Genetic Variant of DNAM-1 rs763361 C>T Is Associated with Ankylosing Spondylitis in a Mexican Population.

DNAM-1 (CD226) is an activating receptor expressed in CD8+ T cells, NK cells, and monocytes. It has been reported that two SNPs in the DNAM-1 gene, rs763361 C>T and rs727088 G>A, have been associated with different autoimmune diseases; however, the role of DNAM-1 in ankylosing spondylitis has been less studied. For this reason, we focused on the study of these two SNPs in association with ankylosing spondylitis. For this, 34 patients and 70 controls were analyzed using endpoint PCR with allele-specific primers. Our results suggest that rs763361 C>T is involved as a possible protective factor under the CT co-dominant model (OR = 0.34, 95% CI = 0.13-0.88, p = 0.022) and the CT + TT dominant model (OR = 0.39, 95% CI = 0.17-0.90, p = 0.025), while rs727088 G>A did not show an association with the disease in any of the inheritance models. When analyzing the relationships of the haplotypes, we found that the T + A haplotype (OR = 0.31, 95% CI = 0.13-0.73, p = 0.0083) is a protective factor for developing the disease. In conclusion, the CT and CT + TT variants of rs763361 C>T and the T + A haplotype were considered as protective factors for developing ankylosing spondylitis.

Low-diversity microbiota and an increased metabolism of arginine and aromatic amino acids: a hallmark of hepatic encephalopathy in western Mexican patients with alcohol-associated cirrhosis.

AIMS: To evaluate the composition and functions of the gut microbiota in patients with decompensated alcohol-associated cirrhosis, with and without hepatic encephalopathy (HE). METHODS AND RESULTS: Faecal samples from 31 inpatients (20 with HE, 11 without HE), and from 18 age-balanced healthy controls (HC), were included. Microbial composition was determined by 16S rRNA amplicon sequencing and analysed using QIIME2. Metabolic pathways were inferred by PICRUSt2, and short-chain fatty acids (SCFAs) quantification was performed by gas chromatography. The gut microbiota of patients with HE was characterized by a diminished α-diversity, compared to no-HE (P < 0.01) and HC (P < 0.001) groups; ß-diversity also differed between HE vs no-HE patients (P < 0.05), and between HE vs HC (P < 0.001). In patients with HE, Escherichia/Shigella, Burkholderiales and Lactobacillales taxa predominated. In contrast, patients without HE were characterized by Veillonella and Bacteroides. Reduced levels of faecal SCFAs in both groups correlated with a depletion of beneficial taxa, such as Ruminococcus or Faecalibacterium. PICRUSt2 analysis showed both an enhanced catabolism of arginine through ammonia-producing pathways and chorismate biosynthesis in HE patients, a key precursor of aromatic amino acids. CONCLUSIONS: The gut microbiota of HE patients exhibits a proinflammatory dysbiotic profile, plus metabolic pathways that produce potentially neurotoxic byproducts.

A Modified Method for the Quantification of Immune Checkpoint Ligands on Exosomes from Human Serum using Flow Cytometry.

Objectives: Exosomes are the smallest of the extracellular vesicles and can contain a variety of different cargos, including nucleic acids, lipids, and proteins. Ultracentrifugation followed by electron microscopy has historically been used for the isolation and visualization of exosomes; Western blot and ELISA have also been used, but these techniques are only semiquantitative and are unable to distinguish different exosome markers in the same sample. To resolve some of these issues, we propose a modification of a bead-based flow cytometry method. Methods: Peripheral blood serum was mixed with a commercial exosome separation reagent and incubated for 30 min at 4°, centrifuged, exosome pellet was isolated and resuspended in PBS. Exosomes were then added to magnetic beads, incubated 18 h, then incubated with exosome-specific antibodies for 1 h. The resulting bead:exosome complexes were centrifuged and then washed, then washed again using a magnetic separator, resuspended in PBS, and analyzed via flow cytometry. Results: Using commercial magnetic beads bound with anti-CD63, our protocol modifies starting conditions, washing steps, and magnetic separation and uses the FSC and SSC determination of the flow cytometer to result in increased yield and identification of the exosome populations of interest. Our modified protocol increased the yield of specific populations approximately 10-fold. Conclusion: The new protocol was used to identify exosomes positive for 2 immune checkpoint ligands in serum-derived exosomes from cervical cancer patients. We suspect that this protocol can also be used for the identification of other exosome proteins since we also quantified the exosome membrane-enriched tetraspanins CD9 and CD81. Identification of proteins rarely expressed in exosomes is complicated in this technique as serum is an inherently dirty source of exosomes, and great care must be taken in the washing and gating of the exosome:bead populations.

