8+ T cells could be detected ex vivo. This first description of the HAV specific CTL-epitopes will allow future studies on strength, breadth, and kinetics of the T-cell response in hepatitis A.

Immune Responses in Patients with Metastatic Renal Cell Carcinoma Treated with Dendritic Cells Pulsed with Tumor Lysate

Patients with metastatic renal cell carcinoma (mRCC) have a limited life expectancy but still a subset of these patients develop immune and clinical responses after immunotherapy including dendritic cell (DC) vaccination. In a recently published phase I/II trials, fourteen HLA-A2 negative patients with progressive mRCC were vaccinated with autologous DC pulsed with allogeneic tumour lysate. Low-dose IL-2 administered subcutaneously was given concomitantly. In this study, we analysed lysate specific proliferation of PBMCs from these patients together with the TH1/TH2 balance of the responding T cells. Also, serum concentrations of IL-10, IL-12, IL-15, IL-17 and IL-18 from these patients and additional thirteen HLA-A2 positive mRCC patients treated with autologous DC pulsed with survivin and telomerase peptides were analysed during vaccination to identify systemic immune responses and potential response biomarkers. In HLA-A2 negative mRCC patients a spontaneous predominance of TH1 secreting tumour lysate specific T cells was observed prior to vaccination in patients attaining stable disease (SD) during treatment whereas patients with continued progressive disease (PD) had a mixed TH1/TH2 response. The TH1/TH2 balance was unchanged during vaccination also when tumour lysate specific T cell responses increased. An increase in IL-12, IL-17 and IL-18 serum concentrations was observed during vaccination but no difference between patients with SD and PD was observed. IL-10 or IL-15 was not measurable in serum.

HLA-A2 expression, stage, and survival in colorectal cancer

Most cancer vaccination trials have been performed in human leukocyte antigen (HLA)-A2 positive populations. Some studies have used HLA-A2 negative patients as control group. However, HLA-type and HLA-expression can interact with tumor biology and possibly affect prognosis. HLA-A2 negative patients might constitute an inadequate control group. Patients with colorectal cancer were serologically analyzed for HLA-A2 expression. Patients were evaluated for tumor stage, grading, tumor location. Overall survival (OAS) of HLA-A2 positive and HLA-A2 negative patients was compared. One hundred forty-four patients were evaluable (50% HLA-A2+). Median age was 62 years. UICC stage III or IV: 45.8%. Gender, location, and UICC stage were equally distributed between HLA-A2 subgroups. HLA-A2 positive patients more frequently had grade 3 histology (27.8% vs 13.9%) and chemotherapy (62.9% vs 45.6%). At a median follow-up of 75.8 months, median OAS for the entire study population was 123.3 months, 5-year OAS was 77.5%. No statistically significant difference in OAS was observed between HLA-A2 positive and negative patients (116.5 vs 157 months, 5-year-OAS 74.1+/-11.6% vs 81+/-11.6%, p=0.46). Expectedly, patients with UICC stage I and II disease lived significantly longer than patients with stage III and IV (5-year OAS 94.3% vs 53.4%; p<0.001). A significantly superior OAS was also found for women, independent of stage or HLA status. HLA-A2 positive patients exhibit poorer tumor differentiation. This might account for a non-significant difference in OAS. The use of HLA-A2 negative patients as control cohort in CRC vaccinations would rather underestimate potential treatment-related survival effects. Therefore, we suggest they constitute a valid auxiliary control group.

