Does HLA type predispose some individuals to cancer?

Germline homozygosity and allelic imbalance of HLA-I are common in esophagogastric adenocarcinoma and impair the repertoire of immunogenic peptides

BACKGROUND

The individual HLA-I genotype is associated with cancer, autoimmune diseases and infections. This study elucidates the role of germline homozygosity or allelic imbalance of HLA-I loci in esophago-gastric adenocarcinoma (EGA) and determines the resulting repertoires of potentially immunogenic peptides.

METHODS

HLA genotypes and sequences of either (1) 10 relevant tumor-associated antigens (TAAs) or (2) patient-specific mutation-associated neoantigens (MANAs) were used to predict good-affinity binders using an in silico approach for MHC-binding (www.iedb.org). Imbalanced or lost expression of HLA-I-A/B/C alleles was analyzed by transcriptome sequencing. FluoroSpot assays and TCR sequencing were used to determine peptide-specific T-cell responses.

RESULTS

We show that germline homozygosity of HLA-I genes is significantly enriched in EGA patients (n=80) compared with an HLA-matched reference cohort (n=7605). Whereas the overall mutational burden is similar, the repertoire of potentially immunogenic peptides derived from TAAs and MANAs was lower in homozygous patients. Promiscuity of peptides binding to different HLA-I molecules was low for most TAAs and MANAs and in silico modeling of the homozygous to a heterozygous HLA genotype revealed normalized peptide repertoires. Transcriptome sequencing showed imbalanced expression of HLA-I alleles in 75% of heterozygous patients. Out of these, 33% showed complete loss of heterozygosity, whereas 66% had altered expression of only one or two HLA-I molecules. In a FluoroSpot assay, we determined that peptide-specific T-cell responses against NY-ESO-1 are derived from multiple peptides, which often exclusively bind only one HLA-I allele.

CONCLUSION

The high frequency of germline homozygosity in EGA patients suggests reduced cancer immunosurveillance leading to an increased cancer risk. Therapeutic targeting of allelic imbalance of HLA-I molecules should be considered in EGA.

Human leukocyte antigen HLADRB1 determinants susceptibility to gastroesophageal reflux disease

BACKGROUND

- Gastroesophageal reflux disease (GERD) is characterized by diverse symptoms. There is an evidence for a genetic component to GERD as supported by familial aggregation of this disease.

OBJECTIVE

- To investigate whether certain human leucocyte antigen genes HLA-DRB1 are associated with GERD.

METHODS

- Patients and controls were prospectively recruited from GIT center at Al-Kindy Teaching Hospital (Baghdad-Iraq) between January 2014 and July 2016. Sixty Iraqi Arab Muslims patients with a history of heartburn and dyspepsia compared with 100 Iraqi Arab Muslims controls. All study patients and control groups underwent upper gastrointestinal endoscopic examinations and their serums were analyzed for CagA antibodies Immunoglobulin G (IgG) for H. pylori. HLA-DRB1 genotyping were done to both groups.

RESULTS

- A total of 60 patients with erosive gastritis; GERD (Grade II and III) were evaluated, together with 100 controls. There is a significant increase of H. pylori infection (P=0.0001) in GERD patients than control group. HLA-DRB1* 15:01 was significantly increased in GERD patients in comparison with control group and an increased frequency of HLADRB1*11:01 in control group compared with patients group.

CONCLUSION

- There is an association between HLA-DRB1 *15:01 in GERD patients with H. pylori positive patients.

A novel approach for HLA-A typing in formalin-fixed paraffin-embedded-derived DNA

The aim of this study was to establish a novel approach for human leukocyte antigen (HLA)-typing from formalin-fixed paraffin-embedded-derived DNA. HLAs can be a prognostic factor in cancer and have an extensive polymorphism. This polymorphism is predominantly restricted to exons, which encode the peptide-binding domain of the protein. Formalin-fixed paraffin-embedded material is routinely collected in the clinic and therefore a great source of DNA for genetic analyses. However, its low quality due to fragmentation and nucleotide changes has often created obstacles in designing genetic assays. In this study, we amplified the most polymorphic exons of the HLA-A gene, exons 2, 3, and 4, in 16 formalin-fixed paraffin-embedded samples >10 years old. These tissue samples belonged to patients already HLA-typed by peripheral blood samples at the routine laboratory. Acquired amplification products were used for sequencing, which provided enough information to establish an HLA allele. The same method was applied to DNA extracted from peripheral blood from a healthy volunteer with known HLA type. Of the samples, 14/16 (88%) were successfully typed, in one sample only one of the alleles could be determined, and in one sample no allele could be determined. The amplification of the most polymorphic exons of HLA-A was a successful alternative when DNA quality prevented positive results with previously described methods. The method is usable when an HLA type is needed but the patients are deceased and/or no whole blood samples can be collected. It has thus potential to be used in several fields such as the clinic, research, and forensic science.