Non-fitness status of peripheral NK cells defined by decreased NKp30 and perforin, and increased soluble B7H6, in cervical cancer patients.

The NKp30 receptor is one of the three natural cytotoxic receptors reported in NK cells. This receptor is codified by the NCR3 gene, which encodes three isoforms, a consequence of the alternative splicing of exon 4. A greater expression of the three isoforms (A, B, and C), along with low levels of the NKp30 ligand B7H6, has been reported as a positive prognostic factor in different cancer types. Here, in patients with cervical cancer and precursor lesions, we report an altered immune-phenotype, characterized by non-fitness markers, that correlated with increased disease stage, from CIN 1 to FIGO IV. While overall NK cell numbers increased, loss of NKp30+ NK cells, especially in the CD56dim subpopulation, was found. Perforin levels were decreased in these cells. Decreased expression of the NKp30 C isoform and overexpression of soluble B7H6 was found in cervical cancer patients when compared against healthy subjects. PBMCs from healthy subjects downregulated NKp30 isoforms after co-culture with B7H6-expressing tumour cells. Taken together, these findings describe a unique down-modulation or non-fitness status of the immune response in cervical cancer, the understanding of which will be important for the design of novel immunotherapies against this disease.

Nanobodies as efficient drug-carriers: Progress and trends in chemotherapy.

Nanobodies (Nb) have a promising future as a part of next generation chemodrug delivery systems. Nb, or VHH, are small (15 kDa) monomeric antibody fragments consisting of the antigen binding region of heavy chain antibodies. Heavy chain antibodies are naturally produced by camelids, however the structure of their VHH regions can be readily reproduced in industrial expression systems, such as bacteria or yeast. Due to their small size, high solubility, remarkable stability, manipulatable characteristics, excellent in vivo tissue penetration, conjugation advantages, and ease of production, Nb have many advantages when compared against their antibody precursors. In this review, we discuss the generation and selection of Nbs via phage display libraries for easy screening, and the conjugation techniques involved in creating target-specific nanocarriers. Furthermore, we provide a comprehensive overview of recent developments and perspectives in the field of Nb drug conjugates (NDCs) and Nb-based drug vehicles (NDv) with respect to antitumor therapeutics.

Anti-fouling SERS-based immunosensor for point-of-care detection of the B7-H6 tumor biomarker in cervical cancer patient serum.

Herein, we report the development of sandwich type Surface Enhanced Raman Spectroscopy (SERS) immunosensor modified to be zwitterionic for the detection of soluble B7-H6 biomarker in blood serum from cervical cancer patients. Anti-fouling capture SERS substrate of biosensor based on gold (Au) thin film was modified with a self-assembled monolayer of zwitterionic l-cysteine to combat serum fouling and was then conjugated with NKp30 receptor protein to capture the B7-H6 biomarker in blood serum. The SERS nanoprobe based on spiky gold nanoparticles (AuNPs) was functionalized with ATP reporter molecule, that is stable at a wide range of pH, making the SERS signal reliable in complex media. Then, it was conjugated with anti-B7-H6 antibody forming the complex anti-B7-H6@ATP@AuNPs (i.e., SERS nanoprobe). The proposed immunosensor demonstrated high reproducibility for the quantitative detection of soluble tumor biomarker B7-H6 within the range of 10-10 M to 10-14 M with limit of detection (LOD) of 10-14 M or 10.8 fg mL-1, in the cancer patient serum, greatly exceeding (100 fold) the LOD of commercially available ELISA kits. Such low LOD is partially the result of zwitterionic modification which reduces the serum fouling by 55% compared to traditionally used BSA blocked capture substrates (i.e., control). Notably, this immunosensors demonstrated higher accuracy for detecting the B7-H6 biomarker in undiluted blood serum samples from cervical cancer patients and outperforms the currently available analytical techniques, making it reliable for point of care (POC) testing.

