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Immune checkpoint inhibitors (ICIs) are a group of drugs employed in the treatment of various types of malignant tumors and improve the therapeutic effect. ICIs blocks negative co-stimulatory molecules, such as programmed cell death gene-1 (PD-1) and its ligand (PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), reactivating the recognition and killing effect of the immune system on tumors. However, the reactivation of the immune system can also lead to the death of normal organs, tissues, and cells, eventually leading to immune-related adverse events (IRAEs). IRAEs involve various organs and tissues and also cause thyroid dysfunction. This article reviews the epidemiology, clinical manifestations, possible pathogenesis, and management of ICIs-related thyroid dysfunction., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhan, Feng, Liu, Guo, Chen, Yao and Sun.)

Human lymphocyte antigen (HLA) class I molecules play a central role in cytotoxic T lymphocytes (CTL)-based antitumor immunity. However, the expression rate of HLA class I in cancer cells remains a topic of discussion. We compared HLA class I expression levels between cancer cells and surrounding non-tumorous hepatocytes in 20 early-stage hepatocellular carcinoma (HCC) patients by immunohistochemistry using EMR 8-5. The expression levels of HLA class I were classified as negative, incomplete positive or complete positive. Similarly, for various types of solid cancers, HLA class I expression was examined. For the HLA class I expression in cancer cells, among 20 HCC patients, 13 were complete positive, 3 were incomplete positive, and 4 were negative. In addition, 15 (75.0%) had higher expression levels of HLA class I in cancer cells compared with that in surrounding non-tumorous hepatocytes. An interferon-γ (IFN-γ) enzyme-linked immunospot (ELISPOT) assay indicated that cancer cells with positive expression of HLA class I had strong sensitivity to antigen-specific CTL. We suggested that HLA class I expression in cancer cells could be involved in the clinical prognosis of HCC patients. Similarly, 66.7%, 100.0%, 66.7% and 62.5% of patients with early-stage pancreatic, gallbladder, esophageal and breast cancers, respectively, had higher expression levels of HLA class I in cancer cells than in surrounding normal tissue cells. We suggest that in several early-stage solid cancers, including HCC, HLA class I expression levels in cancer cells are higher than that in surrounding normal tissue cells, which could result in the anti-tumor effect of CTL-based cancer immunotherapy., (© 2019 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

The development of human leukocyte antigen (HLA) donor-specific antibody/antibodies (DSA) is not well described in liver transplant (LT) patients undergoing immunosuppression (IS) withdrawal protocols despite the allograft risk associated with de novo DSA (dnDSA). We analyzed the development of dnDSA in 69 LT patients who received calcineurin inhibitor monotherapy and were enrolled in the ITN030ST study. Of these 69 patients, 40 stable patients were randomized to IS maintenance (n = 9) or IS minimization (n = 31). Nine of the 31 IS minimization patients achieved complete withdrawal and were free of IS. Among patients who achieved stable IS monotherapy 1 year after transplantation, the prevalence of dnDSA was 18.8%. Acute rejections and the biopsy-proven findings disqualifying patients from IS withdrawal attempt were factors associated with dnDSA development (P = 0.011 and P = 0.041, respectively). Among randomized patients, dnDSA prevalence was 51.7% after IS minimization and 66.7% in IS-free patients. dnDSA prevalence in patients on IS maintenance was 44.4%. dnDSA development during IS minimization was a risk factor for acute rejection (P = 0.015). The majority of dnDSA were against HLA-DQ antigens (78.7%). Conclusion. During the first year following transplantation, acute rejections increase the risk of developing dnDSA, so dnDSA positivity should be considered for IS withdrawal eligibility; during IS minimization, dnDSA development was associated with acute rejection, which prevented further IS withdrawal attempts., (© 2018 by the American Association for the Study of Liver Diseases.)

Lymphoid tissue organizer (LTo) cells, identified in mouse and human embryos, are thought to be precursors of stromal cells in secondary lymphoid organs. Whether LTo cells are present in human adults, however remains unknown. We obtained 15 stromal cell lines from tonsils from children who underwent tonsillectomy, and studied the antigen phenotype of these tonsil stromal cell (TSC) lines by flow cytometry and RT-PCR. Cell lines met the minimal criteria proposed by the International Society for Cellular Therapy to define human mesenchymal stem/stromal cells (MSCs): plastic-adherent capacity; expression of CD73, CD90 and CD105, lack of CD45, CD19 and HLA-DR; and capacity to differentiate into adipocytes, osteoblasts and chondrocytes. Furthermore, our TSC lines exhibited an antigen phenotype and functional characteristics very similar to those seen in murine embryo LTo cells: they expressed chemokines CCL19, CCL21 and CXCL13, cytokines TRANCE and IL-7, and adhesion molecules ICAM-1, mucosal addressin cell adhesion molecule (MadCAM)-1 and VCAM-1. The expression of LTo cell-associated markers and functions were upregulated by lymphotoxin (LT)α1β2 and TNF, two cytokines involved in the development and maturation of secondary lymphoid tissues. Our results show that TSCs are tonsil MSCs that differentiate into LTo-like cells in response to the effects of these cytokines., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aims: Adult T cell leukaemia/lymphoma (ATLL) is an aggressive malignancy with a poor prognosis. Human leucocyte antigen (HLA) and β2 microglobulin (β2M) serve as key molecules in tumour immunity, and their expression is reduced frequently in tumour cells. Programmed cell death (PD)-1/PD-ligand1 (PD-L1) interactions play a role in escape of tumour cells from T cell immunity. Therefore, this study aimed to determine the clinicopathological relevance of HLA and β2M expressions in ATLL cells and PD-L1 expression in lymphoma or stromal cells and predict the overall survival of patients with ATLL., Methods and Results: We analysed a total of 123 biopsy samples from patients newly diagnosed with ATLL by using immunohistochemical analysis. Of the patients enrolled, 91 (74%) were positive for HLA (in cell membrane, 60 patients), 89 (72%) were positive for β2M (in cell membrane, 54 patients) and 48 (39%) were positive for both HLA and β2M in the cell membrane (HLA m+ β2M m+ ). No significant clinical differences other than prognosis were found between the HLA m+ β2M m+ group and the other groups. Immunophenotypical evaluation revealed significantly higher rates of CD30-positive lymphoma cells (P = 0.003) and PD-L1-positive stromal cells in microenvironments (miPD-L1 high ) (P = 0.011) of the HLA m+ β2M m+ group than in the other groups. The HLA m+ β2M m+ group had a significantly better prognosis that the other groups (P = 0.0096), and patients showing HLA m+ β2M m+ with miPD-L1 high had the most favourable prognosis among all groups., Conclusions: The membranous expression of HLA and β2M is likely to reflect the immune response and would be useful to predict prognosis before starting ATLL therapy., (© 2018 John Wiley & Sons Ltd.)

The accurate typing of human leukocyte antigen (HLA) alleles is critical for a variety of medical applications, such as genomic studies of multifactorial diseases, including immune system and inflammation-related disorders, and donor selection in organ transplantation and regenerative medicine. Here, we developed a new algorithm for determining HLA alleles using next-generation sequencing (NGS) results. The method consists of constructing an extensive dictionary of HLA alleles, precise mapping of the NGS reads, and calculating a score based on weighted read counts to select the most suitable pair of alleles. The developed algorithm compares the score of all allele pairs, taking into account variation not only in the domain for antigen presentation (G-DOMAIN), but also outside this domain. Using this method, HLA alleles could be determined with 6-digit precision. We showed that our method was more accurate than other NGS-based methods and revealed limitations of the conventional HLA typing technologies. Furthermore, we determined the complete genomic sequence of an HLA-A-like-pseudogene when we assembled NGS reads that had caused arguable typing, and found its identity with HLA-Y*02:01. The accuracy of the HLA-A allele typing was improved after the HLA-Y*02:01 sequence was included in the HLA allele dictionary., (© 2017 The Authors. **Human Mutation published by Wiley Periodicals, Inc.)