Treatment failure in patients with HPV 16-induced vulvar intraepithelial neoplasia: understanding different clinical responses to immunotherapy

Failure of the immune system to launch a strong and effective immune response to high-risk HPV is related to viral persistence and the development of anogenital (pre)malignant lesions such as vulvar intraepithelial neoplasia (VIN). Different forms of immunotherapy, aimed at overcoming the inertia of the immune system, have been developed and met with clinical success. Unfortunately these, in principal successful, therapeutic approaches also fail to induce clinical responses in a substantial number of cases. In this review, the authors summarize the traits of the immune response to HPV in healthy individuals and in patients with HPV-induced neoplasia. The potential mechanisms involved in the escape of HPV-induced lesions from the immune system indicate gaps in our knowledge. Finally, the interaction between the immune system and VIN is discussed with a special focus on the different forms of immunotherapy applied to treat VIN and the potential causes of therapy failure. The authors conclude that there are a number of pre-existing conditions that determine the patients' responsiveness to immunotherapy. An immunotherapeutic strategy in which different aspects of immune failure are attacked by complementary approaches, will improve the clinical response rate.

HLA-A and breast cancer in West Peninsular Malaysia

Breast cancer is the most common malignancy among females in Malaysia. Attempts have been made to investigate the association between breast cancer and human leukocyte antigen (HLA) types. However, data from those previous studies are highly variable. The aim of this study is to investigate the association between HLA-A types and clinicopathological factors in breast cancer. The frequencies of HLA-A type in 59 female patients with infiltrating ductal of the breast were determined by polymerase chain reaction method. HLA-A2/A30 and A2/A31 haplotype (5.1%; P = 0.045) as well as HLA-A30 (5.1%, P = 0.045) and A31 (6.8%; P = 0.020) allele were significant higher in the patients than controls (0%). HLA-A24 allele was negatively related to lymph node metastasis (r = -0.316; P = 0.021) whereas, A26 (r = -0.430; P = 0.001) and A36 (r = -0.430; P = 0.001) alleles were negatively correlated to distant metastasis in breast cancer. Negative correlations between HLA-A26/A36 (r = -0.430; P = 0.001), A2/A11 (r = -0.276; P = 0.044), A24/A34 (r = -0.430; P = 0.001) haplotypes and distant metastasis were identified. Interestingly, Her2 expression in breast carcinoma was negatively correlated to A11/24 haplotypes (r = -0.294; P = 0.034) but positively correlated to homozygous HLA-A24 (r = 0.396; P = 0.040). In conclusion, HLA-A2, -A30 and A31 were associated with breast cancer.

Association of human leukocyte antigen and esophageal cancer in North of Iran

Several risk factors including environmental factor, Genetic and nutritional deficiencies have been associated with Esophageal Cancer (EC) in high risk areas. In a case-control association study, the association of HLA class I and esophageal carcinoma has been investigated. A total number of 30 patients and 30 clinical healthy individuals matched for sex and age with the same ethnicity and residence status were enrolled. Five milliliter defibrinated blood taken from each individual and diluted 1:1 with Hanks balanced salt solution buffer. The diluted blood added to 3.0 mL separating medium (ficol hypaqe). Lymphocyte separated and HLA, A, B and C molecules were determined by using the Terrasaki Mirocytotoxicity test. Data were analyzed by Chi square and Fisher exact tests. Thirty patients (20 females and 10 males) with age 61 +/- 2.4 enrolled in this study. Only patients with definite diagnosis of Squamous Cell Carcinoma (SCC) included and Patients with other esophageal cancer (adenocarcinoma) excluded. The frequency of many HLA molecules were different in comparison of patients and control groups, but statistical analysis of the data revealed that only difference between frequency of HLA A11, B41 and Cw3 are significant (p<0.05). We concluded that HLA-A11, -B41 and -Cw3 molecules may be risk factors for esophageal cancer in northern part of Iran.

