Novel Association of Killer Cell Immunoglobulin-like Receptor Genes with EBV-infectious Diseases in Children

Killer cell immunoglobulin-like receptors （KIRs） which are mainly expressed on natural killer （NK） cells are implicated in many virus infections. However, it is unclear whether or not KIRs are associated with susceptibility to Epstein-Barr virus （EBV） infection related diseases. Therefore, the purpose of our study was to investigate possible correlation between polymorphisms of KIR genes and infectious mononucleosis （IM）/EBV-associated hemophagocytic Iymphohistiocytosis （EBV-HLH）. The polymorphisms of KIR genes were detected by polymerase chain reaction with sequence-specific primers （PCR-SSP）. The results would contribute to clarify the association of KIRs with EBV induced diseases, and provide new insights into the role of NK cells and innate immune response against viral infections and/or subsequent progression.

Variations in killer-cell immunoglobulin-like receptor and human leukocyte antigen genes and immunity to malaria

Malaria is one of the deadliest infectious diseases in the world. Immune responses to Plasmodium falciparum malaria vary among individuals and between populations. Human genetic variation in immune system genes is likely to play a role in this heterogeneity. Natural killer (NK) cells produce inflammatory cytokines in response to malaria infection, kill intraerythrocytic Plasmodium falciparum parasites by cytolysis, and participate in the initiation and development of adaptive immune responses to plasmodial infection. These functions are modulated by interactions between killer-cell immunoglobulin-like receptors (KIRs) and human leukocyte antigens (HLAs). Therefore, variations in KIR and HLA genes can have a direct impact on NK cell functions. Understanding the role of KIRs and HLAs in immunity to malaria can help to better characterize antimalarial immune responses. In this review, we summarize the different KIRs and HLAs associated with immunity to malaria thus far.

Co-Inhibitors of Second Signal of Lymphocyte Response in Human Renal Transplants: PD-L2, GITR, and ILT-2/3/5 Positive Cells from Aspiration Biopsies Associate with Acute Rejection-Freedom

Following organ transplantation, the outcome of the encounter between an APC and a T lymphocyte is strongly dependent on the presence of costimulatory and co-inhibitory molecules, the former associated with allograft rejection and the latter with allograft acceptance. We evaluated the expression of PD-L2, GITR, ILT-2/3/5, and ILT-4 on graft-infiltrating cells procured by Fnab from human KTx under different immunosuppressive regimens. Methods: Fnab biopsies were performed on days 7 or 14 - 30 in stable KTx and on the day of acute rejection diagnosis. Cytopreparations were studied by the enzymatic avidin biotin complex staining. Results: Acute rejection group showed a significant down-regulated expression of PD-L2, GITR, and ILT-2/3/5 as compared to stable group, while for ILT-4 we did not find significant difference. Anti-IL2αR and rapamicyn treatment trend to down-regulate ILT-4 expression, although meaningless. A significantly positive correlation was observed between PD-L2 and GITR expression in Fnab. The PPV for acute rejection diagnosis for both PD-L2 and GITR was clearly above 0.8. Conclusions: Our findings point to an early entrance of cells expressing PD-L2, GITR and ILT-2/3/5 inside human KTx who are going to remain rejection-free. Both PD-L2 and GITR shared a high ability to rule-in and rule-out acute rejection.

79例广东汉族人群HLA-Cw及其KIR分析

目的:了解HLA-Cw与相应刺激性KIR(杀伤细胞免疫球蛋白样受体)和抑制性KIR在广东汉族人群中的分布。方法:对79例广东汉族骨髓移植供者,以DNA技术检测HLA-Cw和KIR表型。根据对KIR识别的特异性,将HLA-Cw分为HLA-Cwlys、HLA-Cwasn,分析个体HLA-Cw与相应刺激性或抑制性KIR的识别情况。结果:本组人群中,HLA-Cwlys、HLA-Cwasn的频率分别为26.6%、97.5%。表达KIR2DL1而无相应配体者62.0%,表达2DS1而无相应配体者15.1%。27.8%表达HLA-Cwasn而不表达相应KIR。25.3%、55.6%有抑制性HLA-Cwlys或HLA-Cwasn配体受体对,1.3%和14.0%的个体单独表达刺激性HLA-Cwlys或HLA-Cwasn配体受体对。15.1%的个体表达KIR2DS1而不表达HLA-Cwlys。结论:在广东汉族人群中,存在KIR表型与自身HLA表型分离现象。抑制性HLA-Cw-KIR配对表达高于刺激性配对,约1/5单独表达刺激性HLA-Cw-KIR配对。

Immunogenetic characteristics of patients with autoimmune gastritis

AIM:To explore whether predisposition to autoimmune gastritis (AIG) is found in human leukocyte antigen (HLA), cytokine or killer cell immunoglobulin-like receptor (KIR) gene variations.METHODS: Twelve Finnish patients with autoimmunetype severe atrophy of the gastric corpus were included. The patients' serum was analyzed for pepsinogen-interleukin (IL)-1 gene cluster, IL-2, IL-4, IL-6, IL-10, IL-12, interferon γ, transforming growth factor β, and tumor necrosis factor α. Variation in KIR genes was also explored. The results were compared with prevalence of the polymorphisms in Finnish or European populations.RESULTS: All patients had pepsinogen-CONCLUSION: As explored with modern DNA-based methods, HLA-DRB1*04 and DQB1*03 alleles, but not HLA-B8-DRB1*03, may predispose to AIG.

Genetic barriers in transplantation medicine

The successful of transplantation is determined by the shared human leukocyte antigens(HLAs) and ABO blood group antigens between donor and recipient. In recent years, killer cell receptor [i.e., killer cell immunoglobulinlike receptor(KIR)] and major histocompatibility complex(MHC) class I chain-related gene molecule(i.e., MICA) were also reported as important determinants of transplant compatibility. At present, several different genotyping techniques(e.g., sequence specific primer and sequence based typing) can be used to characterize blood group, HLA, MICA and KIR and loci. These molecular techniques have several advantages because they do not depend on the availability of anti-sera, cellular expression and have greater specificity and accuracy compared with the antibody-antigen based typing. Nonetheless, these molecular techniques have limited capability to capture increasing number of markers which have been demonstrated to determine donor and recipient compatibility. It is now possible to genotype multiple markers and to the extent of a complete sequencing of the human genome using next generation sequencer(NGS). This high throughput genotyping platform has been tested for HLA, and it is expected that NGS will be used to simultaneously genotype a large number of clinically relevant transplantation genes in near future. This is not far from reality due to the bioinformatics support given by the immunogenetics community and the rigorous improvement in NGS methodology. In addition, new developments in immune tolerance based therapy, donor recruitment strategies and bioengineering are expected to provide significant advances in the field of transplantation medicine.