Expression of nonclassical molecule human leukocyte antigen-G in oral lesions

Human papillomavirus prevalence in oral and oropharyngeal squamous cell carcinoma in South America

Some studies have addressed the prevalence of human papillomavirus (HPV) in head and neck cancer in South America; however, no studies have systematically gathered prevalence and conducted a meta-analysis. This study aims to estimate the prevalence of HPV in oral and oropharyngeal squamous cell carcinomas in South America. We performed a systematic review and metaanalysis using the following databases: PubMed, Embase, Lilacs, Medline, Scopus, and Web of Science. Data were extracted and analyzed using random-effects models to estimate the pooled prevalence of HPV. We identified 209 nonduplicated studies, of which 38 were selected. The overall prevalence of HPV was 24.31% (95% CI 16.87–32.64; I² = 96%, p_{heterogeneity} <0.001). HPV prevalence in oropharyngeal cancer was 17.9% (95% CI 7.6–31.4; I² = 96%, p_{heterogeneity} <0.001) and that in oral cavity cancer was 23.19% (95% CI 14.94–32.63; I² = 94%, p_{heterogeneity} <0.001). We found an overall prevalence of HPV in 24.31% of oral and oropharyngeal squamous cell carcinomas in South American patients. The prevalence of HPV was 17.9% for oropharyngeal cancer and 23.19% for oral cavity cancer.

The head and neck cancer genome in the era of immunotherapy

The recent success of immunotherapy in head and neck squamous cell carcinoma (HNSCC) has necessitated a new perspective on the cancer genome. Here we review recent advances in the carcinogenesis and molecular genetics of HNSCC with an eye on their implications for cancer immunity. Newer sequencing technologies have recently facilitated dissection of the complex interaction between the HPV virus, tumor, host factors, and the tumor microenvironment (TME) that help shed light on how the immune system interacts with head and neck malignancies.

The Double-Edged Sword-How Human Papillomaviruses Interact With Immunity in Head and Neck Cancer

Patients with human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) have remarkably better prognosis, which differs from HPV-negative oropharyngeal squamous cell carcinoma (OPSCC) with respect to clinical, genomic, molecular, and immunological aspects, especially having the characteristics of high levels of immune cell infiltration and high degrees of immunosuppression. This review will summarize immune evasion mechanisms in HPV-positive HNSCC, analyze the host various immune responses to HPV and abundant numbers of infiltrating immune cell, and discuss the differences between HPV-positive HNSCC with cervical cancer. A deeper understanding of the immune landscape will help new concepts to emerge in immune-checkpoint oncology, which might be a valuable add-on to established concepts.

Individual heavy metal exposure and birth outcomes in Shenqiu county along the Huai River Basin in China

Background: Exposure to heavy metals during pregnancy is an important risk factor for adverse birth outcomes. We aimed to investigate the current heavy metal exposure levels in cord blood from healthy pregnant women residing in the Huaihe River Basin, China, and examined the association between heavy metal levels and dietary habits and lifestyle factors. In this study, we measured the exposure levels of five heavy metals in the umbilical cord blood from 350 healthy pregnant women and administered 350 self-reported questionnaires regarding the general characteristics and dietary habits of those women. Methods: This study was undertaken in Shenqiu county, Henan province, which is in the area of the Huai River Basin, in a cohort of pregnant women and newborn babies in 2013-2014. We recruited a sample of 1000 pregnant women among those receiving prenatal examination, measured the real individual newborn exposure to heavy metals in serum by ICP-MS, collected information regarding the pregnant women with a questionnaire survey and obtained data on environmental quality from environmental protection agencies and the available literature. We estimated the daily individual exposure to heavy metals of all the 1000 participants throughout the pregnancy and recorded their birth outcomes after delivery. Then we analyzed the association between birth outcome and individual exposure to heavy metals. Results: 54 newborn children had birth defects. The geometric means of cord blood levels of As, Cd, Cr, Pb and Hg were measured at 0.92 ± 1.01 ng mL-1, 0.11 ± 0.17 ng mL-1, 4.57 ± 5.02 ng mL-1, 3.37 ± 3.81 ng mL-1 and 0.89 ± 1.69 ng mL-1 for subjects (n = 54) who gave birth to infants with birth defects and 0.43 ± 0.88 ng mL-1, 0.52 ± 3.86 ng mL-1, 1.94 ± 2.92 ng mL-1, 4.38 ± 4.96 ng mL-1 and 0.43 ± 0.91 ng mL-1 for subjects (n = 296) with healthy infants, respectively. The contents of all five heavy metals in the whole blood of both of these two groups were higher than the reference values of the Chinese general population (P < 0.001). Conclusions: The occurrence of birth defects was 15.4% in this cohort, and was correlated to exposure of parents to environments containing heavy metal contaminants in Shenqiu county in the Huai River Basin. The heavy metal exposure situation of the investigated population had serious effects in terms of reproductive defects in children. The specific link between newborn defects and environmental heavy metal contaminants suggested that contamination in pregnant women persisted over time, and that the exposure may have a long term effect.

