Genetic profile of RHCE, Kell, Duffy, Kidd, Diego and MNS hybrid glycophorins blood groups in ethnic northeastern Thais: Alleles, genotypes and risk of alloimmunisation.

BACKGROUND: Antibodies against blood group antigens play a key role in the pathophysiology of haemolytic transfusion reactions (HTRs) and haemolytic disease of the fetus and newborn (HDFN). This study aimed to determine the frequencies of alleles, genotypes, and risk of alloimmunisation of clinically significant blood group systems in ethnic northeastern Thais. METHODS: In total, 345 unrelated, healthy, ethnic northeastern Thais were tested using the in-house PCR-sequence specific primers (PCR-SSP) method for simultaneously genotyping of RHCE, Kell, Duffy, Kidd, Diego and MNS glycophorin hybrids and results confirmed by Sanger sequencing. RESULTS: In this cohort, the alleles RHCE*C (81.0%) and RHCE*e (84.8%) were more prevalent than RHCE*c (19.0%) and RHCE*E (15.2%). The most common predicted haplotype combinations of the RHCE alleles were C+c-E-e+(R1R1) (59.4%) followed by the C+c+E+e+ (R1R2) (20.6%) and C+c+E-e+ (R1r) (11.3%). The KEL*01 allele was not found in this study. The frequencies of FY*01 and FY*02 were 88.3% and 11.7%, respectively. The genotype FY*02/02 was found in four samples (1.2%). The frequencies of JK*01 and JK*02 were 52.5% and 47.5%, respectively. Homozygous JK*02/02 was found in 81 samples (23.5%). The frequencies of DI*01 and DI*02 were 0.6% and 99.4%, respectively. In total, 64 samples (18.6%) were found to carry the MNS glycophorin hybrids. CONCLUSIONS: Our results indicated a possible high risk of c, E, Fyb, Jka, Jkb and Mia alloimmunisation in these populations. Moreover, methods established for genotyping clinically significant blood groups in this study can now be utilised in routine clinical application.

T helper cell responses to Opisthorchis viverrini infection associate with host susceptibility.

Opisthorchis viverrini infection is endemic in the lower Mekong subregion. The liver is an organ that worms are drawn to and cause damage. However, the immune-related susceptibility in the liver is poorly understood. In this study, we investigated T helper (Th) cell responses in the liver of BALB/c mice and golden Syrian hamsters during 2-28 days post-infection (DPI). We found that Th cell responses were distinct between mice and hamsters in terms of dynamics and polarization. Mice exhibited the early induction of Th1, Th2, Th17, and regulatory T (Treg) cells responses after the presence of O. viverrini worms at 2 DPI. In hamsters, the late induction of Th1/Th17, downregulation of Th2/Treg responses and early elevation of suppressive cytokine interleukin (IL)-10 were found together with swift reduction of Th cell numbers. Interestingly, expressions of IL-4 (Th2 functional cytokine) and Foxp3 (Treg lineage) were completely different between mice and hamsters which elevated in mice but suppressed in hamsters. These results suggest that early induction and well-regulation are related to host resistance. In contrast, late induction of Th cell response might allow immature worms to develop in the host. Our findings provide a greater understanding in Th cell response-related susceptibility in O. viverrini infection which would be targeting immunity for the development of immune-based intervention such as vaccine.

RHD 1227 A and hybrid Rhesus box analysis in Thai RhD+ and RhD- blood donors: Prevalence, RHD zygosity, and molecular screening.

