Alpha E beta 7 (CD103) expression identifies a highly active, tonsil-resident effector-memory CTL population

The characterization of antiviral CTL responses has largely been limited to assessing Ag-specific immune responses in the peripheral blood. Consequently, there is an incomplete understanding of the cellular immune responses at mucosal sites where many viruses enter and initially replicate and how the Ag specificity and activation status of CTL derived from these mucosal sites may differ from that of blood-derived CTL. In this study, we show that EBV-specific CTL responses in the tonsils are of comparable specificity and breadth but of a significantly higher magnitude compared with responses in the peripheral blood. EBV-specific, tonsil-resident, but not PBMC-derived, T cells expressed the integrin/activation marker CD103 (alphaEbeta7), consistent with the detection of its ligand, E-cadherin, on tonsillar squamous cells. These CD8-positive, CD103-positive, tonsil-derived CTL were largely CCR7- and CD45RA- negative effector-memory cells and responded to lower Ag concentrations in in vitro assays than their CD103-negative PBMC-derived counterparts. Thus, EBV-specific CTL in the tonsil, a crucial site for EBV entry and replication, are of greater magnitude and phenotypically distinct from CTL in the peripheral blood and may be important for effective control of this orally transmitted virus.     

Adamantyl triazoles as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1

Adamantyl triazoles were identified as selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). They are active both in in vitro and in in vivo pharmacodynamic models. The synthesis and structure-activity relationships of these inhibitors are presented.     

Transformation of hematopoietic cell lines to growth-factor independence and induction of a fatal myelo- and lymphoproliferative disease in mice by retrovirally transduced TEL/JAK2 fusion genes.

Recent reports have demonstrated fusion of the TEL gene on 12p13 to the JAK2 gene on 9p24 in human leukemias. Three variants have been identified that fuse the TEL pointed (PNT) domain to (i) the JAK2 JH1-kinase domain, (ii) part of and (iii) all of the JH2 pseudokinase domain. We report that all of the human TEL/JAK2 variants, and a human/mouse chimeric hTEL/mJAK2(JH1) fusion gene, transform the interleukin-3 (IL-3)-dependent murine hematopoietic cell line Ba/F3 to IL-3-independent growth. Transformation requires both the TEL PNT domain and JAK2 kinase activity. Furthermore, all TEL/JAK2 variants strongly activated STAT 5 by phosphotyrosine Western blots and by electrophoretic mobility shift assays (EMSA). Mice (n = 40) transplanted with bone marrow infected with the MSCV retrovirus containing either the hTEL/mJAK2(JH1) fusion or its human counterpart developed a fatal mixed myeloproliferative and T-cell lymphoproliferative disorder with a latency of 2-10 weeks. In contrast, mice transplanted with a TEL/JAK2 mutant lacking the TEL PNT domain (n = 10) or a kinase-inactive TEL/JAK2(JH1) mutant (n = 10) did not develop the disease. We conclude that all human TEL/JAK2 fusion variants are oncoproteins in vitro that strongly activate STAT 5, and cause lethal myelo- and lymphoproliferative syndromes in murine bone marrow transplant models of leukemia.     

Community Health Seeking Behavior for Suspected Human and Animal Rabies Cases,Gomma District,Southwest Ethiopia

Background

Timely presentation to appropriate health service provider of sick animals/humans from zoonotic diseases like rabies is important for early case/outbreak detection and management. However, data on community’s health seeking practice for rabies in Ethiopia is limited. Therefore the objective of this study was to determine community’s health seeking behavior on rabies, Southwest Ethiopia.

Methods

A cross-sectional survey was conducted from January 16-February 14, 2015 to collect data from 808 respondents where the respondents were selected using multistage sampling technique. Data were collected using interviewer administered structured questionnaire by trained epidemiology graduate level students. Data were entered to Epidata version 3.1 and analyzed using SPSS version 20 for windows.

Result

Eight hundred three (99.4%) respondents participated in the study. Out of 28 respondents who reported their family members’ exposure to rabies, 8 of them replied that the exposed family members sought treatment from traditional healers. More than nine in ten respondents perceived that humans and domestic animals with rabies exposure should seek help of which 85% of them suggested modern health care facilities as the preferred management option for the sick humans and domestic animals. However, among those who reported sick domestic animals, near to 72% of them had either slaughtered for human consumption, sold immediately, visited traditional healer, given home care or did nothing for the sick domestic animals.