Immune system dysfunction is a common condition in chronic kidney disease (CKD). The present study investigated the effect of p-Cresyl sulfate (pCS) on human cell line U937 monocyte-derived macrophages (MDM) activity. MDM (1×10 6 cells/mL) were incubated with pCS (10, 25, or 50μg/mL), with or without lipopolysaccharide (LPS; 25ng/mL) and then evaluated NO production, phagocytosis and antigen-presenting molecules expression (HLA-ABC, HLA-DR, CD80 and CD86). All analyses were performed by flow cytometry. All pCS concentrations were able to increase NO production (49±12.1%, 39.8±7.75%, 43.7±11.9%, respectively) compared to untreated cells (4.35±3.34%) after 6h incubation but only the lowest concentration increased this production after 12h (82.9±8.6%, 61±7.2%, 40.8±11.7%). Combined with LPS, the same results were observed. Regarding to phagocytosis, all concentrations were able to induce bead engulfment (35.4±2.71%, 30±3.04%, 23.28±4.58%). In addition, pCS (50μg/mL) was able to increase HLA-ABC and CD80 expression, showed a slight effect on HLA-DR expression and, no difference in basal CD86 levels. pCS can induce an increased oxidative burst and phagocytosis by human macrophages while no modulation of HLA-DR or CD86 expression was induced. Together, these results suggest that pCS induces macrophage activation but interfere in antigen processing, leading to a failure in adaptive immune response in CKD., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Idiopathic achalasia is characterized by the absence of peristalsis secondary to loss of neurons in the myenteric plexus that hampers proper relaxation of the lower esophageal sphincter. Achalasia can be considered a multifactorial disorder as it occurs in related individuals and is associated with HLA class II genes, thereby suggesting genetic influence. We used microarray technology and advanced in-silico functional analyses to perform the first genome-wide expression profiling of mRNA in tissue samples from 12 achalasia and 5 control patients. It revealed 1,728 differentially expressed genes, of these, 837 (48.4%) were up-regulated in cases. In particular, genes participating to the smooth muscle contraction biological function were mostly up-regulated. Functional analysis revealed a significant enrichment of neuronal/muscular and neuronal/immunity processes. Upstream regulatory analysis of 180 genes involved in these processes suggested TLR4 and IL18 as critical key-players. Two functional gene networks were significantly over-represented: one involved in organ morphology, skeletal muscle system development and function, and neurological diseases, and the other participating in cell morphology, humoral immune response and cellular movement. These results highlight on pivotal genes that may play critical roles in neuronal/muscular and neuronal/immunity processes, and that may contribute to the onset and development of achalasia.

Aim: To isolate and characterize limbal mesenchymal stem cells (LMSCs) from human corneoscleral rings., Materials & Methods: Cells were isolated from corneoscleral rings and cultured in a mesenchymal stem cell (MSC)-selective media and examined for differentiation, phenotyping and characterization., Results: LMSCs were capable of trilineage differentiation, adhered to tissue culture plastic, expressed HLA class I and cell surface antigens associated with human MSC while having no/low expression of HLA class II and negative hematopoietic lineage markers. They were capable for CXCL12-mediated cellular migration. LMSCs adhered, proliferated on amniotic membrane and expressed the common putative limbal stem cell markers., Conclusion: Limbal-derived MSC exhibited plasticity, could maintain limbal markers expression and demonstrated viable growth on amniotic membrane.

Human herpesvirus 6A (HHV-6A) causes ubiquitous infections and has been associated with several diseases in immunosuppressed and immune dysregulated individuals. Although considered a lymphotropic virus, HHV-6A has the potential to infect many cell types, inducing important alterations in the infected cell. In our search for additional potential targets for HHV-6A infection, we analyzed the susceptibility of human mesothelial cells to viral infection. HHV-6A infection was performed and analyzed on primary human mesothelial cells isolated from serous cavity fluid, infected in vitro with a cell-free HHV-6A inoculum. The results demonstrated that mesothelial cells are susceptible to in vitro HHV-6A infection, and more importantly, that the virus induces an alteration of HLA expression on the cell surface, inducing HLA class II and HLA-G de novo expression. Since mesothelial cells play a pivotal role in many processes, including inflammation and antigen presentation, we speculate that, in vivo, this virus-induced perturbation might be correlated to alterations in mesothelium functions.

The relationship between miscarriage and fertility is complex. While most healthcare settings treat miscarriage as a problem of subfertility in assisted reproduction units, others believe that miscarriage occurs in super-fertile women. Infertile women undergoing assisted reproduction are at a greater risk of having a miscarriage especially at an advanced age compared with women conceiving naturally. Aberrant expression of immunological factors and chromosomal abnormalities underlie both infertility and miscarriage. Common risk factors include increased maternal age, obesity, smoking, alcohol, pre-existing medical conditions and anatomical abnormalities of the reproductive system. Management pathways of both conditions may be similar with pre-implantation genetic testing and assisted reproductive technology used in both conditions. This paper discusses the synergies and differences between the two conditions in terms of their epidemiology, etiopathogenesis, risk factors and management strategies. The two conditions are related as degrees of severity of reproductive failure with common pathways in manifestation and management.