BACKGROUND AND OBJECTIVES: DEL (D-elute) red blood cells (RBCs) are typed as D- by routine serological methods, as they carry a very weak form of D variant. Asia type DEL (c.1227 G>A) is the most prevalent DEL allele in East Asian populations that can lead to alloimmunization in D negative transfusion recipients. This study aimed to screen D+ and D- Thai blood donors for the Asia type DEL and its zygosity. MATERIALS AND METHODS: Blood samples of 723 D+ , and 191 D- Thai blood donors were collected. D antigen was typed by the routine serological method and adsorption-elution test to screen DEL phenotype. The hybrid Rhesus box, RHD 1227 G, RHD 1227 A and RHD exon 4 were analyzed with polymerase chain reaction using sequence specific primers, PCR-SSP. RESULTS: Among 191 D- blood donors, 52 (27.2%) RHD 1227 A allele carriers were detected, and 39 out of these 52 (75.0%) were positive for the hybrid Rhesus box (i.e. hemizygous RHD 1227 A). The remaining carriers were RHD 1227 A homozygous. RHD zygosity analysis in Thai D+ blood donors showed that only 4% (29/723) had a Dd genotype (hemizygous RHD 1227 G). Five (0.69%) blood donors were detected with RHD 1227 A alleles among 723 D+ blood donors. They were all G/A heterozygous at the RHD 1227 site. CONCLUSION: This study indicates that the high prevalence of RHD 1227 A allele among serologically apparent D- blood donors in Thais. Furthermore, the screening of hybrid Rhesus box, RHD 1227 A combined with RHD exon 4 is useful for analyses of Asia type DEL and its zygosity.

Telomere Length Is Correlated with Resting Metabolic Rate and Aerobic Capacity in Women: A Cross-Sectional Study.

This study investigated the associations between relative telomere length (RTL) and resting metabolic rate (RMR), resting fat oxidation (RFO), and aerobic capacity and whether oxidative stress and inflammation are the underlying mechanisms in sedentary women. We also aimed to determine whether the correlations depend on age and obesity. Sixty-eight normal weight and 66 obese women participated in this study. After adjustment for age, energy expenditure, energy intake, and education level, the RTL of all participants was negatively correlated with absolute RMR (RMRAB) and serum high-sensitivity C-reactive protein (hsCRP) concentration, and positively correlated with maximum oxygen consumption (V˙O2max) (all p < 0.05). After additional adjustment for adiposity indices and fat-free mass (FFM), RTL was positively correlated with plasma vitamin C concentration (p < 0.05). Furthermore, after adjustment for fasting blood glucose concentration, RTL was negatively correlated with age and positively correlated with V˙O2max (mL/kg FFM/min). We found that normal weight women had longer RTL than obese women (p < 0.001). We suggest that RTL is negatively correlated with RMRAB and positively correlated with aerobic capacity, possibly via antioxidant and anti-inflammatory mechanisms. Furthermore, age and obesity influenced the associations. We provide useful information for the management of promotion strategies for health-related physical fitness in women.

Biosensors Based on Ion-Sensitive Field-Effect Transistors for HLA and MICA Antibody Detection in Kidney Transplantation.

This work demonstrates the ability of the Ion-Sensitive Field-Effect Transistor (ISFET)-based immunosensor to detect antibodies against the human leukocyte antigen (HLA) and the major histocompatibility complex class-I-related chain A (MICA). The sensing membrane of the ISFET devices was modified and functionalized using an APTES-GA strategy. Surface properties, including wettability, surface thickness, and surface topology, were assessed in each module of the modification process. The optimal concentrations of HLA and MICA proteins for the immobilization were 10 and 50 µg/mL. The dose-response curve showed a detection range of 1.98-40 µg/mL for anti-HLA and 5.17-40 µg/mL for anti-MICA. The analytical precision (%CV) was found to be 10.69% and 8.92% for anti-HLA and -MICA, respectively. Moreover, the electrical signal obtained from the irrelevant antibody was considerably different from that of the specific antibodies, indicating the specific binding of the relevant antibodies without noise interference. The sensitivity and specificity in the experimental setting were established for both antibodies (anti-HLA: sensitivity = 80.00%, specificity = 86.36%; anti-MICA: sensitivity = 86.67%, specificity = 88.89%). Our data reveal the potential of applying the ISFET-based immunosensor to the detection of relevant anti-HLA and -MICA antibodies, especially in the field of kidney transplantation.

Prevalence of leucocyte antibodies in non-transfused male and female platelet apheresis donors.