B7-H6, an immunoligand for the natural killer cell activating receptor NKp30, reveals inhibitory effects on cell proliferation and migration, but not apoptosis, in cervical cancer derived-cell lines.

BACKGROUND: Although great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored. METHODS: In this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy. RESULTS: Notably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression. CONCLUSIONS: Our results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future.

NK cells at the crossroads in COVID-19: a question of timing / Células NK en la encrucijada en COVID-19: una cuestión de tiempo

The outbreak of the novel coronavirus SARS-CoV-2 and the attendant physiological symptoms associated with the COVID-19 disease have led to an explosion of interest studying different aspects of the immune response. As of yet, the particular roles of natural killer cells are not well understood in this disease. NK cells are critical first-response cytotoxic cells of the innate immune system. NK cells are traditionally considered important for their roles in innate immunity against tumors and viral infected cells, as well as their ability to produce cytokines, particularly interferon-γ, and participate in antibody dependent cell cytotoxicity (ADCC). Here, we describe the role of NK cells in peripheral blood and in the lungs with respect to the pathology caused by SARS-CoV-2 and discuss the implications of proposed different types of therapies on NK cells. Evidence is accumulating that NK cells play an important role in initial surveillance as part of innate immunity. With the progression of the disease and rising inflammation, these cells, when in circulation, appear to become exhausted and ineffective. In the COVID lung, however, a complex interplay between inflammatory cells, chemokines, cytokines and aberrantly activated migratory NK cells occurs, potentiating local inflammation and the critical situation in the lungs.

El brote del nuevo coronavirus SARS-CoV-2 y los síntomas fisiológicos concomitantes asociados con la enfermedad COVID-19 han provocado una explosión de interés en la investigación de diferentes aspectos de la respuesta inmune. Hasta el momento, no se comprenden bien las funciones particulares de las células asesinas naturales (NK, por sus siglas en inglés: natural killer) en esta enfermedad. Las células NK son importantes células citotóxicas de primera línea que forman parte del sistema inmune innato. Las células NK se consideran tradicionalmente importantes por su papel en la inmunidad innata contra tumores y contra células infectadas por virus, así como por su capacidad para producir citoquinas y participar en la citotoxicidad celular dependiente de anticuerpos (ADCC, por sus siglas en inglés: antibody-dependent cell-mediated cytotoxicity). Aquí, se describe el papel de las células NK en sangre periférica y en pulmones con respecto a la nueva patología causada por SARS-CoV-2 y discute las implicaciones de los diferentes tipos de terapias propuestos con respecto a células NK. Al momento, diversos tipos de evidencia comienzan a revelar que las células NK podrían desempeñar un papel crucial en la vigilancia inicial contra el SARS-CoV-2. Con la progresión de la enfermedad y el aumento de la inflamación, estas células cuando están en circulación, parecen agotarse ("exhausted") y volverse ineficaces. En los pulmones de pacientes con COVID-19, sin embargo, se produce una interacción compleja entre células inflamatorias, quimioquinas, citoquinas y células NK migratorias activadas de manera aberrante, lo que potencia la inflamación local, contribuyendo a una situación más crítica a la función pulmonar.

Microbiome alterations are related to an imbalance of immune response and bacterial translocation in BDL-rats.