The high variability of the human leukocyte antigen (HLA) remains a major obstacle to the application of allogeneic products in cell-based therapies. We have developed a strategy to decrease the immunogenicity of cell and tissues to improve their survival after allogeneic transplantation in the absence of immunosuppression. Using RNA interference technology, the expression of HLA class I and II was stably downregulated. HLA-silenced cells demonstrated to prevent a de novo and escape a pre-formed alloimmune response in vitro and in vivo. Also, they demonstrated to be capable of engraft and survive after allogeneic transplantation independently of the donor's and recipient's genetic background. The generation of HLA-universal cells has may open new horizons in the field of regenerative medicine. Some of the potential clinical applications of HLA universal cells will be discussed in this review., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: Loss of expression of HLA class I is a mechanism of immune evasion in various cancers that is often associated with a worse patient outcome. We analyzed HLA expression in a large cohort with penile cancer in relation to clinical outcome., Materials and Methods: We used penile cancer tissue blocks from 168 patients who underwent surgical resection between 2000 and 2009 to construct tissue microarrays. Immunohistochemical staining was done with antibodies directed against classic and nonclassic HLA molecules. HLA expression was scored semiquantitatively, divided into 3 expression groups and correlated with clinicopathological variables, including HPV and survival. Survival analysis was performed using the Kaplan-Meier method and Cox proportional hazards models., Results: Complete and partial loss of total classic HLA class I was observed in 32% and 50% of cases, and up-regulation of HLA-E and G in 16% and 13%, respectively. When corrected for relevant clinical parameters, partial HLA-A loss was significantly associated with decreased survival overall (HR 2.3, 95% CI 1.1-4.6) and in HPV negative patients alone (HR 3.4, 95% CI 1.4-8.4). Abnormal HLA-B/C, E or G expression levels were not associated with survival., Conclusions: To our knowledge this is the first study to describe a link between HLA expression and the clinical outcome of penile cancer. HLA down-regulation occurs frequently and partial loss of HLA-A is an independent predictor of poor survival in HPV negative patients. Complete understanding of the mechanisms and relevance of HLA down-regulation and immune evasion in regard to the clinical outcome will contribute to the future design of immunotherapy interventions., (Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Pluripotent stem cells, including human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs), have been regarded as useful sources for cell-based transplantation therapy. However, immunogenicity of the cells remains the major determinant for successful clinical application. We report the examination of several hESC lines (NTU1 and H9), hiPSC lines, and their derivatives (including stem cell-derived hepatocytes) for the expression of major histocompatibility complex (MHC), natural killer (NK) cell receptor (NKp30, NKp44, NKp46) ligand, immune-related genes, human leukocyte antigen (HLA) haplotyping, and the effects in functional mixed lymphocyte reaction (MLR). Flow cytometry showed lower levels (percentages and fluorescence intensities) of MHC class I (MHC-I) molecules, β2-microglobulin, and HLA-E in undifferentiated stem cells. The levels were increased after cotreatment with interferon-γ and/or in vitro differentiation. Antigen-presenting cell markers (CD11c, CD80, and CD86) and MHC-II (HLA-DP, -DQ, and -DR) remained low throughout the treatments. Recognition of stem cells/derivatives by NK lysis receptors were lower or absent. Activation of responder lymphocytes was significantly lower by undifferentiated stem cells than by allogeneic lymphocytes in MLR, but differentiated NTU1 hESCs induced a cell number-dependent lymphocyte proliferation comparable with that by allogeneic lymphocytes. Interestingly, activation of lymphocytes by differentiated hiPSCs or H9 cells became blunted at higher cell numbers. Real-time reverse transcriptase PCR (RT-PCR) showed significant differential expression of immune privilege genes (TGF-β2, Arginase 2, Indole 1, GATA3, POMC, VIP, CALCA, CALCB, IL-1RN, CD95L, CR1L, Serpine 1, HMOX1, IL6, LGALS3, HEBP1, THBS1, CD59, and LGALS1) in pluripotent stem cells/derivatives when compared to somatic cells. It was concluded that pluripotent stem cells/derivatives are predicted to be immunogenic, though evidence suggests some level of potential immune privilege. In addition, differential immunogenicity may exist between different pluripotent stem cell lines and their derivatives.

HIV-1-infected subjects, despite control of viral replication with ART, have an altered immune cytokine/chemokine milieu. Changes in systemic cytokines and chemokines can alter immune responses. IP-10, in particular, has been associated with pathogenesis in a number of conditions, and we found that IP-10 is increased in serum in subjects who are HIV-1 infected and on stable ART compared with HIV-1-uninfected individuals. In a series of in vitro studies, we found that PBMCs exposed to IP-10 showed a significant decrease in the number of cells capable of secreting IFN-γ, as well as other cytokines, when stimulated with recall antigens. Furthermore, treatment with IP-10 led to decreased antigen-specific calcium signaling and MAPK38 phosphorylation. Importantly, the cytokines, as well as proliferative responses, could be enhanced with an IP-10 Nab. Our findings suggest that IP-10-modulating drugs may potentially enhance T cell responses to vaccination and HIV-1 in HIV+ subjects on ART., (© 2014 Society for Leukocyte Biology.)

Human skin-derived precursors (hSKPs) are multipotent somatic stem cells that persist within the dermis throughout adulthood and harbor potential clinical applicability. In this study, we investigated their immunogenicity and immunosuppressive features, both in vitro and in vivo. As such, this study provides a solid basis for developing their future clinical applications. We found that hSKPs express HLA-ABC molecules, but not HLA-DR, rendering them poorly immunogenic. Using a coculture set-up, we could further demonstrate that hSKPs inhibit the proliferation of allogeneic activated T cells and alter their cytokine secretion profile, in a dose-dependent manner. Cotransplantation of hSKP and human peripheral blood leukocytes (PBL) into severe combined immune-deficient mice also showed a significant impairment of the graft-versus-host response 1 week post-transplantation and a drastic increase in survival time of 60%. From a mechanistic point of view, we found that hSKPs require cell contact as well as secretion of soluble inhibitory factors in order to modulate the immune response. The expression/secretion levels of these factors further increases upon inflammation or in the presence of activated T cells. As such, we believe that these features could be beneficial in a later allogeneic clinical setting, because rejection of engrafted allogeneic hSKP might be delayed or even avoided due to their own promotion of a tolerogenic microenvironment., (© 2014 AlphaMed Press.)

Background: Endothelial colony-forming cells (ECFC) are endowed with vascular regenerative ability in vivo and in vitro. In this study we compared the genotypic profile and the immunogenic potential of adult and cord blood ECFC, in order to explore the feasibility of using them as a cell therapy product., Materials and Methods: ECFC were obtained from cord blood samples not suitable for haematopoietic stem cell transplantation and from adult healthy blood donors after informed consent. Genotypes were analysed by commercially available microarray assays and results were confirmed by real-time polymerase chain reaction analysis. HLA antigen expression was evaluated by flow-cytometry. Immunogenic capacity was investigated by evaluating the activation of allogeneic lymphocytes and monocytes in co-cultures with ECFC., Results: Microarray assays revealed that the genetic profile of cord blood and adult ECFC differed in about 20% of examined genes. We found that cord blood ECFC were characterised by lower pro-inflammatory and pro-thrombotic gene expression as compared to adult ECFC. Furthermore, whereas cord blood and adult ECFCs expressed similar amount of HLA molecules both at baseline and after incubation with γ-interferon, cord blood ECFC elicited a weaker expression of pro-inflammatory cytokine genes. Finally, we observed no differences in the amount of HLA antigens expressed among cord blood ECFC, adult ECFC and mesenchymal cells., Conclusions: Our observations suggest that cord blood ECFC have a lower pro-inflammatory and pro-thrombotic profile than adult ECFC. These preliminary data offer level-headed evidence to use cord blood ECFC as a cell therapy product in vascular diseases.

Background: Melanoma-associated antigen-A4 (MAGE-A4) is one of the candidates for a target of immunotherapy and is expressed in non-small cell lung cancer (NSCLC). However, tumors sometimes lose human leukocyte antigen (HLA) class I expression, and tumor-specific T cells cannot eliminate the tumor with loss of HLA. However, the relationship between MAGE-A4 expression and HLA loss has remained unclear., Methods: Among 363 NSCLC patients who consecutively underwent curative surgery, 187 cases whose material could be analyzed were reviewed. The expression of HLA class I molecules was assessed by immunohistochemical staining. The expression of MAGE-A4 was analyzed by RT-PCR., Results: Seventy-seven tumors expressed HLA normally; however, 110 tumors lost HLA. The proportion of patients with a smoking habit and expressing the MAGE-A4 gene in patients with HLA loss was higher than those with HLA expression (p = 0.04 and 0.028, respectively). Five-year overall survival (OS) rate in the patients expressing MAGE-A4 but with loss of HLA was 52.4 %, and OS was significantly poorer than their counterparts (74.0 %, p = 0.036). Multivariate analysis indicated that advanced stage or history of smoking and HLA loss was an independently poor prognostic predictor of OS in NSCLC (p < 0.01 and p = 0.04, respectively)., Conclusion: HLA class I loss in NSCLC was related to smoking history and MAGE-A4 expression of tumors. HLA class I loss in smokers or patients with the MAGE-A4 gene was a prognostic factors in NSCLC.

