OBJECTIVEThis review focuses on the current knowledge on the implication and significance of beta 2 microglobulin (β2M), a conservative immune molecule in vertebrate.

DATA SOURCESThe data used in this review were obtained from PubMed up to October 2015. Terms of β2M, immune response, and infection were used in the search.

STUDY SELECTIONSArticles related to β2M were retrieved and reviewed. Articles focusing on the characteristic and function of β2M were selected. The exclusion criteria of articles were that the studies on β2M-related molecules.

RESULTSβ2M is critical for the immune surveillance and modulation in vertebrate animals. The dysregulation of β2M is associated with multiple diseases, including endogenous and infectious diseases. β2M could directly participate in the development of cancer cells, and the level of β2M is deemed as a prognostic marker for several malignancies. It also involves in forming major histocompatibility complex (MHC class I or MHC I) or like heterodimers, covering from antigen presentation to immune homeostasis.

CONCLUSIONSBased on the characteristic of β2M, it or its signaling pathway has been targeted as biomedical or therapeutic tools. Moreover, β2M is highly conserved among different species, and overall structures are virtually identical, implying the versatility of β2M on applications.

Antigens, CD1 ; physiology ; Hemochromatosis Protein ; analysis ; Histocompatibility Antigens Class I ; physiology ; Humans ; Receptors, Fc ; physiology ; beta 2-Microglobulin ; blood ; chemistry ; deficiency ; physiology

BACKGROUNDHumoral immunity is an important factor for long-term survival of renal allograft. Here we performed a four-year follow-up to explore the clinical significance of monitoring anti-human leukocyte antigens (HLA) and anti-major histocompatibility complex class I-related chain A (MICA) antibody expression after kidney transplantation.

METHODSWe obtained serial serum samples from 84 kidney transplant patients over a four-year period. All patients were followed up at least 6 months after transplantation and had at least two follow-up points. Anti-HLA and anti-MICA antibody titres and serum creatinine (SCr) levels were evaluated at each follow-up. Patients were divided into 4 groups: HLA(+) MICA(-), HLA(-)MICA(+), HLA(+)MICA(+) and HLA(-)MICA(-). The impact of post-transplant antibody level on kidney allograft function was evaluated.

RESULTSAntibodies were detected in 38.1% (32/84) of the renal allograft recipients. HLA, MICA and HLA+MICA expression was observed in 18.89%, 14.44% and 5.93% of the recipients respectively. The most frequent anti-HLA and anti-MICA specific antibodies identified were A11, A24, A29, A32, A33, A80; B7, B13, B37; DR17, DR12, DR18, DR52, DR53, DR1, DR4, DR9, DR51; DQ7, DQ4, DQ8, DQ2, DQ9, DQ5, DQ6 and MICA02, MICA18, MICA19, MICA07, MICA27. As the time after transplantation elapsed, more recipients developed de novo antibody expression. Total 11.91% (10/84) of the recipients had de novo antibody expression during the follow up. The average level of SCr and the percentage of recipients with abnormal allograft function were significantly higher in recipients with anti-HLA and/or anti-MICA antibody expression than those without. The appearance of anti-HLA and anti-MICA antibody expression always preceded the increase in SCr value.

CONCLUSIONSAnti-HLA and anti-MICA antibody expression has predictive value for early and late allograft dysfunction. The presence of donor specific antibody is detrimental to graft function and graft survival.

