Targeted suppression of Dpt-specific B cells in humanized Rag2- γc- mouse model of HDM allergy

Der p 1 is one of the major allergenic molecules of Dermatophagoides pteronyssinus, causing house dust mite (HDM) allergy. The pathological B cells produce allergen-specific IgE antibodies that mediate the hypersensitivity reaction, therefore the selective elimination of these B cells is a legitimate therapeutic goal in allergy. Chimeric molecule Dp51-72 able to cross-link B cell inhibitory complement receptor type 1 and BCR on Der p 1-specific B cells was constructed. The signalling capabilities of this molecule have been tested on human B cells. A humanized mouse model of HDM allergy has been used to test the in vivo effects of the chimeric molecule administration. Administering the chimeric molecule to immunodeficient Rag2- γc- mice transferred with PBMCs from allergic patients resulted in reduction of allergen-specific IgE antibodies in the sera, and reduced infiltration of immune cells in lung histology preparations. Reduced numbers of human CD45⁺ and CD4⁺ cells in the lungs as well as inhibition of mast cell degranulation were also observed. The treatment with Dp51-72 chimera significantly decreased the local levels of anti-Dpt IgE antibodies in the bronchoalveolar lavage fluid (BALF). The binding of the chimeric molecule to tonsillar B cells triggers the tyrosine phosphorylation of 30-32 kDa protein, which is most likely involved in the inhibitory process. Administration of constructed chimeric molecules to humanized mice with developed inflammation resulted in specific suppression of disease-associated IgE antibody-producing cells and preserved lung histology. This effective approach could be further developed into a therapeutic agent for treatment of patients with HDM allergy.

Hormonal Status and Bone Health in Bulgarian Adolescents with Secondary Amenorrhoea

A prospective study was conducted including 67 girls with secondary amenorrhoea (excluding cases with PCOS, medical disorders and steroid therapy) and 38 healthy controls. The following indicators were compared between the two groups: serum levels of LH, FSH, estradiol, Ca, P and vitamin D, z- scores for bone mineral density, osteocalcin and β-CrossLaps, and prevalence of vitamin D deficiency. The group with secondary amenorrhoea was additionally subdivided according to the main cause – alimentary deficiency, excessive physical exercise and stress-induced. LH, FSH and estradiol levels were compared between the three subgroups. Ca, P and vitamin D levels in the studied and the control groups were not significantly different. The following indicators were significantly lower in the studied group compared to the control one: prolactin (291.74 mIU/ml and 336.24 mIU/ml), estradiol (322.43 pmol/ml and 475.45 pmol/ml) and LH (3.79 IU/L and 4.99 IU/L) levels, LH/FSH ratio (0.55 and 0.96) and z-score (−0.48 and 0.47). FSH was significantly higher in the studied group (6.90 IU/L) compared to the control one (5.44 IU/L). The serum levels of LH and estradiol were significantly lower in the subgroup with secondary stress-induced amenorrhoea (1.73 IU/L and 220.60 pmol/ml) compared to the subgroups with amenorrhoea due to alimentary deficiency (4.68 IU/L and 394.68 pmol/ml) or extreme physical exercise (3.74 IU/L and 323.91 pmol/ml). In girls with secondary amenorrhea, the levels of osteocalcin were significantly lower compared to the ones in the control group (26.41 and 30.99 ng/ml) while β-CrossLaps levels were similar (0.34 and 0.98 ng/mL). High prevalence of vitamin D deficiency was observed in both the patients with secondary amenorrhoea (71.6%) and the control group (65.8%). Significant changes in hormone levels and bone health were observed in Bulgarian adolescent girls with secondary amenorrhoea as well as high prevalence of vitamin D deficiency in both the studied and the control groups. Early diagnosis and timely interventions are needed to improve bone health in adolescents with secondary amenorrhoea.

Cellular, Antibody and Cytokine Pathways in Children with Acute SARS-CoV-2 Infection and MIS-C-Can We Match the Puzzle?

The newly identified strain of the Coronaviridae family called severe acute respiratory syndrome (SARS-CoV-2) recently became the most significant health threat for adults and children. Some main predictors of severe clinical course in patients with SARS-CoV-2 infection are age and concomitant health conditions. Therefore, the proper evaluation of SARS-CoV-2-specific immunity is urgently required to understand and predict the spectrum of possible clinical phenotypes and recommend vaccination options and regimens in children. Furthermore, it is critical to characterize the nature of SARS-CoV-2-specific immune responses in children following asymptomatic infection and COVID-19 and other related conditions such as multisystem inflammatory syndrome (MIS-C), para-infectious and late postinfectious consequences. Recent studies involving children revealed a variety of cytokines, T cells and antibody responses in the pathogenesis of the disease. Moreover, different clinical scenarios in children were observed-asymptomatic seroprevalence, acute SARS-CoV-2 infection, and rarely severe COVID-19 with typical cytokine storm, MIS-C, long COVID-19, etc. Therefore, to gain a better clinical view, adequate diagnostic criteria and treatment algorithms, it is essential to create a realistic picture of the immunological puzzle of SARS-CoV-2 infection in different age groups. Finally, it was demonstrated that children may exert a potent and prolonged adaptive anti-SARS-CoV-2 immune response, with significant cross-reactions against other human Corona Viruses, that might contribute to disease sparing effect in this age range. However, the immunopathology of the virus has to be elucidated first.

