Research progress on the role of exosome in rejection after lung transplantation / 器官移植

Rejection after lung transplantation, including acute rejection (AR) and chronic rejection manifested with chronic lung allograft dysfunction (CLAD), is the main factor affecting the long-term survival of allografts. Exosome, a type of extracellular nanovesicle for intercellular communication among eukaryotic cells, could carry complex biological information and participate in various physiological and pathological processes. Exosome has become a critical immune medium in rejection, regulates the incidence and development of rejection through multiple pathways, and also plays a key role in the monitoring and management of rejection. In this article, the type of rejection after lung transplantation, the mechanism underlying the role of exosome in regulating rejection, exosome acting as biomarkers and the application in rejection treatment were reviewed, aiming to provide a novel direction for comprehensive diagnosis and treatment of rejection following lung transplantation.

Preliminary study on the anti-tumor effect and mechanism of a novel fully human anti-LAG3 monoclonal antibody in vitro / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: The co-culture model of LAG3+Jurkat cells and tumor cells was constructed to investigate the anti-tumor effect and mechanism of a novel fully human anti-LAG3 monoclonal antibody in vitro. Methods: Jurkat cells were stimulated with PHA to simulate TIL, and the secretion of IL-2 was detected by ELISA to evaluate the degree of Jurkat cell activation. Meanwhile, FCM, Immunofluorescence and WB assays were employed to detect the expression of LAG3 in activated Jurkat cells and MHC classⅡmolecule（MHC-Ⅱ）, a LAG3 ligand, in HGC-27, MGC-803 and A549 tumor cells. The co-culture model of activated LAG3+Jurkat cells and tumor cells was constructed, and CCK-8 assays were employed to detect the killing efficiency of LAG3+Jurkat cells against tumor cells at different effector-target ratios and the effect of the anti-LAG3 antibody . The secretion levels of cytokines IL-2, IL-10 and TNF-α in supernatant of co-culture system were detected by ELISA. Results: After 48 h treatment, 2 μg/mL PHA exhibited no obvious cytotoxicity to Jurkat cells (P>0.05), but could significantly induce IL-2 secretion (P<0.01) and LAG3 expression (P<0.01), indicating activated LAG3+Jurkat cells were acquired. MGC-803 and A549 cells significantly expressed MHC-Ⅱ (P<0.01), but HGC-27 cells did not express MHC-Ⅱ (P>0.05). The co-culture model of LAG3+Jurkat cells and tumor cells was constructed at a effector-target ratio of 10∶1. The anti-LAG3 antibody could effectively enhance the killing efficiency of Jurkat cells against MHC-Ⅱ+ tumor cells (P<0.05). Further analysis revealed that the secretion levels of cytokines IL-2, IL-10 and TNF-α were increased in the co-culture supernatant of MHC-Ⅱ+ target cell group (all P<0.01). Conclusion: A co-culture model of LAG3+Jurkat cells and tumor cells was successfully constructed in vitro. The anti-LAG3 antibody might increase the killing effect of Jurkat cells against MGC-803 and A549 tumor cells through blocking LAG3/MHC-Ⅱ interaction, which may be related to the increased secretion levels of cytokines IL-2, IL-10 and TNF-α in the supernatant of co-culture system.

New progress on diagnosis and treatment of acute cellular rejection after lung transplantation / 器官移植

Acute cellular rejection (ACR) is a common complication after lung transplantation, which is mainly caused by the immune response of T lymphocytes recognizing the major histocompatibility complex on the cellular surface of grafts. It is currently considered as the main pattern of acute rejection. ACR is not only a direct cause of death of recipients, but also a high-risk factor for chronic rejection after lung transplantation. Nevertheless, it is a challenging task to deliver the diagnosis and treatment of ACR following lung transplantation. In this article, new progresses on the risk factors, pathogenesis, diagnosis and treatment of ACR in lung transplant recipients were summarized, aiming to improve the diagnostic and treatment efficiency of ACR and prolong the survival of recipients.