Lack of p21/Waf-1 expression and lymphocyte infiltration in primary ovarian cancer correlate with the somatic HLA-A2 expression

21059 Background: HLA-A2 allele is highly prevalent in Scandinavia and decreases with latitude in Europe. Similarly, ovarian cancer mortality decreases with latitude in European countries. We have previously shown that HLA-A2 is associated to a severe prognosis in serous adenocarcinoma of the ovary in stage III-IV. Others have shown that lack of p21/Waf-1 and lymphocyte infiltration in this tumour is correlated to poorer prognosis as well. Here we analyse a possible linkage between these variables. Methods: Thirty eight Swedish women with epithelial ovarian cancer were analyzed for the HLA-A genotype locus by PCR/sequence-specific oligonucleotide hybridization procedure (PCR/SSOP). Tissue slides from paraffin embedded tumour material were stained with haematoxylin and antibodies anti-p21 and -p53. Results: Twenty two patients were HLA-A2 positive. Fourteen of them (37%) lacked lymphocyte infiltration wich differed significantly from HLA-A2 negative patients (n=4, 11 %) (p=0.002). All of the HLA-A2 positive patients, with serous adenocarcinoma that showed absence of tumour lymphocyte infiltration, did not express p21/waf-1 (n=7 18 %). No cases in the HLA-A2 negative group with the same parameters were identified (p=0.009). Conclusions: These observations identify a high risk group of patients by linking together the somatic expression of HLA-A2 to the lack of lymphocyte infiltration and absence of p21/Waf-1 expression at the tumour level as prognostic negative factors. The information might have a relevant impact on the patient management.. In order to obtain a stronger power the analysis will be extended to a larger group of patients. No significant financial relationships to disclose.

Dendritic cell based vaccination in combination with IL-2 as a treatment for advanced renal cell carcinoma patients: Results from a phase I/II trial

2575 Background: Autologous dendritic cells (DC) pulsed with tumor-associated antigens as peptides or tumor lysate derived proteins can induce generation of cytotoxic T-cells in cancer patients. Survivin and telomerase are tumor-associated antigens overexpressed in renal cell carcinoma, and telomerase and survivin derived HLA-A2 binding peptides are able to induce effector T-cells cytotoxic to tumor cells. Tumor lysate can be generated from allogeneic renal carcinoma cell lines and has a natural high amount of antigens potentially enabling the induction of a polyclonal immune response against multiple targets on tumor cells. Methods: Twenty-two patients with progressive metastatic renal cell carcinoma were included and toxicity and efficacy of DC-based immunotherapy were evaluated. HLA-A2 positive patients were treated with mature autologous DCs pulsed with a broad panel of HLA binding telomerase and survivin peptides and PADRE; HLA-A2 negative patients received DCs pulsed with allogeneic tumor lysate and KLH. The vaccines were administered intradermally or intranodally weekly/biweekly ten times and repeated monthly until tumor progression. Patients received low dose IL-2 as an adjuvant. Immune response was monitored using ELISPOT assay. IL-6 and the biomarker YKL-40 were measured in serum using ELISA assay. Results: Vaccinations were well tolerated. 17/22 patients were evaluable and 10 patients had stable disease (SD) for up to 11+ months (range 2–11+ months). Interestingly, serum IL-6 increased in patients with progressive disease compared with a decrease in patients with SD. After vaccination mean values of YKL-40 were 91ng/ml in patients with SD and 208ng/ml in patients with PD. Immune monitoring is ongoing and preliminary data demonstrate that peptide specific CTLs are induced by the treatment. Conclusions: This pilot study demonstrates, that vaccination with autologous DCs pulsed with tumour antigens is safe and without severe toxicity. Disease stabilization was observed in half of the treated patients. Serum IL-6 and YKL-40 values might be useful parameters to predict clinical response during vaccination therapy. No significant financial relationships to disclose.

Human leucocyte antigen (HLA) A2 as a negative clinical prognostic factor in patients with advanced ovarian cancer