Clinical significance of HLA class I alleles on postoperative prognosis of lung cancer patients in Japan

BACKGROUND

The role of the HLA phenotype in cancer prognosis has been frequently discussed. We previously reported the correlation between HLA alleles and the postoperative prognosis of 204 patients with non-small cell lung cancer (NSCLC). The present study was based on 695 patients with NSCLC to confirm these correlations.

METHODS

We evaluated the medical records of 695 NSCLC patients who underwent surgical resection. The serological typing of HLA class I was performed using a microcytotoxicity test of lymphocytes or PCR-sequence-specific oligonucleotides (PCR-SSO), and the correlation between the HLA alleles and the clinicopathological features was analyzed. The survival curves were calculated, and then a comparison of the survival curves was carried out.

RESULTS

The HLA-A2 positive(A2(+)) group at stage I showed a more unfavorable prognosis than HLA-A2(-) group in overall survival. At stage II+III, the HLA-A24(+) group had a poorer prognosis than the HLA-A24(-) group, and the HLA-B52(+) group showed unfavorable prognosis. Multivariate analysis demonstrated that HLA-A2 at stage I and HLA-A24 at stage II+III were the independent factors that affected the survival period.

CONCLUSIONS

The expression of HLA-A2 was considered as one of the unfavorable prognostic factors in the NSCLC patients at stage I. HLA-A24(+) group showed a significant unfavorable prognosis at stage II+III. These results suggested that HLA-A2 and HLA-A24 could be the prognostic factors in patients with NSCLC according to the state of advancement of the disease.

Loss of human leucocyte antigen class I and gain of class II expression are early events in carcinogenesis: clues from a study of Barrett's oesophagus

BACKGROUND

Human leucocyte antigen (HLA) expression is altered in oesophageal carcinomas compared with normal tissue. It is unclear, however, whether this phenotype precedes malignant transformation or results as a consequence of it.

AIM

To investigate HLA class I and II expression in Barrett's oesophagus and normal squamous oesophageal tissue.

METHODS

Asian patients with Barrett's oesophagus (n = 64) and a control group (n = 60) with a normal oesophagus but without reflux symptoms were recruited using endoscopic and histopathological criteria. Tissue samples were stained with monoclonal antibodies specific for HLA-ABC, HLA-DR alpha chain or HLA-DP/DQ/DR, and scored semiquantitatively. The results of immunohistochemical staining were correlated with clinical and histopathological characteristics of patients.

RESULTS

Marked expression of HLA-ABC was observed in 50% of Barrett's oesophagus sections as compared with 68.3% of controls (p = 0.038). HLA-DR staining was seen in 51.6% of Barrett's oesophagus samples versus 11.7% of controls (p<0.001). Expression of HLA-DP/DQ/DR was evident in 73.4% of oesophageal intestinal metaplasia tissue as opposed to 18.3% of controls (p<0.001). Importantly, a total loss of HLA-ABC and a concomitant gain of HLA-DP/DQ/DR expression were seen in 37.5% of patients with Barrett's oesophagus but in none of the controls (p<0.001). Interestingly, this phenotype was associated positively with dysplasia (adjusted p, p* = 0.031) but negatively with non-steroidal anti-inflammatory drug use (p* = 0.004).

CONCLUSIONS

HLA class I expression is down regulated and class II expression is up regulated in Barrett's oesophagus. As these changes predate malignant transformation, altered major histocompatibility complex expression may be a key event in disease progression, possibly in facilitating evasion from immune surveillance.

Human leucocyte antigen determinants of susceptibility to Barrett's oesophagus in Asians--a preliminary study

BACKGROUND

Characteristic immune profiles have been demonstrated in gastro-oesophageal reflux disease. However, the genetic basis of gastro-oesophageal reflux disease remains unclear.

AIM

To investigate whether certain human leucocyte antigen genes are associated with Barrett's oesophagus.

METHODS

Asian patients of Malay, Chinese and Indian descent with Barrett's oesophagus (n = 59) and those without reflux symptoms and a normal oesophagus (n =60) were recruited prospectively using endoscopic and histopathological criteria. Human leucocyte antigen class I and II typing was performed using a polymerase chain reaction sequence-specific primers method.