Effects of upregulation of CREB on proliferation, invasion and NK cell killing activity of esophageal adenocarcinoma / 中国医师杂志

Objective:To investigate the effects of upregulation of cAMP response element binding protein (CREB) on proliferation, invasion and natural killer (NK) cell killing activity of esophageal adenocarcinoma.Methods:23 patients with esophageal cancer treated in Shaanxi Provincial People′s Hospital from March 2017 to December 2019 were selected. The protein expression of CREB in esophageal adenocarcinoma and adjacent normal tissues was detected by immunohistochemistry; Esophageal adenocarcinoma cell line TE-10 was cultured in vitro. TE-10 cells transfected with si-NC were set as the control group and TE-10 cells transfected with si-CREB were set as the si-CREB group. Western blot was used to detect the protein level of CREB, MHC class Ⅰ chain-related A (MICA) and MHC class Ⅰ chain-related B (MICB); Flow cytometry was employed to detect the expression of MICA and MICB; clone formation experiment and Transwell were used to detect the proliferative and invasive ability of TE-10 cells; lactate dehydrogenase (LDH) releasing assay was used to detect cytotoxicity of NK cells against TE-10 cells. Results:The expression of CREB in esophageal adenocarcinoma tissue was higher than that in normal tissues adjacent to cancer; the protein level of CREB in esophageal cancer cell TE-10 was higher than that of human normal esophageal epithelial cells HEEC ( P<0.05). The proliferative and invasive ability of TE-10 cells in the si-CREB group was significant lower than that in the control group ( P<0.05), while the expression of MICA and MICB, the killing rate of NK cells on TE-10 cells was significant higher than that in the control group ( P<0.05). Conclusions:CREB was highly expressed in esophageal adenocarcinoma tissues and cells. Silencing CREB could inhibit the proliferation and invasion of esophageal adenocarcinoma cells, and enhance the killing sensitivity of NK cells to esophageal adenocarcinoma cells by up-regulating the expression of MICA and MICB.

Investigation of MHC gamma block C4A and C4B polymorphisms in unrelated hematopoietic stem cell transplantation

ABSTRACT Background: Immunological life-threatening complications frequently occur in post-hematopoietic stem cell transplantation (HSCT), despite matching recipient and donor (R/D) pairs for classical human leukocyte antigens (HLA). Studies have shown that R/D non-HLA disparities within the major histocompatibility complex (MHC) are associated with adverse effects post-HSCT. Methods: We investigated the impact of mismatches of single-nucleotide polymorphisms (SNPs) in C4A/C4B genes, for showing the highest diversity in the MHC gamma block, on 238 patients who underwent HLA 10/10 unrelated donor (URD) HSCT. The endpoints were acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD) and mortality. One hundred and twenty-nine R/D pairs had 23 C4-SNPs typed by PCR-SSP (Gamma-Type™v.1.0), and 109 R/D pairs had these 23 SNPs identified by next-generation sequencing (NGS) using the Illumina platform. Results: The percentage of patients who received HSC from HLA 10/10 donors with 1-7 mismatches was 42.9%. The R/D pairs were considered C4 mismatched when bearing at least one disparity. These mismatches were not found to be risk factors for aGVHD, cGVHD or mortality after unrelated HSCT when SNPs were analyzed together (matched or mm ≥ 1), independently or according to the percentage of incompatibilities (full match for 23 SNPs; 1-3 mm and >3 mm). An exception was the association between 1-3 mismatches at the composite of SNPs C13193/T14952/T19588 with the development of aGVHD (P = 0.012) and with grades III-IV of this disease (P = 0.004). Conclusion: Our data are not consistent with the hypothesis that disparities in C4A/C4B SNPs increase the risks of post-HSCT adverse effects for the endpoints investigated in this study.

Association between NDO-LID and PGL-1 for leprosy and class I and II human leukocyte antigen alleles in an indigenous community in Southwest Amazon

The frequencies of the Human leukocyte antigen (HLA) alleles in the Puyanawa indigenous reserve population and their association with the NDO-LID and ELISA PGL-1 rapid serological test was assessed. This was a cross-sectional study with an epidemiological clinical design conducted in two indigenous communities in the state of Acre, Brazil. Blood was collected in a tube with EDTA to identify HLA alleles and perform serological tests. DNA was obtained using the salting out procedure. The LabType™ technique (One-Lambda-USA) was used for HLA class I (loci A*, B* and C*) and II (loci DRB1*, DQA1* and DQB1*) typing. Allele frequency was obtained by direct count, and the chi-square test was used to assess the association with the NDO-LID and PGL-1 tests. The most frequent alleles in the two communities were: HLA-A*02:01, HLA-B*40:02, HLA-DRB1*16:02, HLA-DQA1*05:05 and HLA-DQB1*03:01. The allele HLA-C*04:01 was the most common in the Barão community, and the allele HLA-C*07:01 in Ipiranga. Among individuals who presented seropositivity to the NDO-LID test, the association with alleles HLA-A*02 (43.18% vs 24.8%, p = 0.03, OR = 2.35) and HLA-B*53 (6.83% vs 0.0%, p = 0.03, OR = 8.95) was observed in the Barão community. HLA-B*15 was associated with non-seroconversion to the NDO-LID test in Ipiranga. In both communities, HLA-B*40 and HLA-C*03 were associated with positive serological response to ELISA PGL-1. The HLA class I and II alleles most frequently found in this study have already been described among Terena indigenous groups, and HLA class I contributes to seroconversion to NDO-LID and PGL-1 tests in inhabitants of the Barão and Ipiranga communities(AU).