Female ; Follow-Up Studies ; Graft Survival ; HLA Antigens ; immunology ; Histocompatibility Antigens Class I ; immunology ; Humans ; Isoantibodies ; analysis ; Kidney Transplantation ; Male ; Minor Histocompatibility Antigens

Serum levels of soluble MHC class I-related chain A (sMICA) are related with the prognosis of various types of cancer; however, few studies on the prognostic value of sMICA in hepatocellular carcinoma (HCC) have been reported. In this study, we retrospectively investigated the relationship between sMICA levels and clinical features of advanced HCC, and we assessed the prognostic value of sMICA in advanced HCC. Furthermore, the relationship of serum sMICA levels and natural killer group 2, member D (NKG2D) expression on natural killer (NK) cells was also evaluated. We detected sMICA levels in the serum of 60 advanced HCC patients using enzyme-linked immunosorbent assay (ELISA) and measured expression levels of NKG2D on NK cells using flow cytometry. We found that serum sMICA levels in HCC patients were in the range of 0.10-6.21 ng/mL. Chi-square analyses showed that sMICA level was significantly related with only tumor size. Survival analysis showed that a high sMICA level was significantly related with poor prognosis among HCC patients. Multivariate analyses indicated that sMICA was an independent prognostic factor. In addition, the levels of CD56+NKG2D+ NK cells were within the range of 11.2%-55.4%, and correlation analyses indicated that sMICA level was negatively correlated with the level of NKG2D+ NK cells. Our results suggest that serum sMICA levels may be an independent prognostic factor for advanced HCC.
Adult ; Carcinoma, Hepatocellular ; blood ; immunology ; pathology ; Female ; Histocompatibility Antigens Class I ; blood ; Humans ; Killer Cells, Natural ; immunology ; metabolism ; Liver Neoplasms ; blood ; immunology ; pathology ; Male ; Middle Aged ; Multivariate Analysis ; NK Cell Lectin-Like Receptor Subfamily K ; metabolism ; Neoplasm Staging ; Retrospective Studies ; Survival Rate ; Tumor Burden

OBJECTIVETo establish a stable and large-scale bi-directional sequencing platform for genotyping MICA gene exons 2 to 4, and to analyze single nucleotide polymorphisms(SNP) of the region.

METHODSPrimers for particular alleles of MICA gene exons 2 to 5 were designed. Optimal conditions for PCR amplification and sequencing reaction were explored. A commercialized one-way sequencing kit for MICA allele was used as a parallel control. Four samples carrying a MICA *010 allele were subjected to cloning and haplotype sequencing.

RESULTSResults of MICA allele typing of 100 samples for a parallel control group were confirmed by the establish method. Twenty-two SNP in MICA gene exons 2 to 4 were detected in Chinese population. Two novel allelic sequences were accepted by GenBank and IMGT/HLA database and officially named as MICA*065 and MICA*066 by the WHO Nomenclature Committee. A novel SNP in MICA gene intron 3 was discovered, with allelic sequence submitted to GenBank and IMGT/HLA database.

CONCLUSIONThe bi-directional sequencing genotyping platform may be applied for large-scale study of MICA allelic polymorphisms, tissue typing, organ transplantation and disease research.

Adult ; Base Sequence ; Exons ; Female ; Genotyping Techniques ; Histocompatibility Antigens Class I ; genetics ; Humans ; Male ; Molecular Sequence Data ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA

OBJECTIVETo analyze the full nucleotide sequence of a null allele of major histocompatibility complex class I chain-related gene (MICA).

METHODSA sequence-based typing method was used to determine the nucleotide sequence of the MICA gene. Potential alleles were identified with a computer program.

RESULTSThe identified allele has possessed a sequence similar to that of MICA*027 except for a C→T substitution at position 184 in codon 62 (CAG→TAG) of exon 2. As a stop codon, this may result in a truncated protein.

CONCLUSIONA null allele of MICA gene has been identified. The sequence has been submitted to the Genbank nucleotide sequence database (submission No. HWS10011131), which was officially named as MICA*063N by the WHO Nomenclature Committee in October 2010.