Objectives. Major histocompatibility complex antigens are mandatory for the immune response, and a genetic imbalance may be linked to tumor escape. We have previously characterized a cluster of ovarian cancer patients with high incidence of HLA-A2. To find a prognostic relevance, the presence of HLA-A2 was correlated to defined clinical parameters. Methods. A population-based set of 97 patients with confirmed epithelial ovarian cancer were recorded in a database by age, histology, stage, surgery and treatment. At the time the study was initiated, the majority of the patients were not alive and HLA-A2 expression was therefore determined by PCR/sequence-specific oligonucleotide hybridization using DNA extracted from paraffin-imbedded tissue specimens. Results. 88 patients with a median age of 65 years (36–87) could be evaluated. 44% were serous adenocarcinomas, 28% endometrioid, 6% mucinous, 13% clear cell carcinomas, 7% undifferentiated and 2% other epithelial tumors. Stages I–II comprised 33% and stages III–IV 67%. In stages III–IV and serous histology, 73% were HLA-A2 positive. Cox analysis, in this group, showed high univariate (HR7.16; CI 2.04–25.03; P = 0.002) and multivariate (HR 6.8; CI 2.10–22.4; P = 0.001) Hazard Ratios. None of the HLA-A2 positive patients survived 5 years, compared to more than 50% of the HLA-A2 negative patients. Conclusions. HLA-A2 is a negative factor for survival in women with serous adenocarcinomas of the ovary in stages III–IV. This finding has implications for clinical patient management. Association with known oncogenes needs further analysis.

Hepatitis C virus mutation affects proteasomal epitope processing

The high incidence of hepatitis C virus (HCV) persistence raises the question of how HCV interferes with host immune responses. Studying a single-source HCV outbreak, we identified an HCV mutation that impaired correct carboxyterminal cleavage of an immunodominant HLA-A2–restricted CD8 cell epitope that is frequently recognized by recovered patients. The mutation, a conservative HCV nonstructural protein 3 (NS3) tyrosine to phenylalanine substitution, was absent in 54 clones of the infectious source, but present in 15/21 (71%) HLA-A2–positive and in 11/24 (46%) HLA-A2–negative patients with chronic hepatitis C. In order to analyze whether the mutation affected the processing of the HLA-A2–restricted CD8 cell epitope, mutant and wild-type NS3 polypeptides were digested in vitro with 20S constitutive proteasomes and with immunoproteasomes. The presence of the mutation resulted in impaired carboxyterminal cleavage of the epitope. In order to analyze whether impaired epitope processing affected T cell priming in vivo, HLA-A2–transgenic mice were infected with vaccinia viruses encoding either wild-type or mutant HCV NS3. The mutant induced fewer epitope-specific, IFN-γ;–producing and fewer tetramer+ cells than the wild type. These data demonstrate how a conservative mutation in the flanking region of an HCV epitope impairs the induction of epitope-specific CD8+ T cells and reveal a mechanism that may contribute to viral sequence evolution in infected patients.

Induction of carcinoembryonic antigen (CEA)-specific cytotoxic T-lymphocyte responses in vitro using autologous dendritic cells loaded with CEA peptide or CEA RNA in patients with metastatic malignancies expressing CEA.

The application of dendritic cells (DC) to the active immunotherapy of cancer currently relies on the generation of potent DC capable of presenting tumor antigens such as carcinoembryonic antigen (CEA). It is unknown whether the T cells of patients with advanced malignancies can be reliably stimulated against tumor antigens by their autologous DC. In this study, starting with the peripheral blood mononuclear cells (PBMC) of patients with metastatic malignancies expressing CEA, autologous DCs were generated in vitro in serum-free media supplemented with GM-CSF and IL-4. The DCs from HLA A2 positive patients were loaded with the CEA peptide CAP-1 and the DCs from HLA A2 negative patients were depleted of bystander lymphocytes and loaded with mRNA encoding CEA. The DC preparations were tested to determine their phenotype and were used to stimulate autologous PBMC twice, separated by 10-14 days. The stimulated cells were then tested for their ability to lyse CEA-expressing target cells. We successfully generated an adequate number of DC for a clinical trial from all patients. The harvested DC preparations contained 49% DC and 87% DC if depleted of bystander lymphocytes. Phenotypic analysis showed the typical pattern of CD11c+ CD40+ CD86+ HLA-DR+ CD80(low) CD83(low) CD14(low). All preparations but one were able to stimulate CEA-specific cytotoxic T-lymphocyte (CTL) activity, suggesting that the majority of patients are not anergic to CEA and possess functional DC. The CTL activity was similar for the CEA peptide and CEA RNA-loaded DC.