The contribution of host T-cell immunity and HLA class I alleles to the control of human immunodeficiency virus (HIV-1) replication in natural infection is widely recognized. We assessed whether vaccine-induced T-cell immunity, or expression of certain HLA alleles, impacted HIV-1 control after infection in the Step MRKAd5/HIV-1 gag/pol/nef study. Vaccine-induced T cells were associated with reduced plasma viremia, with subjects targeting ≥3 gag peptides presenting with half-log lower mean viral loads than subjects without Gag responses. This effect was stronger in participants infected proximal to vaccination and was independent of our observed association of HLA-B*27, -B*57 and -B*58:01 alleles with lower HIV-1 viremia. These findings support the ability of vaccine-induced T-cell responses to influence postinfection outcome and provide a rationale for the generation of T-cell responses by vaccination to reduce viremia if protection from acquisition is not achieved. Clinical trials identifier: NCT00095576.

Background: Microglia are the primary immune cells of the brain whose phenotype largely depends on their surrounding micro-environment. Microglia respond to a multitude of soluble molecules produced by a variety of brain cells. Macrophage colony-stimulating factor (M-CSF) is a cytokine found in the brain whose receptor is expressed by microglia. Previous studies suggest a critical role for M-CSF in brain development and normal functioning as well as in several disease processes involving neuroinflammation., Methods: Using biopsy tissue from patients with intractable temporal epilepsy and autopsy tissue, we cultured primary adult human microglia to investigate their response to M-CSF. Mixed glial cultures were treated with 25 ng/ml M-CSF for 96 hours. Proliferation and phagocytosis assays, and high through-put immunocytochemistry, microscopy and image analysis were performed to investigate microglial phenotype and function., Results: We found that the phenotype of primary adult human microglia was markedly changed following exposure to M-CSF. A greater number of microglia were present in the M-CSF- treated cultures as the percentage of proliferating (BrdU and Ki67-positive) microglia was greatly increased. A number of changes in protein expression occurred following M-CSF treatment, including increased transcription factors PU.1 and C/EBPβ, increased DAP12 adaptor protein, increased M-CSF receptor (CSF-1R) and IGF-1 receptor, and reduced HLA-DP, DQ, DR antigen presentation protein. Furthermore, a distinct morphological change was observed with elongation of microglial processes. These changes in phenotype were accompanied by a functional increase in phagocytosis of Aβ1-42 peptide., Conclusions: We show here that the cytokine M-CSF dramatically influences the phenotype of adult human microglia. These results pave the way for future investigation of M-CSF-related targets for human therapeutic benefit.

Type 1 diabetes (T1D) is an autoimmune disease characterized by known genetic risk factors with T cell-mediated infiltration and destruction of the beta cells within pancreatic islets. Autoantibodies are the most significant preclinical marker of T1D, and birth cohort studies have provided important insights into the natural history of autoimmunity and T1D. While HLA remains the strongest genetic risk factor, a number of novel gene variants associated with T1D have been found through genome-wide studies, some of which have been linked to suspected environmental risk factors. Multiple environmental factors that have been suggested to play a role in the development of T1D await confirmation. Current risk-stratification models for T1D take into account genetic risk factors and autoantibodies. In the future, metabolic profiles, epigenetics, as well as environmental risk factors may be included in such models., (© 2013 New York Academy of Sciences.)

Streptococcus pyogenes causes severe, invasive infections such as the sequelae associated with acute rheumatic fever, rheumatic heart disease, acute glomerulonephritis, uncomplicated pharyngitis, and pyoderma. Efforts to produce a vaccine against S. pyogenes began several decades ago, and different models have been proposed. We have developed a vaccine candidate peptide, StreptInCor, comprising 55 amino acid residues of the C-terminal portion of the M protein and encompassing both the T- and B-cell protective epitopes. The present article summarizes data from the previous 5 years during which we tested the immunogenicity and safety of StreptInCor in different animal models. We showed that StreptInCor overlapping peptides induced cellular and humoral immune responses of individuals bearing different HLA class II molecules. These results are consistent with peptides that have a universal vaccine epitope. The tridimensional molecular structure of StreptInCor was elucidated by nuclear magnetic resonance spectroscopy, which showed that its structure is composed of two microdomains linked by an 18-residue α-helix. Additionally, we comprehensively evaluated the structural stability of the StreptInCor peptide in different physicochemical conditions using circular dichroism. Additional experiments were performed with inbred, outbred, and HLA class II transgenic mice. Analysis of several organs of these mice showed neither deleterious nor autoimmune reactions even after a long period of vaccination, indicating that the StreptInCor candidate peptide could be considered as an immunogenic and safe vaccine.

Recent advances enabling efficient delivery of transgenes to human T cells have created opportunities to address obstacles that previously hindered the application of T cell therapy to cancer. Modification of T cells with transgenes encoding TCRs or chimeric antigen receptors allows tumor specificity to be conferred on functionally distinct T cell subsets, and incorporation of costimulatory molecules or cytokines can enable engineered T cells to bypass local and systemic tolerance mechanisms. Clinical studies of genetically modified T cell therapy for cancer have shown notable success; however, these trials demonstrate that tumor therapy with engineered high avidity tumor-reactive T cells may be accompanied by significant on-target toxicity, necessitating careful selection of target antigens and development of strategies to eliminate transferred cells., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Stat3 mediates a complex spectrum of cellular responses, including inflammation, cell proliferation, and apoptosis. Although evidence exists in support of a positive role for Stat3 in cancer, its role has remained somewhat controversial because of insufficient study of how its genetic deletion may affect carcinogenesis in various tissues. In this study, we show using epithelium-specific knockout mice (Stat3(Δ/Δ)) that Stat3 blunts rather than supports antitumor immunity in carcinogen-induced lung tumorigenesis. Although Stat3(Δ/Δ) mice did not show any lung defects in terms of proliferation, apoptosis, or angiogenesis, they exhibited reduced urethane-induced tumorigenesis and increased antitumor inflammation and natural killer (NK) cell immunity. Comparative microarray analysis revealed an increase in Stat3(Δ/Δ) tumors in proinflammatory chemokine production and a decrease in MHC class I antigen expression associated with NK cell recognition. Consistent with these findings, human non-small cell lung cancer (NSCLC) cells in which Stat3 was silenced displayed an enhancement of proinflammatory chemokine production, reduced expression of MHC class I antigen, and increased susceptibility to NK cell-mediated cytotoxicity. In addition, supernatants from Stat3-silenced NSCLC cells promoted monocyte migration. Collectively, our findings argue that Stat3 exerts an inhibitory effect on antitumor NK cell immunity in the setting of carcinogen-induced tumorigenesis.

NK cells control tumor and virus-infected cells through releasing cytotoxic granules and proinflammatory cytokines. IFN-γ and TNF-α secretions and cytotoxicity are regarded as two distinct functions of NK cells with little synergy in between as results of early association of the two functions with distinct subsets of NK populations and of the studies showing target cells developing NK resistance upon IFN-γ treatment. Here, we show that IFN-γ and TNF-α synergistically enhance NK cell cytotoxicity through NF-κB-dependent up-regulation of ICAM-1 expression in target cells, thereby promoting their conjugate formation with NK cells. Neutralizing IFN-γ and TNF-α during cytolysis significantly impaired NK cell lysis of the target cells. Further, tumor cells exhibiting IFN-γ-inducible lysis are generally less-sensitive NK target cells but express inducible levels of ICAM-1. In contrast, sensitive NK targets tend to express higher but less-inducible ICAM-1. Their preferential induction in the lysis of insensitive NK target cells suggests that IFN-γ and TNF-α are functionally linked to and should be regarded as an integral part of NK cytolytic function.