Identification of T-Cell Epitopes in Proteins of Novel Human Coronavirus, SARS-Cov-2 for Vaccine Development

Recently, a novel human coronavirus, SARS-CoV-2 led to a worldwide serious health concern, causing severe respiratory tract infections in humans. It is the third highly pathogenic and transmissible coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in humans. The source of origin, transmission to humans and mechanisms associated with the pathogenicity of SARS-CoV-2 are not clear yet, however, its resemblance with SARS-CoV and several other bat coronaviruses was recently confirmed through genome sequencing related studies. It has been an emergent need to develop a potent and adequate number of drugs and vaccines to control the spread of coronavirus. We have screened the specific proteins such as ORF1ab polyprotein, surface glycoprotein, membrane glycoprotein and nucleocapsid phosphoprotein of SARS-CoV-2 for identification of T-cell epitopes using immunoinformatics tools. In this study we used different bioinformatics tools for analysis of genome and proteome. We retrieved gene sequence from NCBI. The expected molecular weight and isoelectric point (pI) values were also verified using Generunner and ExPaSy. These epitopes have showed the highest binding affinity with major histocompatibility complex (MHC) class I and II molecules. These findings may be useful as an immunodiagnostic tool for the development of peptide based novel vaccines.

Expression of MHCⅠ genes in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila / 生物工程学报

The aim of this study was to investigate the expression of MHCⅠ gene in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila (Ah), and to provide evidence for revealing the anti-infective immune response mechanism of amphibians. The experimental animal model of Aeromonas hydrophila infection was first constructed, and the pathological changes were observed by HE staining. The MHCⅠ gene α1+α2 peptide binding region of Rana dybowskii was cloned by RT-PCR and analyzed by bioinformatics. Real-time PCR was used to detect the transcription level of MHCⅠ in different tissues under Ah stress. After Ah infection, the skin, liver and muscle tissues showed signs of cell structure disappearance and texture disorder. The MHCⅠ gene α1+α2 peptide binding region fragment was 494 bp, encoding 164 amino acids, and homology with amphibians. Above 77%, the homology with mammals was as low as 14.96%, indicating that the α1+α2 region of MHC gene was less conserved among different species. The results of real-time PCR show that the liver, spleen and kidney of the experimental group were under Ah stress. The transcript levels of MHCⅠ gene in skin and muscle tissues were higher than those in the control group at 72 h, but the time to peak of each tissue was different (P<0.01), indicating that the response time of MHCⅠ gene in different tissues was different under Ah stress. This study provides a reference for further exploring the immune function of MHC molecules in anti-infection.

Rice bran hydrolysates induce immunomodulatory effects by suppression of chemotaxis, and modulation of cytokine release and cell-mediated cytotoxicity

Objective: To evaluate the immunomodulatory effects of rice bran hydrolysates on cultured immune cells and their underlying mechanism. Methods: Rice bran hydrolysates were prepared from pigmented rice (Oryza sativa L.) by hydrothermolysis and protease digestion. Rice bran hydrolysates were assayed for phenolic content and antioxidant activity. Cell proliferation of Jurkat, THP-1 and peripheral blood mononuclear cells (PBMC) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Chemotaxis was evaluated by transwell chamber methods. Immunoadherence of THP-1 was performed on cultured human umbilical vein endothelial cells (HUVEC). Cytokine released from PBMC was measured by ELISA assay kits. Lymphocyte-mediated cytotoxicity was carried out on KKU-452 cells. Proteins associated with immunomodulation were analyzed by Western immunoblotting assay. Results: Rice bran hydrolysates were rich in phenolic compounds, such as ferulic acid, catechin, quercetin, and quercetin glycosides. Rice bran hydrolysates suppressed phytohemagglutinin (PHA)-stimulated proliferation of PBMC and Jurkat cells, chemotaxis of Jurkat and THP-1 cells, and immunoadherence of THP-1 on HUVEC cultured cells. The cellular mechanism of rice bran hydrolysates involved the activation of AMPK as well as suppression of mTOR, NF-κB and VCAM-1. Rice bran hydrolysates potentiated PBMC on the PHA-stimulated release of IL-2, TNF-α, and IL-4, and enhanced PHA-induced non-MHC-restricted cytotoxicity on KKU-452 cancer cells. Conclusions: The immunomodulatory effect of phytochemicals derived from rice bran hydrolysates suggests its therapeutic potential for further investigation.