OBJECTIVES: Bacterial translocation in patients with cirrhosis is an important triggering factor for infections and mortality. In the bile duct ligation (BDL) model, crucial players of bacterial translocation are still unknown. This study aims to determine the interrelation between microbiome composition in the colon, mesenteric lymph nodes, and liver, as well as the local inflammatory microenvironment in the BDL model. MATERIALS AND METHODS: Liver damage was assayed by Masson trichrome staining, and hepatic enzymes. The diversity of microbiota in colon stools, mesenteric lymph nodes, and liver was determined by 16S rRNA pyrosequencing. Cytokine expression in mesenteric lymph nodes was analyzed by qRT-PCR. RESULTS: Our results show that Proteobacteria was the predominant phylum found to translocate to mesenteric lymph nodes and liver in cirrhotic rats. Bile duct ligation induces a drastic intestinal dysbiosis, revealed by an increased relative abundance of Sarcina, Clostridium, Helicobacter, Turicibacter, and Streptococcus genera. However, beneficial bacteria, such as Lactobacillus, Prevotella and Ruminococcus were found to be notably decreased in BDL groups. Mesenteric pro-inflammatory (TNF-α, IL-1ß, IL-6, TLR-4) and regulatory (TGF-ß, Foxp3, and IL-10) molecules at 30 days post-BDL were significantly increased. Conversely, TGF-ß and Foxp3 were significantly augmented at 8 days post-BDL. CONCLUSION: Dysbiosis in the colon and mesenteric lymph nodes is linked to an imbalance in the immune response; therefore, this may be an important trigger for bacterial translocation in the BDL model.

Differential effects of alliin and allicin on apoptosis and senescence in luminal A and triple-negative breast cancer: Caspase, ΔΨm, and pro-apoptotic gene involvement.

Breast cancer is the most frequent cancer in women worldwide, and drug resistance is common in all breast cancer types. The combination of natural products with chemotherapies has attracted attention, as it was found that natural compounds enhance the effects of standard cancer chemotherapeutic drugs and protect from side effects. Into the different natural products, garlic has been recognized for its antitumor properties. It is suggested that its anticancer effects are associated with its organo-sulfur compounds, especially alliin and allicin. Here, we evaluated the effects of both molecules on cell death, senescence, and their senolytic potential in luminal A and triple-negative breast cancer cells. MCF-7 (luminal A) and HCC-70 (triple-negative) cells were cultured and treated with different concentrations of alliin or allicin. Then, cell viability was determined using the WST-1 reagent. Apoptosis and caspase activity were evaluated by flow cytometry; ΔΨm was assessed using a JC-10 fluorometric assay kit. Apoptosis-related genes were evaluated by RT-PCR. Proliferation was measured using bromodeoxyuridine incorporation. We also evaluated clonogenicity, senescence (ß-Galactosidase Staining), and the senolytic effect of the compounds. Our results showed that allicin has antiproliferative, anticlonogenic, and senolytic effects. In addition, allicin decreased cell viability and induced apoptosis by loss of ΔΨm, caspase-3, caspase-8, and caspase-9 activation, upregulation of NOXA, P21, and BAK, as well as downregulation of BCL-XL expression. Contrary to allicin, alliin promoted clonogenicity, induced senescence, and did not exhibit pro-apoptotic effects in breast cancer cells.

Positive staining of the immunoligand B7-H6 in abnormal/transformed keratinocytes consistently accompanies the progression of cervical cancer.

BACKGROUND: B7-H6 has been revealed as an endogenous immunoligand expressed in a variety of tumors, but not expressed in healthy tissues. Heretofore, no studies have been reported describing B7-H6 in women with cervical cancer. To investigate this question, our present study was conducted. RESULTS: This retrospective study comprised a total of 62 paraffinized cervical biopsies, which were distributed in five groups: low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), squamous cervical carcinoma (SCC), uterine cervical adenocarcinoma (UCAC), and a group of cervicitis (as a control for non-abnormal/non-transformed cells). Cervical sections were stained by immunohistochemistry to explore the expression of B7-H6, which was reported according to the immunoreactive score (IRS) system. We observed a complete lack of B7-H6 in LSIL abnormal epithelial cells. Interestingly, B7-H6 began to be seen in HSIL abnormal epithelial cells; more than half of this group had B7-H6 positive cells, with staining characterized by a cytoplasmic and membranous pattern. B7-H6 in the SCC group was also seen in the majority of the sections, showing the same cytoplasmic and membranous pattern. Strong evidence of B7-H6 was notably found in UCAC tumor columnar cells (in 100% of the specimens, also with cytoplasmic and membranous pattern). Moreover, consistent B7-H6 staining was observed in infiltrating plasma cells in all groups. CONCLUSIONS: B7-H6 IRS positively correlated with disease stage in the development of cervical cancer; additionally, B7-H6 scores were found to be even higher in the more aggressive uterine cervical adenocarcinoma, suggesting a possible future therapeutic target for this cancer type.