The roles of fibroblast growth factor-2 (FGF-2) in the hepatocellular carcinoma (HCC) development are still controversial. In this study, we investigated the expression of FGF-2 in chronic hepatitis (CH) type C patients with or without HCC and the immunoregulation of FGF-2 in NK sensitivity of HCC cells. The FGF-2 expressions were detected in the liver tissues of patients, but not in normal liver. The serum FGF-2 levels of the patients with CH, liver cirrhosis (LC) or HCC were significantly higher than those of healthy volunteers. The serum FGF-2 levels of patients decreased with the progression of chronic liver disease. HCC occurrence of LC patients with high levels of serum FGF-2 was significantly lower than that with low levels of serum FGF-2. Proinflammatory cytokines, such as IL-1β and IL-6, induced FGF-2 expressions in HCC cells and normal hepatocytes. FGF-2 stimulation resulted in increasing the expression of the membrane-bound major histocompatibility complex class I-related chain A (MICA), an NK activating molecule, and decreasing that of human leukocyte antigen (HLA) class I, an NK inhibitory molecule, on HCC cells. This did not occur with normal hepatocytes. Adding anti-FGF receptor-2 neutralizing antibody resulted in inhibiting the change of MICA and HLA class I expressions on FGF-2 stimulated HCC cells. FGF-2 stimulation on HCC cells resulted in increasing NK sensitivity against HCC cells. These findings indicate that FGF-2 produced by HCC cells or normal hepatocytes of chronic liver disease may play critical roles in eliminating HCC cells by innate immunity., (Copyright © 2011 UICC.)

Objective: Ovarian cancer is the leading cause of death from gynecologic cancers in the United States. Epothilone B (EpoB), Taxol and vinblastine are anti-neoplastic agents that interfere with microtubules and arrest the cell cycle in the G2/M phase. EpoB is being evaluated in phase III clinical trials, and its analogs are currently being used in the treatment of taxane-resistant metastatic breast cancer. Little is known about the effect of these drugs on the immune response to tumors. Cancer cells evade immune recognition by down-regulating HLA Class I expression, allowing escape from immune surveillance and destruction. Our data illustrates the effect of microtubule-interacting agents on HLA Class I and HLA-A2 expression as well as the modulation of cytokine expression in ovarian cancer cells., Methods: Ovarian cancer cells were treated with different concentrations of drugs. Cell surface expression and mRNA transcription of HLA Class I molecules and HLA-A2 was examined. IFNα, IL1β, IL12 and IL6 mRNA expression was also evaluated upon EpoB treatment., Results: Low-dose EpoB, Taxol and vinblastine greatly increased expression of HLA Class I and HLA-A2 molecules in Hey ovarian cancer cells. EpoB does not modulate HLA expression in drug-resistant ovarian cancer cells. The expression of IFNα, IL1β, IL12 and IL6 is also markedly increased upon EpoB treatment., Conclusions: Nanomolar concentrations of microtubule-interacting agents enhance immune-visibility of ovarian cancer cells by increasing HLA Class I and pro-inflammatory cytokine expression. Immune recognition of tumor cells may be improved., (Published by Elsevier Inc.)

Objective: An increase in the expression of autoantigens and their presenting molecules human leukocyte antigen (HLA) class I has been demonstrated to be responsible for autoimmune diseases. Thyroid transcription factor-1 (TTF-1 or NKX2-1) synchronously upregulates both HLA class I and thyroid-specific autoantigen, which may be involved in the pathological process of autoimmune thyroiditis. In this study, the expressions and potential role of TTF-1 and HLA class I in Hashimoto's disease (HT) were examined., Patients: In this study, 22 resection specimens clinically and histopathologically confirmed to have Hashimoto's disease and 30 normal thyroid specimens from adjacent tissues of thyroid adenoma were used., Measurement: Western blot, real-time PCR, and immunohistochemistry were performed to assay TTF-1 and HLA class I in the thyrocytes of Hashimoto's disease as well as in the normal thyroid from adjacent tissues of thyroid adenoma., Results: The TTF-1 and HLA class I in Hashimoto's disease were significantly higher than those in the controls., Conclusion: Upregulation of TTF-1 and HLA class I in Hashimoto's disease provide a clinical evidence for possible triggering of autoimmune reaction.

Identification of immune modifiers of inherited cancer syndromes may provide a rationale for preventive therapy. Cowden disease (CD) is a genetically heterogeneous inherited cancer syndrome that arises predominantly from germline phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mutation and increased phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR) signalling. However, many patients with classic CD diagnostic features are mutation-negative for PTEN (PTEN M-Neg). Interferon (IFN)-γ can modulate the PI3K/mTOR pathway, but its association with PTEN M-Neg CD remains unclear. This study assessed IFN-γ secretion by multi-colour flow cytometry in a CD kindred that was mutation-negative for PTEN and other known susceptibility genes. Because IFN-γ responses may be regulated by killer cell immunoglobulin-like receptors (KIR) and respective human leucocyte antigen (HLA) ligands, KIR/HLA genotypes were also assessed. Activating treatments induced greater IFN-γ secretion in PTEN M-Neg CD peripheral blood lymphocytes versus healthy controls. Increased frequency of activating KIR genes, potentially activating KIR/HLA compound genotypes and reduced frequency of inhibitory genotypes, were found in the PTEN M-Neg CD kindred. Differences of IFN-γ secretion were observed among PTEN M-Neg CD patients with distinct KIR/HLA compound genotypes. Taken together, these findings show enhanced lymphocyte secretion of IFN-γ that may influence the PI3K/mTOR CD causal molecular pathway in a PTEN mutation-negative CD kindred., (© 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.)

Background Aims: The beneficial activity of mesenchymal stromal cells (MSC) in allogeneic hematopietic stem cell transplantation requires correct use in terms of cell dose and timing of infusion and the identification of biomarkers for selection. The immunosuppressive bone marrow (BM)-derived MSC (BM-MSC) functions have been associated with the production of soluble HLA-G molecules (sHLA-G) via interleukin (IL)-10. We have established a reliable method for evaluating BM-MSC HLA-G expression without the influence of peripheral blood mononuclear cells (PBMC)., Methods: Thirteen BM-MSC from donors were activated with recombinant IL-10 or co-cultured with 10 different phytohemagglutinin (PHA)-treated PBMC (PHA-PBMC). Membrane-bound and sHLA-G expression was evaluated by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively; lymphoproliferation was measured by (methyl-(3)H)thymidine., Results: The results demonstrated the ability of IL-10 to stimulate both membrane-bound and sHLA-G production by BM-MSC. The levels of HLA-G expression induced by IL-10 in BM-MSC were associated with the inhibition of PHA-PBMC proliferation (sHLA-G, P = 0.0008, r = 0.9308; membrane HLA-G, P = 0.0005, r = 0.9502)., Conclusions: We propose the evaluation of sHLA-G production in IL-10-treated BM-MSC cultures as a possible marker of immunoregulatory function.

The role of nonclassical human leukocyte antigens G and E (HLA-G and HLA-E) was originally thought to be restricted to the protection of the fetus from a maternal allorecognition. Now it is known that HLA-G and HLA-E exert multiple immunoregulatory functions. A prognostic significance of the expression of HLA-G and HLA-E by neoplastic cells in glioblastoma is not well characterized. In this study, we evaluated the expression of HLA-G and HLA-E by neoplastic cells in 39 cases of glioblastoma. We found the production of HLA-G and HLA in a majority of cases. There was an unexpected positive correlation between the expression of HLA-E and length of survival. We speculate that the expression of this molecule by neoplastic cells may represent a coincidental selective pro-host advantage related to better response to subsequent therapeutic modalities. Mechanisms of glioblastoma cell pathophysiology and mechanisms of responses to therapeutic interventions in respect to the expression of these molecules deserves further study., (© 2010 Japanese Society of Neuropathology.)