OBJECTIVES: In our study group of Thai PLT apheresis donors, we assessed the prevalence of anti-leucocyte antibodies. BACKGROUND: Antibodies against human leucocyte antigens (anti-HLA), neutrophil antigens (anti-HNA), and major histocompatibility complex class I related chain A (anti-MICA) in blood products can lead to transfusion-related acute lung injury (TRALI). To reduce the risk of TRALI, some blood centres are implementing strategies based on screening platelet (PLT) apheresis donors for the presence of anti-leucocyte antibodies. METHODS/MATERIALS: Blood samples were collected from non-transfused individuals, 340 males and 63 females (50 nulliparous and 13 parous). Anti-HLA class I and II and anti-MICA were analysed using the Luminex assay, and anti-HNA-3 was detected using the granulocyte agglutination test. RESULTS: Anti-HLA was found in 14 of 403 subjects (3.5%). Ten subjects (2.5%) tested positive for HLA class I, 2 (0.5%) for HLA class II, and 2 (0.5%) for both HLA class I and HLA class II. Anti-HLA class I or II were detected in 2 of 13 (15.4%) parous females and only anti-HLA class I was found in 4 (8.0%) nulliparous females. Six of 327 subjects tested (1.8%), all males, were positive for anti-MICA. Anti-HNA-3 was not found in any of the 403 individuals. CONCLUSIONS: Screening for anti-HLA class I and II should be implemented for Thai PLT apheresis donors. Although immunisation against HNA and MICA seems to be a rare event in Thais, further work is necessary to decide whether our PLT apheresis donors should be screened for HNA and MICA antibodies.

Prevalence and impact of HLA and MICA allele mismatching on donor-specific antibodies induction in kidney transplant rejection.

AIM: Donor-recipient antigen mismatching for anti-human leucocyte antigen (HLA) and MICA is one of the risk factors for antibody induction leading to graft rejection. Our aim was to analyze the incidence and specificity of the different DSAs developing and to investigate the impact of HLA and MICA allele mismatches on antibody production in kidney transplant patients experiencing antibody-mediated rejection (AMR). METHODS: We retrospectively reviewed 253 consecutive recipients of kidney transplant who were diagnosed as experiencing AMR. RESULTS: Our results showed that around 27% of our patients were positive for DSAs over a median follow-up period of 24 months. Antibody to HLA-DQ7 was the most prevalent DSA detected. The allele mismatch number was significantly lower for DQ loci than -A and -B loci (DQ vs. A, p < .001; DQ vs. B, p = .002). Considering each HLA antigen, the incidence rate of DQ-DSA [41.9 (32.92-51.46; 95%CI)] was much higher than the rate observed for DSA directed to -A, -DR and -B loci. Half of the recipients in the DQ-DSA-only group, and the DQ-DSA together with non-DQ group, had MFI > 5000. Only one case developed de novo MICA-DSA (MICA002). CONCLUSION: Our study indicates that mismatching for HLA and MICA alleles leads to the development of HLA and MICA antibodies in some kidney transplant recipients. We have also demonstrated that DSA to the DQ locus is the most prevalent in kidney transplant patients with AMR. Thus, matching the DQ locus in kidney allocation algorithms may reduce post-transplant development of DSA.

Vitamin C supplementation improves blood pressure and oxidative stress after acute exercise in patients with poorly controlled type 2 diabetes mellitus: A randomized, placebo-controlled, cross-over study.