Immunohistochemical investigations on the expression of programmed cell death ligand 1, human leukocyte antigens G and E, and granzyme B in intraoral mucoepidermoid carcinoma

OBJECTIVE

To identify the expression of nonclassical human leukocyte antigen G and E (HLA-G and -E), programmed cell death ligand-1 (PD-L1) and granzyme B (GB) in intraoral mucoepidermoid carcinomas (MECs), and to assess whether such expressions are related to metastasis, survival, staging, tumor grade and number of GB-positive cells.

DESIGN

For this cross-sectional study, samples of MEC (n=30) were selected and classified as low-grade (LG), intermediate-grade (IG) or high-grade (HG), according to the WHO grading system. HLA-G, -E and PD-L1 were identified by immunohistochemistry and quantified as the proportion of positive neoplastic cells. The density of GB+ cells was also evaluated. The Kruskal-Wallis test was used with a 5% significance level.

RESULTS

Expressions of HLA-G, -E and PD-L1 were identified in the majority of epidermoid, intermediate and clear cells, but not in the mucous cells of the MECs. The quantitative analysis of the total percentage of positive neoplastic cells showed overexpression of this set of proteins in all MEC samples. The expression of these proteins and histological grading were positively correlated [HLA-G (LG=79% positive cells, IG=96%, HG=99%; p=0.0004), HLA-E (LG=70%, IG=96%, HG=99%; p<0.0001) and PD-L1 (LG=34%, IG=79%, HG=80%; p=0.01)]. No relationship was observed between the immunosuppressive proteins and other clinicopathological parameters. Low GB density was found in all MEC samples.

CONCLUSIONS

The augmented expression of HLA-G, -E and PD-L1 in the intraoral MEC might suggest a role of these molecules in the scape of neoplastic cells from immunosurveillance.

Overexpression of immunomodulatory mediators in oral precancerous lesions

Human leukocyte antigen (HLA) G and E, programmed cell death 1 ligand 1 (PD-L1), IL-10 and TGF-β are proteins involved in failure of the antitumor immune response. We investigated the expression of these immunomodulatory mediators in oral precancerous lesions (oral leukoplakia-OL; n=80) and whether these molecules were related to the risk of malignant transformation. Samples of normal mucosa (n=20) and oral squamous cells carcinoma (OSCC, n=20) were included as controls. Tissue and saliva samples were analyzed by immunohistochemistry and ELISA respectively. Fifteen OL samples showed severe dysplasia (18.7%) and 40 samples (50%) presented combined high Ki-67/p53. Irrespective of the degree of epithelial dysplasia and the proliferation/apoptosis index of OL, the expression of HLA-G, -E, PD-L1, IL-10, TGF-β2 and -β3 was higher to control (P<0.05) and similar to OSCC (P>0.05). The number of granzyme B+ cells in OL was similar to control (P=0.28) and lower compared to OSCC (P<0.01). Salivary concentrations of sHLA-G, IL-10 and TGF-β did not allow for a distinction between OL and healthy individuals. Overexpression of immunosuppressive mediators in the OL reflects the immune evasion potential of this lesion, which is apparently independent of at cytological and proliferation/apoptosis status.