Human leukocyte antigen G (HLA-G) is an immunotolerant nonclassical major histocompatibility complex Class Ib molecule. It is expressed by trophoblastic placental cells during pregnancy to protect the fetus from maternal alloreactivity. HLA-G is overexpressed in tumors and involved in cancer immune evasion. Reverse transcription-polymerase chain reaction and immunohistochemistry (IHC) were used to examine HLA-G expression in normal mammary and breast cancer cell lines and normal and human breast cancer tissues. Reverse transcription-polymerase chain reaction confirmed that normal epithelial MCF-12A cells had no HLA-G mRNA expression, whereas cancer cell lines MCF-7, T47D, and MDA-MB-231 and NCI/Adr-Res had various levels of HLA-G mRNA expression. Twelve (12) normal and 38 breast cancer tissues were examined by IHC. Fifty-eight (58) percent (22/38) of cancers had medium to strong staining to HLA-G, whereas only 8% (1/12) of normal breast tissues had medium to strong staining, and the difference was significant (p < 0.05). HLA-G staining was found in the membranes and cytoplasm of cancer cells. In conclusion, breast cancer cells overexpress HLA-G mRNA and protein, and this probably contributes to immune evasion.

Human leukocyte antigen-G (HLA-G) is a non-classical HLA-class Ib molecule with multiple immunoregulatory properties. Its main functions in physiological conditions are to abolish maternal immune cell activity against fetus and to establish immune tolerance at the maternal-fetal interface. In oncology, HLA-G molecules are aberrantly expressed in a variety of human neoplastic diseases and play an important role in the escape of tumor cells from immune surveillance. In the past few years, making use of HLA-G protein expression in tissues and circulating levels in body fluids as a tumor marker have been the focus of extensive research in the diagnosis and prognosis of several human malignancies. In addition, this molecule might be a promising target for future immune therapeutic approaches based on its immune tolerant functions and its highly specific expression for malignant transformation. In this review, we will summarize available literature data as well as our own works on HLA-G in cancer, and address some of the issues concerning its application in human neoplasia.

Human leukocyte Ag-G, a tolerogenic molecule that acts on cells of both innate and adaptive immunity, plays an important role in tumor progression, transplantation, placentation, as well as the protection of the allogeneic fetus from the maternal immune system. We investigated HLA-G mRNA and protein expression in human embryonic stem cells (hESC) derived from the inner cell mass (ICM) of blastocysts. hESC self-renew indefinitely in culture while maintaining pluripotency, providing an unlimited source of cells for therapy. HLA-G mRNA was present in early and late passage hESC, as assessed by real time RT-PCR. Protein expression was demonstrated by flow cytometry, immunocytochemistry, and ELISA on an hESC extract. Binding of HLA-G with its ILT2 receptor demonstrated the functional active status. To verify this finding in a physiologically relevant setting, HLA-G protein expression was investigated during preimplantation development. We demonstrated HLA-G protein expression in oocytes, cleavage stage embryos, and blastocysts, where we find it in trophectoderms but also in ICM cells. During blastocyst development, a downregulation of HLA-G in the ICM cells was present. This data might be important for cell therapy and transplantation because undifferentiated hESC can contaminate the transplant of differentiated stem cells and develop into malignant cancer cells.

As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)-G is well described as a tolerogenic molecule, we evaluated HLA-G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA-G expression was assessed by immunohistochemistry. No HLA-G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane-bound HLA-G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA-G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA-G expression presented a higher median HBV DNA viral load (10⁵ copies/mL) than those who did not express HLA-G (10(3.7) copies/mL). These results indicate that HLA-G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection., (© 2010 Blackwell Publishing Ltd.)

Objectives: To analyze the distribution of HLA alleles and HLA microsatellite alleles in Croatian patients with testicular carcinoma, compare it with that of healthy controls and investigate whether the polymorphism within the HLA region could be associated with the development of testicular cancer., Methods: Genomic DNA was isolated from the peripheral blood of 24 patients with testicular germ cell tumors (TGCT). Patients and controls were typed for HLA class I and class II polymorphism by the PCR-SSO method. Nine HLA microsatellites were analyzed by PCR and electrophoresis in an automated sequencer., Results: No significant deviation in the distribution of frequencies at HLA class I alleles was observed between patients and controls. Among HLA class II alleles, a statistically significant increase in the frequency of the HLA-DPB1*1701 allele was found among patients. The frequency of the HLA-DRB1*07-DQA1*0201-DQB1*0202 haplotype was increased in patients in comparison to the controls. Analysis of HLA microsatellites showed an increased frequency of D6S291-3 allele (p(corr) = 0.0455, OR = 3.05) among patients., Conclusions: The observed association of the disease and the DPB1*1701 allele as well as with the D6S291-3 allele suggests that this part of the HLA region might be involved in the pathogenesis of TGCT. Our data provide a basis for further studies about the correlation between the HLA region and testicular cancer., (Copyright © 2011 S. Karger AG, Basel.)

Aqueous humor (AqH) has been shown to have significant immunosuppressive effects on APCs in animal models. We wanted to establish whether, in humans, AqH can regulate dendritic cell (DC) function and to identify the dominant mechanism involved. Human AqH inhibited the capacity of human peripheral blood monocyte-derived DC to induce naive CD4(+) T cell proliferation and cytokine production in vitro, associated with a reduction in DC expression of the costimulatory molecule CD86. This was seen both for DC cultured under noninflammatory conditions (immature DC) and for DC stimulated by proinflammatory cytokines (mature DC). DC expression of MHC classes I/II and CD83 was reduced (mature DC only). Myeloid DC from peripheral blood were similarly sensitive to the effects of human AqH, but only under inflammatory conditions. The addition of α-melanocyte stimulating hormone and vasoactive intestinal peptide did not cause significant inhibition at physiological levels. However, the addition of exogenous cortisol at physiological levels recapitulated the AqH-induced reduction in CD86 and inhibition of DC-induced T cell proliferation, and blockade of cortisol in AqH partially reversed its suppressive effects. TGF-β2 had an additional effect with cortisol, and although simultaneous blockade of cortisol and TGF-β2 in AqH reduced its effectiveness, there was still a cortisol- and TGF-β-independent component. In humans, AqH regulates DC maturation and function by the combined actions of cortisol and TGF-β2, a pathway that is likely to contribute to the maintenance of immune privilege in the eye.

Nonclassical HLAs, HLA-E and HLA-G, are known to affect clinical outcome in various tumor types. We examined the clinical impact of HLA-E and HLA-G expression in early breast cancer patients, and related the results to tumor expression of classical HLA class I. Our study population (n = 677) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1995. Tissue microarray sections of arrayed tumor and normal control material were immunohistochemically stained for HLA-E and HLA-G. For evaluation of HLA-E and HLA-G and the combined variable, HLA-EG, a binary score was used. Expression of classical HLA class I molecules was determined previously. HLA-E, HLA-G, and HLA-EG on breast tumors were classified as expression in 50, 60, and 23% of patients, respectively. Remarkably, only in patients with loss of classical HLA class I tumor expression, expression of HLA-E (p = 0.027), HLA-G (p = 0.035), or HLA-EG (p = 0.001) resulted in a worse relapse-free period. An interaction was found between classical and nonclassical HLA class I expression (p = 0.002), suggestive for a biological connection. We have demonstrated that, next to expression of classical HLA class I, expression of HLA-E and HLA-G is an important factor in the prediction of outcome of breast cancer patients. These results provide further evidence that breast cancer is immunogenic, but also capable of evading tumor eradication by the host's immune system, by up- or downregulation of HLA class Ia and class Ib loci.