This study aimed to assess the effect of Vitamin C on blood pressure (BP), and subsequently on oxidative stress and nitric oxide (NO) release, following the low-intensity exercise in the patients. This study included 24 patients with type 2 diabetes mellitus (T2D) (age, 53 ± 7 years; hemoglobin A1c, 10.1% ± 0.9%) randomized into two 6-week daily arms based on the consumption of either placebo or 1000 mg Vitamin C. The crossover trial occurred after a 6-week washout. Before and after both supplementation arms, all patients performed cycling exercise at 33% of peak oxygen consumption for 20 min. BP was measured before, immediately, and 60 min after the exercise. Blood samples were drawn immediately before and after the exercise to determine plasma ascorbate, malondialdehyde (MDA), F2-isoprostanes (F2-IsoPs), and NO concentrations. Data showed significant lower BP in the Vitamin C arm when compared with the placebo arm (systolic BP [SBP] P < 0.001 at every time point, diastolic BP [DBP] P < 0.001 except at immediately after exercise, P < 0.05). Plasma ascorbate concentration (P < 0.05 at every time point) and plasma NO (at resting P < 0.001, immediately after exercise P < 0.05) were significantly increased in the Vitamin C arm than in the placebo arm. Plasma MDA (P < 0.05 at every time point) and F2-IsoPs (P < 0.05 at every time point) concentrations were significantly lower in the Vitamin C arm than in the placebo arm. In addition, data showed significantly lower SBP (P < 0.001 at every time point), DBP (P < 0.001 except at immediately after exercise P < 0.05), plasma MDA (P < 0.001 at every time point), and F2-IsoPs (P < 0.05 at every time point) at post-supplementation than at pre-supplementation. Besides, there were significantly higher plasma ascorbate (P < 0.05 at every time point) and NO (at rest P < 0.01, immediately after exercise P < 0.05) concentrations at post-supplementation than at pre-supplementation. This is in contrast to the placebo treatment arm which demonstrated no statistical difference in all outcomes throughout the experiment. This study suggests that 6-week Vitamin C supplementation decreased preexercise and postexercise BPs, possibly due to improved oxidative stress and NO release. However, exercise had no effect on any outcome measures.

Oral Administration of Melatonin or Succinyl Melatonin Niosome Gel Benefits 5-FU-Induced Small Intestinal Mucositis Treatment in Mice.

Mucositis is one of the most adverse effects of 5-fluorouracil (5-FU) and had no standard drug for treatment. Melatonin is a neurohormone, and can ameliorate radiotherapy-induced small intestinal mucositis. Melatonin encapsulated in niosomes improved its poor bioavailability. Succinyl melatonin, a melatonin derivative, showed prolonged release compared with melatonin. This study investigated the efficacy of melatonin niosome gel (MNG) and succinyl melatonin niosome gel (SNG) in 5-FU-induced small intestinal mucositis treatment in mice. MNG and SNG with particle sizes of 293 and 270 nm were shown to have mucoadhesive potentials. The effect of a daily oral application of MNG, SNG, or fluocinolone acetonide gel (FAG, positive control) was compared to that of the normal group. The body weight, food consumption, histology, Fourier transform infrared (FTIR) spectroscopy, inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-1ß), and malondialdehyde (MDA) in the small intestine were monitored. The results showed decreased %body weight and food consumption in all 5-FU-injected groups compared with the normal group. The MNG and SNG treatments maintained the food consumption and the normal integrity of the small intestines, as evidenced by villus length and crypt depth, similar to the observations in the normal groups. The FTIR spectra showed no change in lipids of the MNG and SNG groups compared with the normal group. Moreover, SNG could reduce IL-1ß content to a level that was not different from the level in the normal groups. Therefore, the oral application of MNG and SNG could protect against 5-FU-induced small intestinal mucositis in mice.

Influence of Gold Nanoparticles with Different Surface Charges on Localization and Monocyte Behavior.

The use of gold nanoparticles (AuNP) has been established in nanocarriers, diagnostics, and biosensors. Access to the targeted sites of these nanomaterials could directly involve the first line of defense, the innate immune system. Charges of nanomaterials play a critical role in a number of aspects such as stabilization, cellular uptake, modulation, and function of cells. Interactions and modulations of the charged nanomaterials against the innate immune system may occur even at very low concentration. To understand the effects of charges on monocyte behavior, in this study, the positively and negatively charged AuNP (AuNP+ve and AuNP-ve) of the similar size and shape on cytotoxicity, recognition, cellular behavior, and function were evaluated in vitro using U937 human monocyte cells as an innate immunity model. Both types of AuNP at various concentrations (0-5 nM) exhibited low toxicity. In addition, the cellular internalization of the AuNP+ve and AuNP-ve, as determined by TEM, occurred by different mechanisms, and the internalization had no effect on cellular destruction, as implied by the low levels of %LDH. Interestingly, the AuNP+ve recognition and internalization seemingly entered cells through receptor dependence and strongly affected cellular response to express both pro-inflammatory (IL-1ß) and anti-inflammatory (TGF-ß) cytokines, while the AuNP-ve stimulated TNF-α expression. Nevertheless, the AuNP-treated cells maintained normal function when exposed to planktonic bacteria. Thus, these results indicated that one part of the immune system interacted with different surface-charged AuNP, suggesting appropiate immunomodulation in biomedicine.