Low-dose endosulfan inhibits proliferation and induces senescence and pro-inflammatory cytokine production in human lymphocytes, preferentially impacting cytotoxic cells.

Endosulfan is a DDT-era organochlorine pesticide. Due to past and current environmental contamination, investigation of endosulfan exposure is of current importance. Acute high dose exposure precipitates neural/endocrine system damage, but the effects on the immune system and of lower doses are not well-characterized. Two relatively low concentrations of endosulfan (i.e. 0.1 and 17 µM ENDO) were investigated in an in vitro study using human peripheral blood mononuclear cells (PBMC) to understand effects of relatively low doses (0.1-25.0 µM [≈0.04-10 ppm/40-10,000 ppb]) of ENDO upon normal human T- and B-lymphocytes and NK cells. The study here found that 17 µM ENDO inhibited phytohemagglutinin-M (PHA)-induced human PBMC proliferation. It was also seen that senescence and apoptosis among non-stimulated cells was increased, specifically within CD8 and NK populations, and that CD4:CD8 ratios also were increased. Treatment of non-stimulated PBMC with ENDO led to overall increases in production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, -4, and -6, and decreased production of anti-inflammatory IL-10, suggesting an immunosenescence secretory phenotype. Interestingly, when the cells were pre-stimulated with mitogen (PHA), ENDO became inhibitory against the mitogen-induced proliferation and cytokine formation - with the exception of that of TNFα and IL-6, suggesting differential effects of ENDO on activated cells. Thus, at the organismal level, ENDO might also display differential effects during states of autoimmune disease or chronic viral infection in the exposed host.

Bacterial Translocation Is Linked to Increased Intestinal IFN-γ, IL-4, IL-17, and mucin-2 in Cholestatic Rats.

Background and rationale for the study. Bacterial translocation is an important triggering factor of infection and mortality in cirrhosis. In a rat model using bile duct ligation (BDL), bacterial translocation appears within 24 h after ligation. The dynamic between TH1/TH2/TH17 cytokines and the integrity of the colonic mucosa in the context of cirrhosis is little known. This study aims to determine the link between bacterial translocation and intestinal inflammation in a cholestasis model. Additionally, alterations of the colonic mucus layer and the bacterial load were also addressed. RESULTS: Bacterial translocation detected by microbiological cultures and MALDI-TOF showed that Escherichia coli predominates in mesenteric lymph nodes of BDL rats. Intestinal bacterial load analyzed by qPCR indicates a dramatic Escherichia/Shigella overgrowth at 8 and 30 days post-BDL. IFN-γ, IL-4, and IL-17 evaluated by Western blotting were increased at 8 and 30 days in the small intestine. In the colon, in contrast, only IFN-γ was significantly increased. The colonic mucus layer and mucin-2 expression determined by Alcian blue staining and immunohistochemistry surprisingly showed an increase in the mucus layer thickness related to increased mucin-2 expression during the entire process of liver damage. Hepatic enzymes, as well as collagen I, collagen III, TNF-α, and IL-6 liver gene expression were increased. In conclusion, bacterial overgrowth associated with bacterial translocation is linked to the over-expression of IFN-γ, IL-4, IL-17 and mucin-2. These molecules might facilitate the intestinal permeability through exacerbating the inflammatory process and disturbing tight junctions, leading to the perpetuation of the liver damage.

Characterization of B7H6, an endogenous ligand for the NK cell activating receptor NKp30, reveals the identity of two different soluble isoforms during normal human pregnancy.