Mucosal-associated invariant T cells and tumors / 中国药理学通报

Mucosal-assooiated invariant T(MAIT) cells are an evolutionarily highly conserved T lymphocyte subsets with the innate functions similar to innate natural killer T(iNKT) cells. MAIT cells are defined by their invariant T cell receptors (TCR)-alpha chain and restrictive major histocompatibility complex (MHC) related protein-! (MR1) , and identify antigens through the MR1, secreting a variety of cytokines after being activated, directly or indirectly involved in the body's immune re-sponses. MAIT cells are also abundant in human peripheral blood and many tissues. They are closely related to the occurrence and development of various infectious diseases, autoimmune diseases and malignant tumors. This article mainly reviews the research on MAIT cells in tumor diseases.

Samsum ant venom modulates the immune response and redox status at the acute toxic dose in vivo

Background:Ant venoms express surface molecules that participate in antigen presentation involving pro- and anti-inflammatory cytokines. This work aims to investigate the expression of MHC-II, CD80 and CD86 on the polymorphonuclear cells (PMNs) in rats injected with samsum ant venom (SAV).Methods:Rats were divided into three groups - control, SAV-treated (intraperitoneal route, 600 μg/kg), and SAV-treated (subcutaneous route, 600 μg/kg). After five doses, animals were euthanized and samples collected for analysis.Results:The subcutaneous SAV-trated rats presented decreased levels of glutathione with increased cholesterol and triglyceride levels. Intraperitoneal SAV-treated animals displayed significantly reduced concentrations of both IFN-γ and IL-17 in comparison with the control group. However, intraperitoneal and subcutaneous SAV-treated rats were able to upregulate the expressions of MHC-II, CD80 and CD86 on PMNs in comparison with the control respectively. The histological examination showed severe lymphocyte depletion in the splenic white pulp of the intraperitoneal SAV-injected rats.Conclusion:Stimulation of PMNs by SAV leads to upregulation of MHC-II, CD 80, and CD 86, which plays critical roles in antigen presentation and consequently proliferation of T-cells. Subcutaneous route was more efficient than intraperitoneal by elevating MHC-II, CD80 and CD86 expression, disturbing oxidative stability and increasing lipogram concentration.

A surface antigen of Orientia tsutsugamushi activates human monocyte-derived dendritic cells via nuclear factor-kB & p38 mitogen-activated protein kinase pathways

Background & objectives: Scrub typhus is a chigger-borne disease caused by Orientia tsutsugamushi. The immunological reactions to O. tsutsugamushi infection are not completely understood. In this study, we investigated the response of dendritic cells (DCs) to a major 56-kDa scrub typhus antigen Sta56. Methods: Monocyte-derived human DCs were incubated with different concentrations of recombinant Sta56 and analyzed for maturation based on phagocytic capacity, the ability to induce T-cell proliferation, expression of surface markers, cytokine secretion and activation of toll-like receptor (TLR)-dependent signalling pathways. Results: Treatment of DCs with Sta56 induced cell surface expression of CD80, CD83, CD86 and MHC Class II increased the production of interleukin-12 (IL-12) p40, IL-12 p70 and IL-10 and decreased DC phagocytic capacity. Furthermore, Sta56 increased the ability of DCs to activate T-cell proliferation and interferon-? secretion. TLR4-specific antibodies neutralized Sta56-elicited effects on DC maturation, suggesting direct interaction between Sta56 and TLR4. Moreover, Sta56 activated nuclear factor (NF)-?B and p38 mitogen-activated protein kinase (MAPK) signalling as evidenced by decrease in Sta56-induced cytokine production and surface marker expression by specific inhibitors helenalin and SB203580, respectively, and increase in I?B? and p38 phosphorylation and NF-?B-DNA binding. Interpretation & conclusions: Our results showed that the surface antigen of O. tsutsugamushi activated DCs through interaction with TLR4 and activation of MAPK and NF-?B signalling, suggesting Sta56 as a potential candidate molecule for the development of vaccine against scrub typhus.