Frequency of CD36 deficiency in Thais analyzed by quantification of CD36 on cell surfaces and in plasma.

BACKGROUND: Anti-CD36s, developing after transfusion or during pregnancy, play an important role in immune-mediated bleeding disorders among Asian populations. Currently, little is known about the clinical relevance of anti-CD36. Here, we aimed to determine the frequency of CD36 deficiency in Thais by analyzing CD36 expression on cell surfaces and in plasma. STUDY DESIGN AND METHODS: The expression and deficiency of CD36 on platelets and monocytes were determined by flow cytometry. Mutations in the CD36 gene were analyzed by nucleotide sequencing. Soluble CD36 (sCD36) in plasma was quantified with enzyme-linked immunosorbent assay. RESULTS: Fifteen of 700 blood donors (2.14%) were identified as CD36 deficient. The frequencies of Type I and II CD36 deficiency were 0.43% and 1.71%, respectively. Type I individuals exhibited c.1163A > T, c.429 + 4insG, and c.1156C > T. Type II individuals exhibited c.879 T > C, c.329-330delAC, c.818 + 108delAACT, c.1125 + 13C > A, and c.1163A > T. CD36 on donor platelets (n = 685) showed a wide distribution of expression levels (mean fluorescence intensity, 16.71 ± 8.68). In the normal phenotype (n = 14), sCD36 concentration was 58.84 ± 11.68 ng/mL, which was significantly correlated with platelet CD36 expression (r2 = 0.8551). In Type II-deficient individuals (n = 6), a similar sCD36 concentration was detected (53.67 ± 8.17 ng/mL). However, sCD36 could not be detected in Type I individuals (n = 3). CONCLUSION: CD36 Type I deficiency was found, indicating the potential for immune-mediated platelet disorders in Thais. However, the underlying mutations differed from those reported in Japan and China. Interestingly, sCD36 could not be detected in plasma of Type I-deficient individuals. This finding may lead to the use of plasma to identify individuals at risk and to allow screening of large cohorts.

The effect of KIR and HLA polymorphisms on dengue infection and disease severity in northeastern Thais.

Killer cell immunoglobulin-like receptors (KIRs) are cell surface receptors on natural killer (NK) cells and subsets of T cells. The interaction between KIRs and their cognate ligands (Human leukocyte antigen class I molecules, HLA class I) modulates the immune response of NK cells, in particular through clearance of virus-infected cells. Here, we investigated the effect of KIRs and HLA ligands on dengue infections and disease severity. The KIRs and HLA ligands were identified in 235 healthy controls (HC) and 253 dengue patients (DEN) using polymerase chain reaction with sequence specific primer (PCR-SSP); moreover, DEN was classified to 100 dengue fever (DF) and 153 dengue haemorrhagic fever (DHF). Risks were expressed as odds ratios (ORs) and 95% confidence intervals (CIs) with significance set at a two-tailed P value of < 0.05. The Bonferroni correction was applied for multiple comparisons. Twelve significant associations were observed in dengue infections and disease severity; however, two outcomes survived after the Bonferroni correction. Of these, HLA-A11 was associated with an increased risk to develop dengue disease (OR 2.41, 95% CI 1.62-3.60, Pc = 0.004), while KIR3DS1+ Bw4 was a protective genotype to developing DHF (OR 0.28, 95% CI 0.16-0.48, Pc < 0.001). This study revealed an important role of KIR and HLA ligands in innate immune responses to dengue viral infections and, in particular, their effect on clinical outcomes and disease severity.