Prevalence of oral and oropharyngeal human papillomavirus infection in Brazilian population studies: a systematic review

Introduction

Human papillomavirus has been associated with head and neck squamous cell carcinoma. However, there is no conclusive evidence on the prevalence of oral or pharyngeal infection by human papillomavirus in the Brazilian population.

Objective

To determine the rate of human papillomavirus infection in the Brazilian population.

Methods

Systematic review of published articles. Medline, The Cochrane Library, Embase, Lilacs (Latin American and Caribbean Health Sciences) and Scielo electronic databases were searched. The search included published articles up to December 2014 in Portuguese, Spanish and English. A wide search strategy was employed in order to avoid publication biases and to assess studies dealing only with oral and/or oropharyngeal human papillomavirus infections in the Brazilian population.

Results

The 42 selected articles enrolled 4066 patients. It was observed that oral or oropharyngeal human papillomavirus infections were identified in 738 patients (18.2%; IC 95 17.6–18.8), varying between 0.0% and 91.9%. The prevalences of oral or oropharyngeal human papillomavirus infections were respectively 6.2%, 44.6%, 44.4%, 27.4%, 38.5% and 11.9% for healthy people, those with benign oral lesions, pre-malignant lesions, oral or oropharyngeal squamous cell carcinoma, risk groups (patients with genital human papillomavirus lesions or infected partners) and immunocompromised patients. The risk of human papillomavirus infection was estimated for each subgroup and it was evident that, when compared to the healthy population, the risk of human papillomavirus infection was approximately 1.5–9.0 times higher, especially in patients with an immunodeficiency, oral lesions and squamous cell carcinoma. The rates of the most well-known oncogenic types (human papillomavirus 16 and/or 18) also show this increased risk.

Conclusions

Globally, the Brazilian healthy population has a very low oral human papillomavirus infection rate. Other groups, such as at-risk patients or their partners, immunocompromised patients, people with oral lesions and patients with oral cavity or oropharyngeal squamous cell carcinoma have a high risk of human papillomavirus infection.

The clinicopathologic significance of the expression of HLA-G in oral squamous cell carcinoma

OBJECTIVE

This study aimed to evaluate HLA-G expression in primary oral cavity squamous cell carcinoma (OCSCC) and potentially malignant lesions and to evaluate its relationship with clinicopathologic parameters.

STUDY DESIGN

HLA-G expression in samples from patients with metastatic and nonmetastatic OCSCC (n = 60), potentially malignant lesions (n = 15), and clinically and histologically normal oral mucosa (n = 10) was characterized by immunohistochemistry. The density of CD8, CD83, and CD68 cells and Ki-67(+) and bcl-2(+) neoplastic cells were analyzed.

RESULTS

HLA-G expression by neoplastic cells was significantly higher in metastatic OCSCC compared with nonmetastatic OCSCC (P = .01). Higher HLA-G expression was observed in OCSCC than in potentially malignant lesions (P = .006). Moreover, patients with lower HLA-G expression exhibited a tendency toward longer survival (22 months) compared with those with higher HLA-G expression (16 months).

CONCLUSIONS

Our findings suggest that increased HLA-G expression in metastatic OCSCC may represent a tumor escape mechanism, which portends an unfavorable clinical prognosis.

The association between human leukocyte antigen (HLA)-G polymorphisms and human papillomavirus (HPV) infection in Inuit women of northern Quebec

BACKGROUND

The human leukocyte antigen (HLA)-G molecules act as negative regulators of the immune response. We analyzed the associations between HLA G polymorphisms and human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) in Inuit women from Nunavik, northern Quebec.