Associação entre esclerose múltipla e alelos HLA-DRB1 em uma população miscigenada de Salvador, Ba, Brasil / Association between multiple sclerosis and HLA-DRB1 alleles in an admixed population of Salvador, Ba, Brazil

Introdução: a esclerose múltipla é uma doença que afeta preferencialmente o sistema nervoso central de mulheres jovens, causandolhes graus variáveis de incapacidades física e cognitiva. Etiologicamente associa fatores ambientais, biológicos, sócio-econômicos e genéticos, como por exemplo genes do MHC classe II, especialmente os alelos HLA-DRB1*. Objetivo: determinar a frequência dos alelos HLA DRB1* em portadores de esclerose múltipla atendidos no centro de referência do C.H.U.P.E.S, UFBA, no período de outubro de 2014 a abril de 2015 e associá-las a variáveis clínico-demográficas. Metodologia: estudo do tipo caso-controle, aprovado pelo comitê de ética da Faculdade de medicina da Universidade Federal da Bahia (CAAE: 3517134.0.0000.5577), que envolveu uma amostra de conveniência composta por 97 indivíduos, cujos dados clínico-demográficos foram coletados através de questionário desenvolvido para a pesquisa. A genotipagem dos alelos HLA-DRB1* foi realizada através da técnica HLA-DR SSO GenotypingTest. Resultados: a análise quantitativa revelou perfil genotípico do tipo HLA-DRB1*15 (20,5%), em mulheres (83,0%), das raças/etnias negra ou parda (75,0%), com faixa etária entre 30 e 39 anos (28,0%). Houve predomínio da forma clínica surtoremissiva da doença (76,0%), dentre os doentes com idade mais avançada (55,0%), sem permanência de sequela clínica (70,0%) e que usavam algum tipo de Interferon (58,0%). A análise qualitativa indicou maiores frequências, na forma progressiva de esclerose múltipla dos grupos alélicos HLA-DRB1*12 (22,0%), e dos alelos HLA-DRB1*13 (12,6%)e HLA-DRB1*15 (22,0%) naqueles indivíduos com a forma surtoremissiva. Negros e pardos demonstraram maior prevalência do alelo HLA-DRB1*15 (24,0%), enquanto que nos brancos houve maior prevalência do alelo HLA-DRB1*07 (20,0%). Conclusão: forte associação entre as frequências alélicas, esclerose múltipla e as variáveis raça/etnia e forma clínica da doença.

Determinación in silico de las propiedades inmunogénicas de la glicoproteína E de Zika virus / In silico determination of immunogenic properties of glycoprotein E from Zika Virus

Introducción: La infección por Zika virus (ZIKV) ha sido asociada a múltiples complicaciones y nuevas formas de transmisión. La descripción del genoma y la estructura cristalizada permiten desarrollar análisis moleculares, incluyendo las propiedades inmunológicas. Objetivos: En este trabajo, se analiza a la glicoproteína E de ZIKV, con el fin de determinar su utilidad en la creación de una vacuna proteica recombinante. Métodos: Se analizó la glicoproteína E, por medio del software DNASTAR, en base a su antigenicidad de epítopos de células B y MHC-II, estructura secundaria, hidrofilizada, flexibilidad y accesibilidad a solvente en el virión maduro e hidratado. Resultados: Se identificaron 14 sitios antigénicos para células B, de los cuales, 7 comparten su antigenicidad para MHC-II. Al tomar en cuenta los demás parámetros analizados, los sitios se reducen a 3, con longitudes de 13, 9 y 5 aminoácidos. Conclusiones: La glicoproteína E de ZIKV podría desencadenar una respuesta inmune T-dependiente, por tanto, ser útil para la creación de una vacuna proteica recombinante.

Introduction: Zika virus (ZIKV) infection have been associated with multiple complications and new ways of transmission. The description of the genome and the crystalized structure allow the performance of molecular analysis, including immunological properties. Objectives: In this paper, we analyze glycoprotein E from ZIKV to determine its utility in the development of a recombinant protein vaccine. Methods: The protein was analyzed with the software DNASTAR, through the following properties: B cells and MHC-II antigenicity, secondary structure, hydrophilicity, flexibility and solvent-accessibility in the mature and hydrated virion. Results: We identified 14 antigenic sites with B-cells antigenicity, 7 of which shared the antigenicity for MHC-II. Considering other parameters analyzed, sites were reduced to 3, with length of 13, 9 and 5 amino acids. Conclusions: Glycoprotein E, from ZIKV, could trigger a T-dependent immune response, and therefore, may be useful in the creation of a recombinant protein vaccine.