The cationic cell-penetrating KT2 peptide promotes cell membrane defects and apoptosis with autophagy inhibition in human HCT 116 colon cancer cells.

The anticancer activity of cationic antimicrobial peptides (AMPs) has become more interesting because some AMPs have selective recognition against cancer cells. However, their antitumor properties and underlying mechanisms in cancer cells have not been clearly understood. In this study, we evaluated the effects of KT2 (lysine/tryptophan-rich AMP) on the cellular uptake and internalization mechanism, cell viability, surface charge of the cell membrane, membrane integrity, apoptotic cell death, and autophagy in human HCT 116 colon cancer cells. We found that KT2 interacted with the cell membrane of HCT 116 cells and was internalized into HCT 116 cells via clathrin-mediated and caveolae-mediated endocytosis mechanisms. The interaction of KT2 with cells caused cell membrane structure change, elevated membrane permeability, and KT2 also affected the lipid component. The results of atomic force microscopy showed cellular membrane defects of KT2-treated cells. The internalized KT2 induced nuclear condensation and apoptotic cell death. It elevated the apoptotic factor levels including those of cytochrome c and apoptosis-inducing factor. Furthermore, KT2 inhibited autophagy by the suppression of autophagy-related 5, autophagy-related 7, autophagy-related 16 like 1, and Beclin-1 proteins. In conclusion, these results revealed the cytotoxicity of cationic KT2 against HCT 116 cells and may help to clarify the interactions between cationic AMPs and cancer cells.

Novel KIR genotypes and gene copy number variations in northeastern Thais.

KIR (Killer Immunoglobulin-like Receptor) variants influence immune responses and are genetic factors in disease susceptibility. Using sequence-specific priming PCR, we have previously described the diversity of KIR genes in term of presence/absence in northeastern Thais (NETs). To provide additional resolution beyond conventional methods, quantitative PCR was applied to determine KIR copy number profiles. Novel expanded and contracted KIR copy number profiles were identified at cumulatively high frequencies. These all comprise haplotypes with duplication (6·9%) or deletion (2·7%) of KIR3DL1/S1 along with adjacent genes. Five expanded KIR profiles comprised haplotypes with duplications of KIR2DP1, 2DL1, 3DP1, 2DL4, 3DL1/S1 and 2DS1/4, whereas two contracted profiles contained only a single copy of KIR3DP1, 3DL1/S1 and 2DL4. Using a KIR haplotype prediction program (KIR Haplotype Identifier), 14% of NET haplotypes carried atypical haplotypes based on the gene copy number data.

Expression and function of the major histocompatibility complex (MHC) class I chain-related A (MICA)*010 in NK cell killing activity.

The major histocompatibility complex (MHC) class I chain-related A (MICA) plays an important role in stress cell recognition. High polymorphisms of MICA are relevant to NKG2D binding capacity, responses of NK cells and tumor progression. In this study, MICA genotyping of 97 cholangiocarcinoma patients was performed using PCR-SSP. MICA*010 was positively associated with a corrected p-value of < 0.001 (RR=2.16 (95 % CI, 1.48-3.14)). MICA*010 was previously reported as a non-expressed allele. Thus, the expression of MICA*010 on the cell surface was studied on both MICA*010 transfected cells (HEK 293 T and L929 cells) and stimulated primary monocytes obtained from homozygous MICA*010 individuals using different clones of antibodies (1H10, 1D10, 1C3.1, 1C3.2, 6D4 and 3H5) for detection. Surprisingly, the expression of MICA*010 could be observed on both transfected cells and stimulated monocytes and effectively bound to the NKG2D-Fc fusion protein. The functional study of various MICA alleles revealed the high relative killing activity of NK cells induced by the MICA*010 transfected C1R cells, not following the previously reported rule of the M129V substitution. The structural analysis highlighted the amino acid at position 36 as another important amino acid relevant to preserving the structural integrity of the MICA protein and NKG2D binding. Our data propose a new aspect of functional MICA contributing motifs and that MICA*010 has a potential effect on NK cell functions and might be applicable to other fields of immune responses.