METHODS

Cervical specimens from a cohort study of 548 Inuit women were tested for HPV DNA. HPV genotypes were classified according to tissue-tropism groupings of alpha-papillomavirus species: alpha group 1 includes low risk (LR) cervical species, group 2 includes high risk (HR) cervical species, and group 3 includes LR vaginal species. HLA-G alleles were typed using direct DNA sequencing.

RESULTS

HLA-G(∗)01:01:01 was associated with an increased risk of period prevalent alpha groups 1 (OR = 2.23, 95% CI:1.08-4.59) and 3 (OR = 1.70, 95% CI:1.09-2.65). The homozygous HLA-G(∗)01:04:01 genotype was associated with a decreased risk of alpha group 3 infection period prevalence (OR = 1.69 95% CI = 1.07-2.67). No HLA-G alleles were significantly associated with HPV persistence. HLA-G(∗)01:01:02, G(∗)01:04:01 and G(∗)01:06 were associated with high grade (HG)SIL, but the association did not reach statistical significance.

CONCLUSIONS

These results suggest that HLA-G polymorphisms play a role in the natural history of HPV infection, likely at the stage of host immune recognition. HLA-G polymorphisms interacted differently with the three alpha papillomavirus groups.

Barriers of the Human Organism and Their Achilles’ Heels

The human body is covered by barriers separating it from the external and internal surroundings. The “milieu enterieur” has to be stabilised in spite of the variable external and internal conditions of toxic, osmotic, microbial and climatic environmental circumstances. This first line of barriers is composed of skin and mucous membranes of complicated structures.

A second line of barrier system is present in our organisms. Certain organs have to be separated from the immune system and other parts of the body because of evolutionary reasons (eye-bulb and testicles) because of unique proteins “unknown” for the acquired immune system. The blood-brain barrier (BBB) is providing enhanced safety circumstances for the central nervous system. The second line of barriers is represented by the special properties of the capillary endothelial system.

The maternal-fetal barrier is the most complex. At the maternal fetal interface two individuals of two different haplotypes has to be live 9 months separated by a very complicated dynamic barrier.

The placenta is the organ, which is separating the maternal and fetal tissues. Similar to others the bidirectional transport of gasses, metabolites, cells, proteins, regulatory substances, are transported by active or passive transcellular and intercellular mechanisms.

The fetal immune system develops immunotolerance to all maternal cells and antigens transferred transplacentally. The problem is to mitigate the maternal immune system to tolerate the paternal haplotype of the fetus. In the case of normal pregnancy a complex series of physiological modifications can solve the problem without harmful consequences to the mother and fetus.

The outermost contact cells of trophoblasts express instead of HLA-class Ia and class II antigens non-variable HLA-C, HLA-E, HLA-F and HLA-G antigens. The first consequence of this is reduction of the activity of maternal natural killer cells and maternal dendritic cells;

Progesteron, micro-RNA and mediators influence the development of T effector-cells. The production of soluble HLA-G(5 and 6) and IL-10 supports the differentiation of Th-2 CD4⁺ helper cells, reducing the ability of maternal cells to kill fetal cells.

Series of receptors and costimulators are expressed by the different lines of semi-allogenic trophoblast cells to bind HLA-G and mitigate maternal immune response;

The maternal immunotolerance is further facilitated by the activation of CD4⁺CD25^brightFoxp3⁺ regulatory T (T_REG) cells.

Infections have to be prevented during pregnancy. The cells of placenta express 10 Toll-like receptors a group of pattern recognition receptors responsible for innate immunity. The interferon level is also higher in the placental tissues than in the somatic fetal or maternal cells.

The complement system is also adapted to the requirements of the pregnancy and fetal damage is inhibited by the production of “assymmetric IgG antibodies” under hormonal and placental-regulation. These modifications prevent the activation of complement, cytotoxic activity, opsonising ability, antigen clearance and precipitating activity of the molecules.

The Achilles’ heels of the different barriers are regularly found by virus infections. Lamina cribrosa of the blood-brain barrier, optical nerve of the eyes, etc. the risk factors of the maternal-fetal barrier has been summarised in Table 1.1.