B7H6, an endogenous ligand expressed on tumor cell surfaces, triggers NKp30-mediated activation of human NK cells. In contrast, the release of soluble B7H6 has been proposed as a novel mechanism by which tumors might evade NK cell-mediated recognition. Since NK cells are critical for the maintenance of early pregnancy, it is not illogical that soluble B7H6 might also be an important factor in directing NK cell activity during normal pregnancy. Thus, this study was focused on the characterization of soluble B7H6 during the development of normal pregnancy. Serum samples were obtained from healthy pregnant women who were experiencing their second pregnancies (n=36). Additionally, 17 of these pregnant participants were longitudinally studied for the presence of B7H6 during their second and third trimesters. Age-matched healthy non-pregnant women served as controls (n=30). The presence of soluble B7H6 was revealed by Western blotting. A further characterization was performed using an immunoproteomic approach based on 2DE-Western blotting combined with MALDI-MS. The results show that sera from all pregnant women were characterized by the presence of two novel isoforms of B7H6, both with lower MW than the reported of 51kDa. These isoforms were either a heavy (∼37kDa) or a light isoform (∼30kDa) and were mutually exclusive. N-glycosylation did not completely explain the different molecular weights exhibited by the two isoforms, as was demonstrated by enzymatic deglycosylation with PNGase F. The confirmation of the identity and molecular mass of each isoform indicates that B7H6, while maintaining the C- and N-termini, is most likely released during pregnancy by a mechanism distinct from proteolytic cleavage. We found that both isoforms, but mainly the heavier B7H6, were released via exosomes; and that the lighter isoform was also released in an exosome-free manner that was not observed in the heavy isoform samples. In conclusion, we find that soluble B7H6 is constitutively expressed during pregnancy and that, moreover, the soluble B7H6 is present in two new isoforms, which are released by exosomal and exosome-free mechanisms.

Loss of CD28 within CD4+ T cell subsets from cervical cancer patients is accompanied by the acquisition of intracellular perforin, and is further enhanced by NKG2D expression.

CD28 is well characterized as an essential co-stimulatory receptor critical for activation, proliferation and survival processes in CD4+ T cells. Populations of CD4+CD28null T cells, with apparently contradictory physiological roles, have recently been reported, along with the co-expression of the NK activating receptor NKG2D, in autoimmune diseases and chronic viral inflammation. Paradoxically, studies in cancer suggest that an expanded CD4+NKG2D+ population may be armed with immunosuppressive properties. We have recently reported the existence of two separate CD4+NKG2D+ T cell populations, which were defined by the presence or absence of the co-stimulatory molecule CD28, with the CD4+CD28nullNKG2D+ population more frequently observed in women with cervical cancer. This has led to the present effort to further characterize this population and to determine if the loss of CD28 influences the acquisition of cytotoxic or regulatory markers. In the present work, a multicolor flow cytometry protocol was used to analyze the expression of cytotoxic and immunoregulatory markers on circulating CD4+ T cells characterized by the presence or absence of CD28 and NKG2D in patients with invasive cervical carcinoma and age/gender-matched healthy controls. A noticeable expansion of CD4+CD28null cells, many of them NKG2D+, were observed in selected cervical cancer samples. This CD4+CD28null T cell population was characterized by a lack of immunoregulatory markers, as well as very low basal levels of intracellular IFN-γ, TNF-α, TGF-ß, and IL-10. Intracellular perforin, however, was found to be significantly increased in this CD4+CD28null population, and increases in the mean fluorescence intensity of perforin were found to be enhanced by the presence of NKG2D. In conclusion, our data provide the first evidence of a strict link between the absence of CD28 and the expression of perforin, which is likewise enhanced by the expression of NKG2D, within selected CD4+ T cells from cervical cancer patients.

Expression of ADAM10, Fas, FasL and Soluble FasL in Patients with Oral Squamous Cell Carcinoma (OSCC) and their Association with Clinical-Pathological Parameters.

ADAM10 has been implicated in the progression of various solid tumors. ADAM10 regulates the cleavage of the FasL ectodomain from the plasma membrane of different cell types, generating the soluble FasL fragment (sFasL). Currently, there are few studies in oral squamous cell carcinoma (OSCC) that correlate levels of ADAM10 and FasL in the tumor microenvironment with clinical parameters of the disease. To determine the expression of ADAM10, Fas, FasL and sFasL in patients with OSCC and its association with TNM stage. Twenty-five patients with OSCC and 25 healthy controls were included. Biopsies of tumor tissue from patients with OSCC and buccal mucosa in controls were obtained. ADAM10, Fas, and FasL were analyzed by Western blotting. sFasL was quantified by ELISA. ADAM10 and Fas decreased significantly in OSCC compared with controls. Relatedly, within the OSCC group, Fas and ADAM10 decreased in accordance with tumor disease stage; in stages I/II, as well as in tumors of smaller diameter (T1-T2), ADAM10 showed higher levels when compared to patients with T3-T4 tumors and in stage III-IV. FasL in the tumor microenvironment and serum FasL showed no significant differences between both groups. Levels of complete FasL and cleaved FasL were positively correlated in controls; this correlation is preserved in patients with tumors in early stages (I-II), but is lost in later stage (III-IV). The dysregulation of ADAM10, Fas and FasL could be useful indicators of the progression and severity of OSCC.

