CCR6/CCR10-mediated plasmacytoid dendritic cell recruitment to inflamed epithelia after instruction in lymphoid tissues

Absent in peripheral tissues during homeostasis, human plasmacytoid dendritic cells (pDCs) are described in inflamed skin or mucosa. Here, we report that, unlike blood pDCs, a subset of tonsil pDCs express functional CCR6 and CCR10, and their respective ligands CCL20 and CCL27are detected in inflamed epithelia contacting blood dendritic cell antigen 2(+) pDCs. Moreover, pDCs are recruited to imiquimod-treated skin tumors in WT but not CCR6-deficient mice, and competitive adoptive transfers reveal that CCR6-deficient pDCs are impaired in homing to inflamed skin tumors after intravenous transfer. On IL-3 culture, CCR6 and CCR10 expression is induced on human blood pDCs that become responsive to CCL20 and CCL27/CCL28, respectively. Interestingly, unlike myeloid DC, blood pDCs initially up-regulate CCR7 expression and CCL19 responsiveness on IL-3 ± CpG-B and then acquire functional CCR6 and CCR10. Finally, IL-3-differentiated CCR6(+) CCR10(+) pDCs secrete high levels of IFN-α in response to virus. Overall, we propose an unexpected pDCs migratory model that may best apply for mucosal-associated lymphoid tissues. After CCR7-mediated extravasation into lymphoid tissues draining inflamed epithelia, blood pDCs may be instructed to up-regulate CCR6 and/or CCR10 allowing their homing into inflamed epithelia (in mucosae or skin). At this site, pDCs can then produce IFN-α contributing to pathogen clearance and/or local inflammation.     

Different inactivating mutations in the LU genes of three individuals with the Lutheran-null phenotype

BACKGROUND: The null phenotype of the Lutheran blood group system, Lu(null) or Lu(a-b-), is characterized by the lack of all Lutheran system antigens. It can arise from three genetic backgrounds: recessive, dominant, or X-linked. Lu(null) of the recessive type appears to result from homozygosity for an inactive LU gene. STUDY DESIGN AND METHODS: Three unrelated recessive Lu(null) individuals were assessed by standard serologic tests. All exons of the LU gene were directly sequenced from amplified genomic DNA. The validity of the observed mutations within the LU gene was confirmed by the use of either restriction enzymes or allele-specific primers. RESULTS: All three individuals had the serologic characteristics of recessive Lu(null). One individual was doubly heterozygous for a nonsense mutation 691C>T in exon 6 (Arg231STOP) and a deletion of LU exons 3 and 4. The other two samples showed homozygous nonsense mutations: one had 711C>A in exon 6 (Cys237STOP) and the other 361C>T in exon 3 (Arg121STOP). CONCLUSIONS: The results revealed four unique genetic backgrounds from three examples of the rare recessive Lu(null) phenotype, each encoding Lutheran glycoproteins with a disrupted structure.     

Identification and quantification of isoguanosine in humans and mice

Isoguanine (2-hydroxyadenine), considered to be a non-natural nucleobase has, however, been shown to occur in the croton bean, butterfly wings and a mollusk. For the first time, to the best of our knowledge, we report the identification of isoguanosine (2-hydroxyadenosine), the ribonucleoside, in humans and mouse. Isoguanosine is identified and quantified in RNA from mouse liver samples and in human urine and cerebrospinal fluid. Isoguanine could not be detected as the 2′-deoxyribonucleoside in mouse liver DNA. It could be speculated that the source of isoguanosine was formation from adenosine during oxidative stress in the body. However, the urinary concentrations of isoguanosine and the levels in the liver found here by using isotope dilution liquid chromatography–tandem mass spectrometry are identical to or exceed those of 8-oxo-7,8-dihydro-2′-deoxyguanosine and 8-oxo-7,8-dihydro-guanosine. Guanine is the nucleobase that is oxidized the easiest, so it appears spectacular that the levels of isoguanosine are higher than the levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine and 8-oxo-7,8-dihydro-guanosine. It also appears intriguing that it was only possible to detect the ribonucleoside isoguanosine and not the 2′-deoxyribonucleoside. These observations could indicate that the isoguanosine found is not formed by oxidative stress and could have biological functions.     

Mapping Electrical Impedance Spectra of the Healthy Oral Mucosa: a Pilot Study

Objective

Electrical impedance is the resistance to the electric current flow through a tissue and depends on the tissue’s structure and chemical composition. The aim of this study was to map electrical impedance spectra for each region of the healthy oral mucosa.

Materials and Methods

Electrical impedance was measured in 30 participants with healthy oral mucosa. Measurements were performed in 14 points on the right and the left side of the oral cavity, and repeated after 7 and 14 days respectively.

Results

The lowest values were measured on the tongue dorsum and the highest values were measured on the hard palate. No significant differences were found between the right and the left side. Significantly higher values were found in females on the upper labial mucosa, tongue dorsum and the ventral tongue. Significant difference between smokers and non-smokers on the lower labial mucosa and floor of the mouth was found. Electrical impedance was negatively correlated with salivary flow on the upper labial mucosa, hard palate, tongue dorsum and sublingual mucosa. Higher variability of measurements was found at low frequencies.