Soluble human leukocyte antigen-G (HLA-G) is involved in maternal-fetal tolerance, transplant acceptance, and tumor escape from immunosurveillance, operating by inhibiting activity of T, antigen presenting cells (APC), and natural killer (NK) cells. HLA-G gene expression is modulated in vitro after hypoxic conditions, a situation evidenced during pregnancy and tumor progression. In extreme altitude, mountaineers are in hypoxic conditions that generate physiologic adaptative responses, some of them giving rise to pathologic signs. We performed measurements of plasma soluble HLA-G in six climbers before departure of the expedition and during their ascent to and descent from summit of Mount Everest, and in 3 Sherpas at 5300-6400 m. We found that HLA-G levels are upregulated during the ascent with a unique pattern in comparison with angiogenic/lymphangiogenic factors. Our data suggest that HLA-G has to be taken into account in the mechanisms participating in adaptation to high altitudes and reinforce hypoxia as an important factor in the regulation of HLA-G expression., (Copyright © 2010 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

An attractive treatment of cancer consists in inducing tumor-eradicating CD8(+) CTL specific for tumor-associated Ags, such as NY-ESO-1 (ESO), a strongly immunogenic cancer germ line gene-encoded tumor-associated Ag, widely expressed on diverse tumors. To establish optimal priming of ESO-specific CTL and to define critical vaccine variables and mechanisms, we used HLA-A2/DR1 H-2(-/-) transgenic mice and sequential immunization with immunodominant DR1- and A2-restricted ESO peptides. Immunization of mice first with the DR1-restricted ESO(123-137) peptide and subsequently with mature dendritic cells (DCs) presenting this and the A2-restriced ESO(157-165) epitope generated abundant, circulating, high-avidity primary and memory CD8(+) T cells that efficiently killed A2/ESO(157-165)(+) tumor cells. This prime boost regimen was superior to other vaccine regimes and required strong Th1 cell responses, copresentation of MHC class I and MHC class II peptides by the same DC, and resulted in upregulation of sphingosine 1-phosphate receptor 1, and thus egress of freshly primed CD8(+) T cells from the draining lymph nodes into circulation. This well-defined system allowed detailed mechanistic analysis, which revealed that 1) the Th1 cytokines IFN-gamma and IL-2 played key roles in CTL priming, namely by upregulating on naive CD8(+) T cells the chemokine receptor CCR5; 2) the inflammatory chemokines CCL4 (MIP-1beta) and CCL3 (MIP-1alpha) chemoattracted primed CD4(+) T cells to mature DCs and activated, naive CD8(+) T cells to DC-CD4 conjugates, respectively; and 3) blockade of these chemokines or their common receptor CCR5 ablated priming of CD8(+) T cells and upregulation of sphingosine 1-phosphate receptor 1. These findings provide new opportunities for improving T cell cancer vaccines.

It is well known that the reproductive steroid hormones, particularly progesterone, in addition to its widely recognized effects on endometrial epithelial and stromal cells and spiral arteries, affect the activities of T cells and natural killer cells in the deciduas, thus inducing active immune tolerance against the fetal antigens. The immunomodulatory effects of progesterone on T cells, B cells and natural killer cells have been discussed extensively in the literature. The aim of the present review is to sum up and discuss the results from this and other laboratories of investigations on the effects of progesterone on dendritic cells and adult stem cells, which are some of the other cell populations present at the fetal-maternal interface and possibly are related to the immunoregulation during pregnancy. These cells have been shown to have a number of specific functions but their involvement in the entire process of regulation of the immune response in pregnancy is still under discussion. The present review focuses on facts showing that the progesterone is a kind of 'regulator of regulators' in the decidua, thus creating the most favourable conditions for the development of the semi-allogeneic fetus in successful pregnancy., (Copyright © 2010 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.)

The clinical relevance of human leucocyte antigen-G (HLA-G) has been postulated in malignancies. Hepatocellular carcinoma (HCC) is a major contributor to cancer incidence and mortality worldwide; however, potential roles of HLA-G in HCC remain unknown. In the current study, HLA-G expression in 219 primary HCC lesions and their adjacent non-tumourous samples was analysed with immunohistochemistry. Correlations among HLA-G expression and various clinical parameters were evaluated. Meanwhile, functional analysis of transfected cell surface HLA-G expression on NK cell cytolysis was performed in vitro. HLA-G expression was observed in 50.2% (110/219) of primary HCC lesions, and undetectable in corresponding adjacent normal liver tissues. HLA-G expression was found in 37.8%, 41.9% and 71.4% of stage I, II and III HCC lesions, respectively. Data revealed that HLA-G expression in HCC was strongly correlated to advanced disease stage (I versus II, P= 0.882; I versus III, P= 0.020; II versus III, P= 0.037). HLA-G expression was also more frequently observed in elder patients (≥median 52 years, 57.5%versus 43.4%, P= 0.004). Meanwhile, plasma soluble HLA-G in HCC patients was significantly higher than that in normal controls (median, 92.49U/ml versus 9.29U/ml, P= 0.000). Functional assay showed that HLA-G expression in transfected cells could dramatically decrease the NK cell cytolysis (P= 0.036), which could be markedly restored by the blockade of HLA-G (P= 0.004) and its receptor ILT2 (P= 0.019). Our finding indicated that HLA-G expression was strongly correlated to advanced disease stage, and more frequently observed in elder patients. Its relevance to HCC progression might be result from the inhibition of NK cell cytolysis., (© 2009 The Authors Journal compilation © 2010 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.)

Human leukocyte antigen-G (HLA-G) is a non-classical major histocompatibility complex class Ib molecule that acts as a specific immunosuppressor. Some studies have demonstrated that human papillomavirus (HPV) seems to be involved in lower or absent HLA-G expression, particularly in cervical cancer. In this study, we performed a cross-sectional study, systematically comparing the qualitative expression of the HLA-G5 isoform in invasive cervical carcinoma (ICC), stratifying patients according to the presence [ICC with metastasis (ICC(W))] and absence [ICC without metastasis (ICC(WT))] of metastasis, correlating these findings with interference of HPV and demographic and clinical variables. Seventy-nine patients with a diagnosis of ICC were stratified into two groups: ICC(WT) (n=52 patients) and ICC(W) (n=27). Two biopsies were collected from each patient (one from the tumor lesion and one from a lymph node). Immunohistochemistry analyses were performed for the HLA-G5 isoform, for HPV detection, and virus typing. HLA-G5 isoform molecules were detected in 25 cases (31.6%), 17 (32.7%) without metastasis and 8 (29.6%) with metastasis. HPV was detected in the cervical lesions of 74 patients (93.7%), but low expression of the HLA-G5 isoform was observed in all HPV-related cases. These findings are important; however, additional studies are necessary to identify the influence of HPV with HLA-G5 isoform expression on invasive cervical malignancies.