Alleles ; Base Sequence ; Codon, Terminator ; Exons ; Female ; Histocompatibility Antigens Class I ; genetics ; Humans ; Middle Aged ; Molecular Sequence Data ; Sequence Analysis ; methods

BACKGROUNDMany types of human tumors can suppress the immune system to enhance their survival. Loss or down-regulation of human leukocyte antigens (HLA) class I on tumors is considered to be a major mechanism of tumor immune escape. Our previous studies found that HLA class I on peripheral-blood mononuclear cells was significantly lower in gastric cancer patients. The present study made an analysis of HLA class I expression on peripheral-blood T lymphocytes and NK cells from subjects of Lijiadian village, a village with high-incidence gastrointestinal tumor.

METHODSA total of 181 villagers from Lijiadian village and 153 normal controls from the Department of Health Examination Center were enrolled in this study. Using a multi-tumor markers detection system, these villagers were divided into two groups: high-risk group (tumor markers positive group) and low-risk group (tumor markers negative group). The percentage of T lymphocytes and NK cells and levels of HLA class I on their surface were determined in these subjects by flow cytometry.

RESULTSPercentages of T lymphocytes and NK cells in peripheral-blood mononuclear cells did not vary with age. The expression level of HLA class I on peripheral T lymphocytes and NK cells was not affected by age or gender, but was significantly down-regulated in Lijiadian villagers (P < 0.05), especially on the surface of NK cells (P < 0.01). Compared with the low-risk group, there was a significant reduction of HLA class I on peripheral T lymphocytes (P < 0.05) and NK cells (P < 0.05) in the high-risk group.

CONCLUSIONSHLA class I on peripheral T lymphocytes and NK cells may be involved in tumorigenesis and development of gastrointestinal tumor, and understanding their changes in expression may provide new insights into the mechanism of tumor immunity.

Adult ; Aged ; Biomarkers, Tumor ; analysis ; Down-Regulation ; Female ; Gastrointestinal Neoplasms ; immunology ; Histocompatibility Antigens Class I ; analysis ; Humans ; Killer Cells, Natural ; immunology ; Male ; Middle Aged ; T-Lymphocytes ; immunology

The regulation mechanism of interferon (IFN) and IFN-stimulated genes is a very complex procedure and is dependent on cell types and virus species. We observed molecular changes related to anti-viral responses in endothelial cells during Hantaan virus (HTNV) infection. We found that there are two patterns of gene expression, the first pattern of gene expression being characterized by early induction and short action, as in that of type I IFNs,' and the other being characterized by delayed induction and long duration, as those of IRF-7, MxA, and TAP-1/2. Even though there are significant differences in their induction folds, we found that all of IFN-alpha/beta , IRF- 3/7, MxA, and TAP-1/2 mRNA expressions reached the peak when the viral replication was most active, which took place 3 days of post infection (d.p.i.). In addition, an interesting phenomenon was observed; only one gene was highly expressed in paired genes such as IFN-alpha/beta??(3/277-folds), IRF-3/7 (2.2/29.4-folds), and TAP- 1/2 (26.2/6.1-folds). Therefore, IFN-beta, IRF-7, and TAP-1 seem to be more important for the anti-viral response in HTNV infection. MxA was increased to 296-folds at 3 d.p.i. and kept continuing 207-folds until 7 d.p.i.. The above results indicate that IFN-beta works for an early anti-viral response, while IRF7, MxA, and TAP-1 work for prolonged anti-viral response in HTNV infection.
ATP-Binding Cassette Transporters/*genetics ; Blotting, Western ; Cells, Cultured ; Endothelial Cells/metabolism/*virology ; GTP-Binding Proteins/*genetics ; *Gene Expression Regulation ; Hantaan virus/*immunology ; Histocompatibility Antigens Class I/analysis ; Humans ; Interferon Regulatory Factor-3/genetics ; Interferon Regulatory Factor-7/*genetics ; Interferons/*genetics ; RNA, Messenger/analysis

CD8-Positive T-Lymphocytes ; immunology ; Embryonic Development ; Female ; Gene Expression Regulation ; HLA Antigens ; genetics ; physiology ; HLA-G Antigens ; Histocompatibility Antigens Class I ; genetics ; physiology ; Humans ; Killer Cells, Natural ; immunology ; Polymorphism, Genetic ; Pregnancy ; Pregnancy Complications ; immunology ; Receptors, Immunologic ; analysis ; Receptors, KIR2DL5 ; Transplantation, Homologous

OBJECTIVETo assess the accuracy and reliability of the nest-PCR-sequence specific primer(SSP) method in HLA-A site genotyping of single blastomeres retrieved from human pre-implantation embryos.