Conclusion

Majority of the respondents had favorable perception of seeking treatment from modern health care facilities for rabies. However, significant number of them had managed inappropriately for the sick domestic animals from rabies. Hence, raising awareness of the community about management of sick domestic animals from rabies and the need for reporting to both human and animal health service providers is needed.     

Genetic diversity and differentiation of cultivated amochi (Arisaema schimperianum Schott) in Ethiopia as revealed by AFLP markers

Amochi (Arisaema schimperianum Schott) is an off-season crop plant in southern Ethiopia, grown during the dry season on residual moisture, for its edible tubers. It has gained importance as a "security crop" especially during the years of moisture stress and food shortage. Amochi is irritating in contact to the skin. Removal of this effect is an important question for breeding. As the first step, however we attempt to establish base line information of its breeding system and genetic variability using AFLPs. The extent of genetic differentiation among 11 populations (96 individuals) of amochi sampled along altitudinal gradients that varied from 1700 to 3200 m a.s.l. was investigated. The populations were classified in to three altitudinal groups: lowland (1700 to 2200 m a.s.l.), central-highland (2201 to 2600 m a.s.l.) and highland (2601 to 3200 m a.s.l.). Polymorphic loci (167) scored from four primer pair combinations, were used for principal component analysis (PCA), and analysis of molecular variance (AMOVA). Both PCA and unweighed pair group with arithmetic mean (UPGMA) clearly differentiated populations into their respective altitude groups, with large genetic distances. AMOVA analysis revealed 70.5%, 16.7% and 12.8% variability between altitude groups, between populations and within populations respectively. Average diversity indices within populations were also low. Since the largest proportion of variation is located between altitude groups, rather than within populations, we suggest future studies on the chemical composition, low irritation, and other desirable traits should consider populations from different altitude ranges.     

Leukemia-associated mutations within the NOTCH1 heterodimerization domain fall into at least two distinct mechanistic classes

The NOTCH1 receptor is cleaved within its extracellular domain by furin during its maturation, yielding two subunits that are held together noncovalently by a juxtamembrane heterodimerization (HD) domain. Normal NOTCH1 signaling is initiated by the binding of ligand to the extracellular subunit, which renders the transmembrane subunit susceptible to two successive cleavages within and C terminal to the heterodimerization domain, catalyzed by metalloproteases and gamma-secretase, respectively. Because mutations in the heterodimerization domain of NOTCH1 occur frequently in human T-cell acute lymphoblastic leukemia (T-ALL), we assessed the effect of 16 putative tumor-associated mutations on Notch1 signaling and HD domain stability. We show here that 15 of the 16 mutations activate canonical NOTCH1 signaling. Increases in signaling occur in a ligand-independent fashion, require gamma-secretase activity, and correlate with an increased susceptibility to cleavage by metalloproteases. The activating mutations cause soluble NOTCH1 heterodimers to dissociate more readily, either under native conditions (n = 3) or in the presence of urea (n = 11). One mutation, an insertion of 14 residues immediately N terminal to the metalloprotease cleavage site, increases metalloprotease sensitivity more than all others, despite a negligible effect on heterodimer stability by comparison, suggesting that the insertion may expose the S2 site by repositioning it relative to protective NOTCH1 ectodomain residues. Together, these studies show that leukemia-associated HD domain mutations render NOTCH1 sensitive to ligand-independent proteolytic activation through two distinct mechanisms.     

H-NS regulation of IraD and IraM antiadaptors for control of RpoS degradation

RpoS, the master sigma factor during stationary phase and under a variety of stress conditions, is regulated at multiple levels, including regulated degradation. Degradation is dependent upon ClpXP and the RssB adaptor protein. H-NS, a nucleoid-associated protein, affects the regulated degradation of RpoS; in the absence of H-NS, RpoS is stable. The mechanisms involved in this regulation were not known. We have found that H-NS inhibits the expression of iraD and iraM, the genes coding for two antiadaptor proteins that stabilize RpoS when overexpressed. The regulation by H-NS of iraM is independent from the previously demonstrated regulation by the PhoP/PhoQ two-component system. Moreover, differences in the behavior of several hns alleles are explained by a role for StpA, an H-NS-like protein, in the regulation of RpoS stability. This finding parallels recent observations for a role of StpA in regulation of RpoS stability in Salmonella.