High expression of MICA/B prolongs disease-free survival in patients with HER2positive breast cancer / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the relationship between expression of MICA/B (MHC class I chain-related proteinA/B) and disease-free survival (DFS) of patients with HER2+(human epidermal growth factor receptor 2) breast cancer tissue. Methods: Twenty six cases of corresponding para-cancerous tissue and 100 cases of HER2+ breast cancer tissue that preserved in wax at Zhengzhou People’ s Hospital Affiliated to Southern Medical University from January 2009 to June 2010 were collected for this study. Expression of MICA/ B in these tissue samples was detected by immunohistochemistry; and the relationship between MICA/B expression with clinicopathologic features as well as DFS was analyzed with Kaplan-Meier survival curve. Results: The expression of MICA/B in adjacent paracancerous tissues was negative (0/26), however, it was highly positive in cancer tissues (92/100), and the percentage with high expression was 65%(65/100), the difference was significant (P<0.05). High MICA/B expression rate in stage I was significantly higher than that in stage Ⅱ-Ⅲ (77.55% vs 52.94%， P<0.05), and the high expression rate in stage T1 was also significantly higher than that in stage T2-T4 (75.00% vs 52.27%， P<0.05). High MICA/B expression rate in ER+, PR+ group (with positive number≥1%) was significantly lower than that in ER- , PR-group (ER： 52.38% vs 74.14%，PR： 51.35% vs 73.02%， all P<0.05). MICA/B expression was correlated with clinical stages, the expression of ER, PR and tumor size (all P<0.05), but not associated with menopausal status, histological grade and lymph node metastasis (all P>0.05). Over-expression of MICA/B was closely associated with much better 6-year DFS rate in patients no matter with or without targeted therapy (the targeted group: 90.6% vs 72.2%; the untargeted group: 78.4% vs 58.8%, all P<0.05). Conclusion: Over-expression of MICA/B in HER2+ breast cancer tissue is closely related to DFS, which may be served as a potential prognosis indicator for patients with HER2+ breast cancer.

Analysis of swine leukocyte antigen class I gene profiles and porcine endogenous retrovirus viremia level in a transgenic porcine herd inbred for xenotransplantation research

Molecular characterization of swine leukocyte antigen (SLA) genes is important for elucidating the immune responses between swine-donor and human-recipient in xenotransplantation. Examination of associations between alleles of SLA class I genes, type of pig genetic modification, porcine endogenous retrovirus (PERV) viral titer, and PERV subtypes may shed light on the nature of xenograft acceptance or rejection and the safety of xenotransplantation. No significant difference in PERV gag RNA level between transgenic and non-transgenic pigs was noted; likewise, the type of applied transgene had no impact on PERV viremia. SLA-1 gene profile type may correspond with PERV level in blood and thereby influence infectiveness. Screening of pigs should provide selection of animals with low PERV expression and exclusion of specimens with PERV-C in the genome due to possible recombination between A and C subtypes, which may lead to autoinfection. Presence of PERV-C integrated in the genome was detected in 31.25% of specimens, but statistically significant increased viremia in specimens with PERV-C was not observed. There is a need for multidirectional molecular characterization (SLA typing, viremia estimation, and PERV subtype screening) of animals intended for xenotransplantation research in the interest of xeno-recipient safety.

Recent advances in pMHC multimer technology / 中国免疫学杂志

To overcome the intrinsic low affinity between peptide bound major histocompatibility complex(pMHC) and T cell receptors (TCRs) on T cell surface,pMHC can be multimerized to enhance its avidity to TCRs.Since 20 years ago pMHC tetramer was first applied in the detection of antigen specific T cells,it has become one of the most important immunoassay tools.Recently,pMHC multimers have been significantly improved over the original tetramer.pMHC multimers with higher valence have been produced in order to enhance detection sensitivity.Additionally,reversible pMHC multimers,which can be released from T cell surface to avoid potential damage to T cells,also have been applied in the isolation of antigen specific T cells.As a class of molecular tools,pMHC multimers play an important role in immunoassays and immunotherapies.A good knowledge and effective utilization of those tools will be greatly helpful in scientific and clinical applications.