Polymorphisms of killer immunoglobulin-like receptors (KIRs) and HLA ligands in northeastern Thais.

Killer cell immunoglobulin-like receptors (KIRs) are cell surface receptors on natural killer (NK) cells and subsets of T cells. The functions of NK cells are partly regulated by interactions between KIRs and HLA ligands on target cells. In this study, the presence or absence of 17 KIR genes and their known HLA ligands have been investigated in 235 unrelated individuals living in northeastern Thailand (NET). Subtypes of KIR2DS4 including full length (KIR2DS4F) and deleted forms (KIR2DS4D) have also been determined. Framework genes (KIR2DL4, 3DL2, 3DL3, and 3DP1) were found in all individuals and KIR genes belonging to the A haplotype (KIR2DL1, 2DL3, 3DL1, and 2DS4) were present in more than 90% of NET. KIR2DS4D (61.7%) was more common than KIR2DS4F (52.8%). A total of 33 different KIR genotypes were observed. Of these, three new genotypes were identified. The most common genotype (AA) was observed in 35.7% of NET, and HLA-C alleles bearing the C1 epitope (HLA-C1) had the highest frequency (97%). All individuals had at least one inhibitory KIR and its corresponding HLA ligand; 40.9% of NET had three pairs of receptor-ligand combinations, and 18.3% had all three receptor-ligand combinations of KIR2DL3+C1, 3DL1+Bw4, and 3DL2+A11. Surprisingly, the patterns of KIR gene frequencies in NET are more similar to those of Caucasians than Japanese, Korean, and Chinese. This is the first report on complete analysis of KIR and known HLA ligands in Thais. These data provide basic knowledge on KIR for further studies on disease associations and transplantation in northeastern Thais.

Precursor miR-886, a novel noncoding RNA repressed in cancer, associates with PKR and modulates its activity.

Noncoding RNAs have drawn significant attention in biology recently. Whereas the current research is highly inclined to microRNAs, research on other noncoding RNAs has lagged behind. Here, we investigated a novel noncoding RNA that has been known as precursor microRNA miR-886 (pre-miR-886). Pre-miR-886 has been proposed also as a vault RNA, a component of the vault complex implicated in cancer drug resistance. We identified pre-miR-886 as a 102-nucleotide-long, abundant cytoplasmic RNA that is neither a genuine pre-microRNA nor a vault RNA. Pre-miR-886 is physically associated with PKR (Protein Kinase RNA-activated), an interferon-inducible and double-stranded RNA dependent kinase. The suppression of pre-miR-886 activates PKR and its downstream pathways, eIF2α phosphorylation and the NF-κB pathway, leading to impaired cell proliferation. We also found that pre-miR-886 is suppressed in a wide-range of cancer cell lines and in clinical specimens. This study is the first intense characterization of pre-miR-886 as well as the initial report on its function as a PKR regulator, which suggests a critical role in tumorigenesis.

Association of MICA Gene Polymorphism in Opisthorchis viverrini-Induced Periductal Fibrosis in Northeastern Thais.