Conclusions

Electrical impedance mostly depends on the degree of mucosal keratinization. Demographic and clinical factors probably affect its values. Further studies with bigger number of participants are required.Key words: Electrical impedance, electrical impedance spectrum measurement, healthy oral mucosa     

CD151, the first member of the tetraspanin (TM4) superfamily detected on erythrocytes, is essential for the correct assembly of human basement membranes in kidney and skin

Tetraspanins are thought to facilitate the formation of multiprotein complexes at cell surfaces, but evidence illuminating the biologic importance of this role is sparse. Tetraspanin CD151 forms very stable laminin-binding complexes with integrins alpha3beta1 and alpha6beta1 in kidney and alpha3beta1 and alpha6beta4 in skin. It is encoded by a gene at the same position on chromosome 11p15.5 as the MER2 blood group gene. We show that CD151 expresses the MER2 blood group antigen and is located on erythrocytes. We examined CD151 in 3 MER2-negative patients (2 are sibs) of Indian Jewish origin with end-stage kidney disease. In addition to hereditary nephritis the sibs have sensorineural deafness, pretibial epidermolysis bullosa, and beta-thalassemia minor. The 3 patients are homozygous for a single nucleotide insertion (G383) in exon 5 of CD151, causing a frameshift and premature stop signal at codon 140. The resultant truncated protein would lack its integrin-binding domain. We conclude that CD151 is essential for the proper assembly of the glomerular and tubular basement membrane in kidney, has functional significance in the skin, is probably a component of the inner ear, and could play a role in erythropoiesis.     

Dopamine agonists prevent duodenal ulcer relapse

The present study investigated both the healing rate (after four weeks) and the relapse rate (during six months) following treatment with the dopamine-like drugs bromocriptine (2.5 mg twice daily), amantadine (100 mg nocte), or with the H₂ blockers cimetidine (800 mg nocte), and famotidine (40 mg nocte) in 124 patients with endoscopically proven duodenal ulcer (DU). The ulcer was completely healed in 27 (amantadine), 26 (bromocriptine), 23 (cimetidine), and in 24 (famotidine) patients. Relapse was noted in 34.7% (cimetidine) and 25% (famotidine) versus 11.7% (amantadine) and 7.7% (bromocriptine) DU patients. No significant difference was found in initial healing rates. However, the relapse rate in the cimetidine-treated group was significantly higher than in all the other test groups. Additional comparisons between all the treatment categories showed a significantly lower relapse rate with the dopamine-like agents. These important new results indicate that dopamine-like compounds are equally effective as H₂ blockers in inducing DU healing and may offer a promising advantage over H₂ blockers concerning their efficacy in preventing ulcer relapse in DU patients.     

A KEL gene encoding serine at position 193 of the Kell glycoprotein results in expression of KEL1 antigen

BACKGROUND: The KEL2/KEL1 (k/K) blood group polymorphism represents 578C>T in the KEL gene and Thr193Met in the Kell glycoprotein. Anti-KEL1 can cause severe hemolytic disease of the fetus and newborn. Molecular genotyping for KEL*1 is routinely used for assessing whether a fetus is at risk. Red blood cells (RBCs) from a KEL:1 blood donor (D1) were found to have abnormal KEL1 expression during evaluation of anti-KEL1 reagents. STUDY DESIGN AND METHODS: Kell genotyping methods, including KEL exon 6 direct sequencing, were applied. KEL cDNA from D1 was sequenced. Flow cytometry was used to assess KEL1 and KEL2 RBC expression. RESULTS: RBCs from the donor, her mother, and an unrelated donor gave weak or negative reactions with some anti-KEL1 reagents. Other Kell-system antigens appeared normal. The three individuals were homozygous for KEL C578 (KEL*2) but heterozygous for a 577A>T transversion, encoding Ser193. They appeared to be KEL*2 homozygotes by routine genotyping methods. Flow cytometry revealed weak KEL1 expression and normal KEL2, similar to that of KEL*2 homozygotes. CONCLUSION: Ser193 in the Kell glycoprotein appears to result in expression of abnormal KEL1, in addition to KEL2. The mutation is not detected by routine Kell genotyping methods and, because of unpredicted KEL1 expression, could lead to a misdiagnosis.     

The hematopoietic cell transplantation comorbidity index is a predictor of early death and survival in adult acute myeloid leukemia patients

The hematopoietic cell transplantation comorbidity index (HCT-CI) is predictive of early death and survival in elderly patients with acute myeloid leukemia (AML). The aim of this study was to determine the prognostic role of the HCT-CI for early death and survival in adult AML patients. In the single-center retrospective study, we analyzed the outcome of 233 adult AML patients. The results indicated that the HCT-CI score is an independent predictor of early death in entire cohort of adult patients with AML. In subgroup analysis, HCT-CI is an independent predictor for early death in elderly patients but not in patients younger than 60 years. A high HCT-CI score predicts shorter survival in adult patients with AML.