Research on polymorphism of MICA genes in patients with type 1 diabetes mellitus in the Han and Lipopulations in Hainan province / 中华检验医学杂志

Objective To investigate the genetic diversity of MICA, and to analyze the correlation between genetic polymorphisms of MICA and T1DM in population of Han and Li nationalities in Hainan province.Methods This study was performed as a case-control study.Fifty-five individuals with T1DM and Fifty-five healthy controls of Han and Li nationalities from Wuzhishan, Lingshui, Qiongzhong, Baisha, Ledong,Changjiang, Dongfang and Haikou regions in Hainan province(35 Male,20 Female of T1DM of Han;28 Male,27 Female of healthy controls of Han; 33 Male,22 Female of T1DM of Li; 28 Male, 27 Female of healthy controls of Li), were enrolled for the study.MICA allelic variation was analyzed by sequencing-based typing(PCR-SBT).Fisher′s exact test was performed to determine the statistical significance of the distribution and allele frequency of MICA.Results In healthy population,11 MICA-sequence and 5 MICA-STR alleles were found in Han nationality, while 13 MICA-sequence and 5 MICA-STR alleles were detected in Li nationality.The MICA-sequence allele MICA*008:01 and the MICA-STR allele MICA-A5 were most frequently observed in Han nationality[30.85%(29/94)and 41.49%(39/94), respectively],while MICA*002:01 and A4 were the most common in Li nationality[21.57%(22/102) and 36%(36/100), respectively].Among patients with T1DM, 10 MICA-sequence and 5 MICA-STR alleles were detected in Han, and 9 MICA-sequence and 5 MICA-STR alleles were found in Li.MICA*002:01 and A9 were most frequently observed in Han[29%(29/100),29.29%(29/99),respectively], while MICA*012:01, MICA*002:01 and the A4 were the most common in Li[21.15%(22/104), 21.15%(22/104),38.24%(39/102), respectively].The allelic frequency of MICA*002:01, MICA*010, MICA-A5, MICA-A6 and MICA-A9 between the healthy population and T 1DM patients of Han nationality(5.32%,22.34%,41.49 %,9.58%,6.38%, respectively in healthy population;29%,7%, 26.26%,2.02%,29.29%, respectively in T1DM patients), exist significant difference(χ2value were 18.799,9.233,5.218,5.197,16.762, respectively.P value were 0.000,0.002, 0.025,0.024,0.000, respectively.all P<0.05),while no significant difference(all P>0.05)between the healthy population and T1DM patients of Li nationality.Conclusions The most common MICA alleles were MICA*008:01 and MICA-A5 in healthy population of Han nationality, while MICA*002:01 and MICA-A4 in healthy population of Li nationality.MICA*002:01 and MICA-A9 were high frequency in T1DM patients of Han population,while the MICA*010,MICA-A5 and MICA-A6 were low frequency.There was not any MICA alleles associated with T1DM in Li nationality.

Isolation, culture, characterization and cryopreservation of stem cells derived from amniotic mesenchymal layer and umbilical cord tissue of bovine fetuses / Isolamento, cultura, caracterização e criopreservação de células tronco derivadas de camada amniótica mesenquimal e de tecido do cordão umbilical de fetuses bovinos

Stem cells are undifferentiated cells with a high proliferation potential. These cells can be characterized by their in vivo ability to self-renew and to differentiate into specialized cell lines. The most used stem cell types, in both human and veterinary fields, are the mesenchymal stem cells (MSC) derived from bone marrow and adipose tissue. Nowadays, there is a great interest in using stem cells derived from fetal tissues, such as amniotic membrane (AM) and umbilical cord tissue (UCT), which can be obtained non-invasively at delivery time. Due to the scarcity of studies in bovine species, the aim of this study was to isolate, characterize, differentiate and cryopreserve MSC derived from the mesenchymal layer of amniotic membrane (AM), for the first time, and umbilical cord tissue (UCT) of dairy cow neonates after assisted delivery (AD) and from fetus at initial third of pregnancy (IT) obtained in slaughterhouse. Cells were isolated by enzymatic digestion of the tissue fragments with 0.1% collagenase solution. Six samples of AM and UCT at delivery time and six samples of AM and UCT at first trimester of pregnancy were subjected to morphology evaluation, imunophenotype characterization, in vitro osteogenic, adipogenic and chondrogenic differentiation and viability analysis after cryopreservation. All samples showed adherence to plastic and fibroblast-like morphology. Immunocytochemistry revealed expression of CD 44, NANOG and OCT-4 and lack of expression of MHC II in MSC from all samples. Flow cytometry demonstrated that cells from all samples expressed CD 44, did not or low expressed CD 34 (AM: IT-0.3%a, AD-3.4%b; UCT: 0.4%, 1.4%) and MHC II (AM: IT-1.05%a, AD-9.7%b; UCT: IT-0.7%a, AD-5.7%b). They were also capable of trilineage mesenchymal differentiation and showed 80% viability after cryopreservation. According to the results, bovine AM and UCT-derived cells, either obtained at delivery time or from slaughterhouse, are a painless and non-invasive source of MSC and can be used for stem cell banking.(AU)