OBJECTIVE: Chronic Opisthorchis viverrini (OV) infection is the cause of advanced periductal fibrosis (APF), subsequently leading to cholangiocarcinoma (CCA). Natural killer (NK) cells can kill hepatic stellate cells (HSCs), the initiating cells for fibrosis formation, by using the interaction between the natural killer group 2 member D (NKG2D) receptor and its ligand on the HSCs. This can inhibit the fibrosis formation. Major histocompatibility complex class I chain-related A (MICA) is the ligand of the NKG2D receptor and has highly polymorphic characteristics that are involved in NKG2D binding and NK cell activation. This study aimed to investigate the polymorphism of MICA in OV-induced fibrosis. METHOD: MICA typing was performed by polymerase chain reaction- sequence specific primer (PCR-SSP) and sequencing in two groups: OV infection without fibrosis (N = 99) and with fibrosis (N = 290). RESULT: Six alleles were identified and the MICA*010 allele had the highest frequency in both groups. The MICA*00201-02 allele was a protective factor for fibrosis (OR= 0.508, 95%CI= 0.34-0.76, Pc <0.05), while the MICA*019 allele was suggested to be a risk allele for fibrosis (OR=1.95, 95%CI=1.25-3.03, Pc<0.005). In addition, two motifs, glycine (G) at position 14 and glutamine (Q) at position 251, were negatively associated with fibrosis (G14: OR=0.508, 95%CI=0.34-0.76, Pc <0.05 and Q251: OR=0.586, 95%CI=0.41-0.84, Pc <0.05). Moreover, the distribution of the MICA-129 genotype also showed the protective genotype (Pc<0.05, OR=0.319, 95%CI= 0.12-0.54) for fibrosis. The MICA*00201-02 allele encoded all these motifs, and this suggested that it might lead to strong NK cell activation to kill HSCs, subsequently preventing fibrosis formation. CONCLUSION: This study described initial evidence suggesting that the polymorphism of the MICA gene might be a marker for OV-derived periductal fibrosis.

Improved binding activity of antibodies against major histocompatibility complex class I chain-related gene A by phage display technology for cancer-targeted therapy.

Major histocompatibility complex class I chain-related gene A (MICA) is an NKG2D ligand that is over-expressed under cellular stress including cancer transformation and viral infection. High expression of MICA in cancer tissues or patients' sera is useful for prognostic or follow-up markers in cancer patients. In this study, phage display technology was employed to improve antigen-binding activities of anti-MICA monoclonal antibodies (WW2G8, WW6B7, and WW9B8). The 12 amino acid residues in the complementarity determining regions (CDRs) on the V domain of the heavy chain CDR3 (HCDR3) of these anti-MICA antibodies were modified by PCR-random mutagenesis, and phages displaying mutated anti-MICA Fab were constructed. After seven rounds of panning, five clones of phages displaying mutant anti-MICA Fab which exhibited 3-7-folds higher antigen-binding activities were isolated. Two clones of the mutants (phage-displayed mutant Fab WW9B8.1 and phage-displayed mutant Fab WW9B8.21) were confirmed to have antigen-binding specificity for cell surface MICA proteins by flow cytometry. These phage clones are able to recognize MICA in a native form according to positive results obtained by indirect ELISA and flow cytometry. Thus, these phage particles could be potentially used for further development of nanomedicine specifically targeting cancer cells expressing MICA proteins.

Investigation of trefoil factor expression in saliva and oral mucosal tissues of patients with oral squamous cell carcinoma.

OBJECTIVES: The aims of our study were to determine levels of trefoil factor (TFF) peptides in saliva and oral mucosal tissues from patients with oral squamous cell carcinoma (OSCC), and to evaluate whether individual members of TFFs (TFF1, TFF2, and TFF3) might act as biomarkers of disease. MATERIALS AND METHODS: Saliva samples were from 23 healthy subjects and 23 OSCC patients. Tissue samples were collected from 32 normal oral mucosa (NOM) and 32 OSCC biopsy specimens. ELISA and immunohistochemical methods were used to evaluate the expression of TFF1, TFF2, and TFF3 in saliva and oral mucosal tissues, respectively. RESULTS: Expression of TFF2 and TFF3 in oral mucosal tissues of OSCC patients was strongly downregulated when compared to healthy subjects (p < 0.001 and p = 0.002, respectively). However, there were no differences in levels of salivary TFF concentrations between OSCC patients and healthy subjects. CONCLUSIONS: The present study extends previous observations, demonstrating the reduction of TFF2 and TFF3 expression in oral mucosal tissues of OSCC patients. CLINICAL RELEVANCE: These findings suggest the clinical significance of TFF2 and TFF3 molecules as negative markers of tumor progression in OSCC. Quantification of TFF levels in saliva may not be optimal in terms of diagnostic or predictive value for OSCC derived from oral mucosa.