RESULTS

The HLA-B7 allele was present in 17% (10 of 59) of patients with Barrett's oesophagus when compared with 0% (zero of 60) of controls [P = 0.0006, corrected P = 0.0171, OR = 25.67]. Subgroup analysis revealed that the HLA-B7 allele was confined almost exclusively to Indians with Barrett's oesophagus, 43% (nine of 21) vs. 0% (zero of 19) Indian controls (P = 0.0014, corrected P = 0.0406, OR = 29.64). No class II associations, protective human leucocyte antigens or extended haplotypes for disease susceptibility were identified.

CONCLUSIONS

Barrett's oesophagus in Asians, particularly Indians, is strongly positively associated with HLA-B7; reinforcing a genetic component to gastro-oesophageal reflux disease. A larger sample size and different ethnic populations should be genotyped to further confirm this association and identify possible additional risk factors in the human leucocyte antigen locus.

Immune control of human papillomavirus (HPV) associated anogenital disease and potential for vaccination

This review discusses: (1) immune mechanisms relevant to the natural control of a human papillomavirus (HPV) infection; (2) viral strategies to evade or subvert immune attack; (3) the significance of immune escape as a feature of the evolution of invasive cancer; (4) vaccine strategies for prevention and/or therapy. HPV infection and associated malignancy can induce humoral and cellular immunity to capsid and oncogene viral proteins, but it is not always clear whether such responses are a consequence of the disease rather than the resolving factor(s). Prophylactic strategies are utilising virus-like particles (VLP) composed of the L1 viral capsid protein to induce neutralising antibodies, while therapeutic approaches are aimed at generating specific T cells targeted at the viral E6 and/or E7 oncogenes. Thus far, HPV VLP vaccines have proved clinically efficacious in the early clinical trials to prevent infection. Different types of therapeutic vaccines including peptide, protein, DNA or viral vector encoded have proved safe and immunogenic in patients, although there is often no correlation with clinical outcome. Understanding the equilibrium between viral and immunological factors will be important in providing the appropriate tools to evoke effective prophylactic and therapeutic immunity. It seems likely that combined prophylactic and therapeutic vaccine approaches could offer the best prospect for any significant reduction in death from cervical cancer worldwide.

Perspectives on cancer immuno-epidemiology

Estimating human cancer risk based on host-environment interaction is one task of epidemiology, and it has provided indispensable knowledge for prevention of cancer. The recent develop-ment of gene-engineered mice has also provided solid evidence about the relationship between cancer development and immunity. The aim of this review is to discuss the possible contribution of epidemiology to understanding the role of immunity in host defense against cancer, and also to assess the involvement of inflammation in the occurrence of selected cancers. Here we look at the concepts of cancer immunosurveillance and infection-inflammation-cancer, and include a brief introduction to recent studies in humans and experimental animal models. It has been postulated for many years that the immune system has the ability to recognize and eliminate nascent transformed cells in the body (so-called cancer immunosurveillance hypothesis), and this idea has recently obtained strong support from animal experiments. In humans, follow-up studies among immunosuppressed transplant recipients revealed a remarkably increased risk of not only selected malignancies, but also cancers with no known viral etiology. On the other hand, a prospective cohort study among the general population revealed that individuals with low natural cytotoxic activity of peripheral blood lymphocytes had an increased risk of cancer development. More studies are warranted to allow the construction of a model for the interaction between host immunity, aging, and the environment. The host immune system is also involved in inflammatory responses to pathogen infection: insufficient immune function of the host, or repeated infection, may result in persistent inflammation, where growth/survival factors continuously act on initiated cells. The combined use of biomarkers will be necessary to define low-grade persistent inflammation in future cohort studies; and, in addition to these phenotype marker-based cohort studies, one plausible future direction will be a genomic approach that can be undertaken within cohort studies, looking at the genetic background underlying individual variations in phenotype markers.

Genetic susceptibility to breast cancer: HLA DQB*03032 and HLA DRB1*11 may represent protective alleles

Tumors are believed to emerge only when immune surveillance fails. We wished to ascertain whether the failure to inherit putative protective alleles of HLA class II genes is linked to the development of breast cancer. We molecularly typed HLA DPB1, DQB1, DRB1, and DRB3 alleles in 176 Caucasian women diagnosed with early-onset breast cancer and in 215 ethnically matched controls. HLA DQB*03032 was identified in 7% of controls but in no patients with early-onset breast cancer (P = 0.0001). HLA DRB1*11 alleles were also significantly overrepresented (P < 0.0001) in controls (16. 3%) as compared with patients with early-onset breast cancer (3.5%). HLA DQB*03032 and HLA DRB1*11 alleles may have a protective role in human breast cancer.