As células tronco mesenquimais (CTMs) estão presentes na maioria dos tecidos adultos e possuem grande capacidade de multiplicação. Quando cultivadas in vitro são capazes de se auto renovar e dar origem a novos tipos celulares. As células tronco mais utilizadas, tanto na medicina humana como na medicina veterinária são as células tronco mesenquimais derivadas da medula óssea e do tecido adiposo. Atualmente, uma grande tendência para a utilização de CTMs obtidas de tecidos fetais, como a membrana amniótica (MA), matriz extravascular do cordão umbilical (TCU) e sangue do cordão umbilical (SCU) pode ser observada, já que estas fontes podem ser colhidas no momento do parto por uma técnica não invasiva. Dessa forma, o objetivo deste estudo foi isolar, caracterizar, diferenciar e criopreservar CTMs obtidas de MA e TCU de fetos bovinos colhidos no momento do parto e de fetos do terço inicial da gestação em abatedouro-frigorífico. As células foram recuperadas por meio de digestão enzimática tecidual, realizada com solução de colagenase 0,1%. Foram colhidas amostras de MA e TCU no momento do parto (n=6) e de MA e TCU no terço inicial de gestação (n=6), as quais foram submetidas às análises morfológicas, imunofenotípica por imunocitoquímica e citometria de fluxo, diferenciações in vitro nas linhagens osteogênica, adipogênica e condrogênica e ainda, avaliação da viabilidade após a criopreservação por citometria de fluxo. Todas as amostras dos diferentes grupos demonstraram adesão ao plástico e morfologia fibroblastóide. No ensaio imunocitoquímico todas as amostras foram imunomarcadas para CD44, NANOG e Oct-4, com ausência de marcação para MHC II. Na análise imunofenotipica por citometria de fluxo, todas as amostras apresentaram marcação para CD44, ausência de marcação para ou baixíssima expressão de CD34 (MA: TI-0,3%a, PA-3.4%b; TCU: TI-0,4%, PA-1.4%) e nula ou baixa expressão de MHC II (MA: TI-1.5%a, PA-9.7%b; UCT: TI-0.7%a, PA-5.7%b. Apresentaram também capacidade de diferenciação in vitro nas três linhagens mesodermais e quando analisadas pós criopreservação por citometria de fluxo, todas as amostras apresentaram viabilidade de 80%. Estes resultados indicam que MA e TCU, obtidos tanto no momento de parto como em abatedouro, de fetos bovinos podem ser utilizados como fonte não invasiva e indolor de CTMs e possibilitam a formação de bancos de armazenamento de células.(AU)

Heterogeneous Nuclear Ribonucleoprotein A2B1 Exerts a Regulatory Role in Lipopolysaccharide-stimulated 38B9 B Cell Activation

Major histocompatibility complex (MHC) class II molecules, which are recognized for their primary function of presenting an antigen to the T cell receptor, are involved in various signaling pathways in B cell activation. We identified heterogeneous nuclear ribonucleoprotein (hnRNP) A2B1 as an MHC class II molecule-associated protein involved in MHC class II-mediated signal transduction in lipopolysaccharide (LPS)-stimulated 38B9 B cells. Although the function of hnRNP A2B1 in the nucleus is primarily known, the level of hnRNP A2B1 in the cytoplasm was increased in LPS-stimulated 38B9 cells, while it was not detected in the cytoplasm of non-treated 38B9 cells. The silencing of hnRNP A2B1 expression using siRNA disturbed B cell maturation by regulation of mitogen-activated protein kinase signaling, NF-κB activation, and protein kinase B activation. These results suggest that hnRNP A2B1 is associated with MHC class II molecules and is involved in B cell activation signaling pathways in LPS-stimulated 38B9 cells.