Chronic exposure to endosulfan induces inflammation in murine colon via ß-catenin expression and IL-6 production.

Endosulfan (ENDO) is a widely used organochlorine (OC) pesticide and persistent organo-pollutant. Epidemiological studies have shown that high levels of OC exposure were related to colorectal cancer (CRC) incidence. The objectives of the present study were to evaluate histological changes in the colon, as well as in in situ expression of ß-catenin and P-selectin, and serum levels of select pro-inflammatory cytokines in mice administered ENDO; there is a relationship between increased serum IL-6 and P-selectin levels in CRC patients and aberrant ß-catenin signaling is important in initiation/maintenance of most CRCs. Mice were exposed to ENDO (at dose < LD50) orally once a week for up to 24 weeks, and monitored (inclusive) for a total of 42 weeks. The experiment was comprised of three groups, one that did not receive ENDO (olive oil vehicle), one administered 2 mg ENDO/kg/week and a positive control (for induction of CRC) given a weekly 20 mg 1,2-dimethylhydrazine (DMH)/kg injection. The results indicated that oral administration of ENDO provoked moderate inflammation starting at six weeks, and severe colonic inflammation with an appearance of dysplastic formations (aberrant crypts) in mice treated with ENDO (or DMH) for 12 weeks or longer. Serum IL-6 levels significantly increased starting at six weeks and rose to a peak of 15-fold higher than in controls at 42 weeks; TNFα levels likewise significantly increased, with a later peak (≈four-fold higher than controls) at 30-42 weeks. Immunohistochemical analysis of the colon also showed that expression of ß-catenin and P-selectin increased with length of exposure to ENDO. Taken together, the results indicate that continued repeated oral exposure to ENDO induces increased expression of ß-catenin and P-selectin, inflammation in the colon, and, ultimately, local tissue dysplasia.

An approach to the immunophenotypic features of circulating CD4⁺NKG2D⁺ T cells in invasive cervical carcinoma.

BACKGROUND: NKG2D, an activating immunoreceptor, is primarily restricted to NK cells and CD8(+) T cells. The existence of an atypical cytotoxic CD4(+)NKG2D(+) T cell population has also been found in patients with autoimmune dysfunctions. Nonetheless, contradictory evidence has categorized this population with a regulatory rather than cytotoxic role in other situations. These confounding data have led to the proposal that two distinct CD4(+)NKG2D(+) T cell subsets might exist. The immune response elicited in cervical cancer has been characterized by apparent contradictions concerning the role that T cells, in particular T-helper cells, might be playing in the control of the tumor growth. Interestingly, we recently reported a substantial increase in the frequency of CD4(+)NKG2D(+) T cells in patients with cervical intraepithelial neoplasia grade-1. However, whether this particular population is also found in patients with more advanced cervical lesions or whether they express a distinctive phenotype remains still to be clarified. In this urgent study, we focused our attention on the immunophenotypic characterization of CD4(+)NKG2D(+) T cells in patients with well-established cervical carcinoma and revealed the existence of at least two separate CD4(+)NKG2D(+) T cell subsets defined by the co-expression or absence of CD28. RESULTS: Patients with diagnosis of invasive cervical carcinoma were enrolled in the study. A group of healthy individuals was also included. Multicolor flow cytometry was used for exploration of TCR alpha/beta, CD28, CD158b, CD45RO, HLA-DR, CD161, and CD107a. A Luminex-based cytokine kit was used to quantify the levels of pro- and anti-inflammatory cytokines. We found an increased percentage of CD4(+)NKG2D(+) T cells in patients with cervical cancer when compared with controls. Accordingly with an increase of CD4(+)NKG2D(+) T cells, we found decreased CD28 expression. The activating or degranulation markers HLA-DR, CD161, and CD107a were heterogeneously expressed. The levels of IL-1beta, IL-2, TNF-alpha, and IL-10 were negatively correlated with the percentages of CD4(+)NKG2D(+) T cells in patients with cervical carcinoma. CONCLUSIONS: Taken together, our results reveal the existence of two separate CD4(+)NKG2D(+) T cell subsets defined by the co-expression or absence of CD28, the latter more likely to be present in patients with cervical cancer.