The prognosis after hematopoietic cell transplantation (HCT) for the treatment of leukemia or lymphoma in humans is influenced by donor-derived natural killer (NK) cells, which enhance the graft-versus-leukemia (GVL) effect. Such alloreactive killer cells can be generated in vivo after HCT if the donor expresses killer cell immunoglobulin-like receptors (KIRs), such as KIR2DL1, KIR2DL2/3, or KIR3DL1, for which the recipient lacks HLA class I ligands. We studied effector cells from 22 KIR/HLA-ligand mismatched and 14 KIR/HLA-ligand matched, primarily HLA-matched patient-donor pairs after allogeneic HCT. A novel 8-color flow cytometry panel allowed us to characterize effector-cell populations without "broadly reactive" inhibitory receptors such as CD94/NKG2A or LIR1. The numbers of such NKG2A(-) LIR1(-) NK cells increased following HCT in patients transplanted by KIR/HLA-ligand mismatched grafts, compared to KIR/HLA-ligand matched grafts, and in patients transplanted from donors of the A/B, compared to A/A, KIR haplotypes. NKG2A(-)LIR1(-) NK cells expressing only those inhibitory KIRs for which the patient had no HLA class I ligands could be stimulated by HLA class I-deficient cells to express CD107a. Thus, NKG2A(-)LIR1(-) NK cells may be important GVL effector cells following HCT, even in patients transplanted from HLA-matched donors., (Copyright (c) 2010 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to investigate classical MHC class I and nonclassical MHC (human leukocyte antigen-G [HLA-G]) expression in a large cohort of patients with endometrial cancer, to determine the prognostic value of these cell surface markers and their relation with clinicopathological variables. Tissue microarrays containing epithelial endometrial carcinoma tissue from 554 patients were stained for classical and nonclassical MHC class I using the following monoclonal antibodies: 4H84 (anti-HLA-G), beta2-m (anti-beta-2-microglobulin) and HC-10 (MHC class I antigen heavy chain). Expression data were linked to known clinicopathological characteristics and survival. HLA-G upregulation and MHC class I downregulation in neoplastic cells was observed in 40% and 48%, respectively. Nonendometrioid tumor type, advanced stage disease (FIGO stage > or = II) and poorly or undifferentiated tumors were associated with MHC class I downregulation. Absence of HLA-G expression was independently associated with MHC class I downregulation. In univariate analysis, MHC class I downregulation was a predictor of worse disease-specific survival. Prognostic unfavorable tumor characteristics were correlated with downregulation of MHC class I expression in endometrial cancer cells. Furthermore, downregulated MHC class I has a negative impact on disease-specific survival, observed in a large cohort of patients with endometrial cancer. As there seems to be a relation between classical and nonclassical MHC class I molecules (HLA-G), further research is warranted to unravel this regulatory mechanism.

Background: Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are severe, bullous cutaneous diseases with uncertain pathogenesis, although cytotoxic T cells seem to be involved. Natural killer (NK)-like activity has been found in blister infiltrates. Cytotoxic T lymphocytes (CTLs) with NK-like activity (NK-CTLs) have been shown to express T-cell receptors restricted by the HLA-Ib molecule HLA-E. Alternatively, the HLA-E-specific activating receptor CD94/NKG2C can trigger T-cell receptor-independent cytotoxicity in CTLs., Objective: Our aim was to test whether HLA-E expression sensitizes keratinocytes to killing by CTLs with NK-like activity and to explore the expression of activating receptors specific for HLA-E in blister cytotoxic lymphocytes., Methods: We used flow cytometry and immunohistochemistry to analyze HLA-E expression in keratinocytes from affected skin in patients with SJS, TEN, and other less severe drug-induced exanthemas. The expression of CD94/NKG2C was analyzed by means of flow cytometry in PBMCs and blister cells from patients. PBMCs and blister cells were analyzed for their ability to kill HLA-E-expressing cells. Involvement of CD94/NKG2C in triggering degranulation of cytolytic cells was explored by means of CD107a mobilization assays and standard cytotoxicity chromium release assays., Results: We found that keratinocytes from affected skin expressed HLA-E and that cell-surface HLA-E sensitizes keratinocytes to killing by CD94/NKG2C(+) CTLs. Frequencies of CD94/NKG2C(+) peripheral blood T and NK cells were increased in patients with SJS and TEN during the acute phase. Moreover, activated blister T and NK lymphocytes expressed CD94/NKG2C and were able to degranulate in response to HLA-E(+) cells in an NKG2C-dependent manner., Conclusion: CD94/NKG2C might be involved in triggering cytotoxic lymphocytes in patients with SJS and TEN.

Persistence of donor-specific anti-HLA antibodies (DSA) associated with antibody-mediated graft injuries following kidney transplantation predicts evolution toward chronic humoral rejection and reduced graft survival. Targeting plasma cells, the main antibody-producing cells, with the proteasome inhibitor bortezomib may be a promising desensitization strategy. We evaluated the in vivo efficacy of one cycle of bortezomib (1.3 mg/m(2)x 4 doses), used as the sole desensitization therapy, in four renal transplant recipients experiencing subacute antibody-mediated rejection with persisting DSA (>2000 [Mean Fluorescence Intensity] MFI). Bortezomib treatment did not significantly decrease DSA MFI within the 150-day posttreatment period in any patient. In addition, antivirus (HBV, VZV and HSV) antibody levels remained stable following treatment suggesting a lack of efficacy on long-lived plasma cells. In conclusion, one cycle of bortezomib alone does not decrease DSA levels in sensitized kidney transplant recipients in the time period studied. These results underscore the need to evaluate this new desensitization agent properly in prospective, randomized and well-controlled studies.

Total saponins of panax ginseng (TSPG) are the major active components in panax ginseng. Dendritic cells (DCs) play an active role in the immunological processes related to atherosclerosis. The purpose of this study was to determine the effect and possible mechanisms of TSPG on the maturation and immune function of DCs. Compared with those untreated, the DCs pre-treated with TSPG and then induced by oxidized-LDL exhibited a significantly lower expression of the maturation-associated markers of CD40, CD86, HLA-DR, and CD1a, together with an increased endocytosic function as well as decreased secretions of cytokine. However, silencing the expression of PPARgamma in DCs, the inhibitory effect of TSPG on the maturation DCs was significantly reduced. In conclusion, TSPG could inhibit the maturation of DCs induced by oxidized-LDL which suggests beneficial effects on atherosclerosis and this effect was partly dependent on the PPARgamma pathway at least., (Copyright 2010 Elsevier Inc. All rights reserved.)

Influenza virus type A (IAV) infections constitute an important economic burden and raise health-care problems. Host defense mechanisms usually clear IAV infections after a few days by exploiting a variety of cellular immune responses. However, increasing the production of immunosubversive molecules is a mechanism by which viruses escape host surveillance. In this regard, the nonclassical HLA class I molecule HLA-G displays strong tolerogenic properties. We show here that several strains of IAV differently upregulate HLA-G expression, at both the mRNA and protein levels, in alveolar epithelial cells. Thus the virulence of IAV may be caused by the capability of different strains to upregulate HLA-G allowing their escape from host immune responses.

HLA-G is a nonclassical MHC class I molecule with restricted normal tissue distribution, but whose expression is induced in pathologic situations such as cancer. In regard to the its immunosuppressive properties, it has been suggested that HLA-G could be a way for tumors to escape immunosurveillance. HLA-G has been described in almost all types of cancer, whatever their origins. Ovarian cancer is the second leading cause of death among women with gynecologic cancers, after breast cancer. The high mortality rate of this pathology is linked to its late discovery resulting from discreet symptomatology at early stages and the current paucity of highly sensitive and specific biomarkers. The aim of the present study was to analyze, in a French, retrospectively based study, whether HLA-G could be a marker for the detection of ovarian cancer and the prediction of clinical evolution. For this purpose, we looked for HLA-G expression in ovarian carcinoma lesions from low to high grade and stage, and we showed that HLA-G is selectively expressed in advanced-stage disease of high-grade histology.