METHODSBy nest PCR on HLA-A exon 2, the success rate of first-round amplification was estimated for single blastomeres. Based on the first-round amplification, the HLA-A genotype of every single blastomeres was analyzed by commercially available PCR-SSP kits.

RESULTSThe amplification of HLA-A exon 2 were performed to 120 blasotmeres retrieved from in vitro fertilization(IVF) surplus embryos donated by 10 couples. The average success rate of family 1-5 and 6-10 was 78.2%(43/55) and 93.8%(61/65), respectively. And 86.7%(104/120) in total. Eighty blastomeres were further tested by nest-PCR-SSP, among which 11 blastomeres failed to HLA-A exon 2 amplification and then failed to genotyping while the other 69 blastomeres succeed in HLA-A exon 2 amplification and succeed in genotyping. Except for 6 blastomeres that were uncertain for allele lost because of parents' homozygosity, the left 63 blastomeres had accurate HLA genotyping. Among these 63 blastomeres, 59 blastomeres had genotypes confirmed from their parents(93.6%), 3 blastomeres lost one of parents' alleles(4.8%), and only one blastomere had two more than parents' alleles(1.6%).

CONCLUSIONThe above research results indicated that based on the successful first round amplification of single blastomeres, nest-PCR-SSP strategy offers a convenient and reliable option for HLA genotyping on single blastomeres, which is a key process in pre-selecting HLA-identical sibling for allogeneic cord blood cell transplantation.

Base Sequence ; Blastomeres ; metabolism ; DNA ; analysis ; DNA Fingerprinting ; methods ; DNA Mutational Analysis ; Female ; HLA Antigens ; analysis ; HLA-A Antigens ; analysis ; genetics ; Histocompatibility Antigens Class I ; analysis ; genetics ; Humans ; Male ; Polymerase Chain Reaction ; methods ; Single Person

OBJECTIVETo investigate the regulatory effect of IFN-gamma on recognition of target cells by human natural killer (NK) cells.

METHODSThe cytotoxic activity of human NK cell lines (NK92, NKL) was detected by MTT method. Expression of NK cell receptors (NKG2D, NKG2A/B, KIR2DL1 and KIR2DS1) and MICA on target cells (the ligand of NKG2D) was measured by RT-PCR.

RESULTSBoth NK92 and NKL cells exerted higher cytotoxicity to tumor cells with MICA expression, while tumors without MICA expression could resist NK cell lysis. IFN-gamma (> 1000 U/ml) inhibited NK lysis of tumor cells with MICA expression through down-regulating the expression of NKG2D, but up-regulating the expression of NKG2A/B and KIR2DL1.

CONCLUSIONIFN-gamma has a negative effect on activation and cytotoxicity of human NK cells by altering the balance between the expression of activating and inhibitory receptors on NK cells in favor of inhibition. This may serve to limit NK cell over-activation in vivo.

Cell Division ; drug effects ; Cytotoxicity, Immunologic ; drug effects ; Histocompatibility Antigens Class I ; analysis ; physiology ; Humans ; Interferon-gamma ; pharmacology ; Killer Cells, Natural ; immunology ; NK Cell Lectin-Like Receptor Subfamily C ; NK Cell Lectin-Like Receptor Subfamily K ; Receptors, Immunologic ; metabolism ; Receptors, KIR2DL1 ; Receptors, Natural Killer Cell ; Recombinant Proteins ; Tumor Cells, Cultured