Substantial increase in the frequency of circulating CD4+NKG2D+ T cells in patients with cervical intraepithelial neoplasia grade 1.

BACKGROUND: The NKG2D receptor confers important activating signals to NK cells via ligands expressed during cellular stress and viral infection. This receptor has generated great interest because not only is it expressed on NK cells, but it is also seen in virtually all CD8+ cytotoxic T cells and is classically considered absent in CD4+ T cells. However, recent studies have identified a distinctive population of CD4+ T cells that do express NKG2D, which could represent a particular cytotoxic effector population involved in viral infections and chronic diseases. On the other hand, increased incidence of human papillomavirus-associated lesions in CD4+ T cell-immunocompromised individuals suggests that CD4+ T cells play a key role in controlling the viral infection. Therefore, this study was focused on identifying the frequency of NKG2D-expressing CD4+ T cells in patients with cervical intraepithelial neoplasia (CIN) 1. Additionally, factors influencing CD4+NKG2D+ T cell expansion were also measured. RESULTS: Close to 50% of patients with CIN 1 contained at least one of the 37 HPV types detected by our genotyping system. A tendency for increased CD4+ T cells and CD8+ T cells and decreased NK cells was found in CIN 1 patients. The percentage of circulating CD4+ T cells co-expressing the NKG2D receptor significantly increased in women with CIN 1 versus control group. Interestingly, the increase of CD4+NKG2D+ T cells was seen in patients with CIN 1, despite the overall levels of CD4+ T cells did not significantly increase. We also found a significant increase of soluble MICB in CIN 1 patients; however, no correlation with the presence of CD4+NKG2D+ T cells was seen. While TGF-beta was significantly decreased in the group of CIN 1 patients, both TNF-alpha and IL-15 showed a tendency to increase in this group. CONCLUSIONS: Taken together, our results suggest that the significant increase within the CD4+NKG2D+ T cell population in CIN 1 patients might be the result of a chronic exposure to viral and/or pro-inflammatory factors, and concomitantly might also influence the clearance of CIN 1-type lesion.

MHC class I-related chain A and B ligands are differentially expressed in human cervical cancer cell lines.

BACKGROUND: Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present, one of the best-characterized activating receptors is NKG2D, which promotes the NK-mediated lysis of target cells by binding to a family of cell surface ligands encoded by the MHC class I chain-related (MIC) genes, among others. The goal of this study was to describe the expression pattern of MICA and MICB at the molecular and cellular levels in human cervical cancer cell lines infected or not with human papillomavirus, as well as in a non-tumorigenic keratinocyte cell line. RESULTS: Here we show that MICA and MICB exhibit differential expression patterns among HPV-infected (SiHa and HeLa) and non-infected cell lines (C33-A, a tumor cell line, and HaCaT, an immortalized keratinocyte cell line). Cell surface expression of MICA was higher than cell surface expression of MICB in the HPV-positive cell lines; in contrast, HPV-negative cells expressed lower levels of MICA. Interestingly, the MICA levels observed in C33-A cells were overcome by significantly higher MICB expression. Also, all cell lines released higher amounts of soluble MICB than of soluble MICA into the cell culture supernatant, although this was most pronounced in C33-A cells. Additionally, Real-Time PCR analysis demonstrated that MICA was strongly upregulated after genotoxic stress. CONCLUSIONS: This study provides evidence that even when MICA and MICB share a high degree of homology at both genomic and protein levels, differential regulation of their expression and cell surface appearance might be occurring in cervical cancer-derived cells.