Allergen-Specific IgE and IgG4 as Biomarkers for Immunologic Changes during Subcutaneous Allergen Immunotherapy

(1) Background: Biomarkers of efficacy for subcutaneous immunotherapy (SCIT) on allergic rhinitis have not been evaluated in details. The present study aims to assess the relevance of measuring of sIgE, sIgG4 and IgE/IgG4 ratio during SCIT in patients with allergic rhinitis; (2) Methods: 20 patients, 13 men and 7 women aged 19 to 58 years, with clinically manifested seasonal and perennial allergic rhinitis were studied. At the initiation and in the end of the three-year course of SCIT serum allergen-specific IgE and IgG4 were measured with ImmunoCAP system. The sIgE/sIgG4 ratio was calculated as a biomarker for immunologic effectiveness; (3) Results: There was a significant increase of sIgG4 antibodies (p < 0.05), while at the end of SCIT for the sIgE levels no significant changes were seen (p > 0.05). Moreover, 90% of patients showed a decrease of the IgE/IgG4 ratio; (4) Conclusions: In most of treated patients with AR, SCIT with Bulgarian allergen products leads to clear immunological changes. After a 3-year of SCIT there is a significant increase in allergen specific IgG4 levels and both decrease of sIgE and IgE/IgG4 ratio. sIgE, sIgG4 and IgE/IgG4 ratio can be used as a substantial biomarker for predicting immunological effectiveness of SCIT.

Requirements for Data Quality Metrics

Data quality and especially the assessment of data quality have been intensively discussed in research and practice alike. To support an economically oriented management of data quality and decision making under uncertainty, it is essential to assess the data quality level by means of well-founded metrics. However, if not adequately defined, these metrics can lead to wrong decisions and economic losses. Therefore, based on a decision-oriented framework, we present a set of five requirements for data quality metrics. These requirements are relevant for a metric that aims to support an economically oriented management of data quality and decision making under uncertainty. We further demonstrate the applicability and efficacy of these requirements by evaluating five data quality metrics for different data quality dimensions. Moreover, we discuss practical implications when applying the presented requirements.

A slow-cycling subpopulation of melanoma cells with highly invasive properties

Melanoma is a heterogeneous tumor with different subpopulations showing different proliferation rates. Slow-cycling cells were previously identified in melanoma, but not fully biologically characterized. Using the label-retention method, we identified a subpopulation of slow-cycling cells, defined as label-retaining cells (LRC), with strong invasive properties. We demonstrate through live imaging that LRC are leaving the primary tumor mass at a very early stage and disseminate to peripheral organs. Through global proteome analyses, we identified the secreted protein SerpinE2/protease nexin-1 as causative for the highly invasive potential of LRC in melanomas.

Defective N-acetylaspartate catabolism reduces brain acetate levels and myelin lipid synthesis in Canavan's disease

Canavan's disease (CD) is a fatal, hereditary disorder of CNS development that has been linked to mutations in the gene for the enzyme aspartoacylase (ASPA) (EC 3.5.1.15). ASPA acts to hydrolyze N-acetylaspartate (NAA) into l-aspartate and acetate, but the connection between ASPA deficiency and the failure of proper CNS development is unclear. We hypothesize that one function of ASPA is to provide acetate for the increased lipid synthesis that occurs during postnatal CNS myelination. The gene encoding ASPA has been inactivated in the mouse model of CD, and here we show significant decreases in the synthesis of six classes of myelin-associated lipids, as well as reduced acetate levels, in the brains of these mice at the time of peak postnatal CNS myelination. Analysis of the lipid content of white matter from a human CD patient showed decreased cerebroside and sulfatide relative to normal white matter. These results demonstrate that myelin lipid synthesis is significantly compromised in CD and provide direct evidence that defective myelin synthesis, resulting from a deficiency of NAA-derived acetate, is involved in the pathogenesis of CD.

Variability of the N-protein and the intergenic region of the S RNA of tomato spotted wilt tospovirus (TSWV)

The genetic heterogeneity of the N protein gene and the intergenic region (IGR) of the S RNA from tomato spotted wilt virus (TSWV) isolates, collected in Bulgaria, were compared with isolates from other parts of the world. The results substantiated the highly conserved nature of the N protein. Twenty six independent sequences revealed only seven variable amino acid positions, common to all isolates. The type of amino acids present in these positions seems to be independent of the geographical origin. In contrast to the structural N protein, comparisons of the related IGR-sequences led to clusters correlated with the geographical origin of the isolates. Although the overall sequence homology in the IGRs was much lower than for the N proteins, three conserved parts within this region were identified. The outstanding part was a central area of 31 nucleotides with a significantly increased GC-content. This was located in both viral- and viral-complement RNA at structures with similar foldings, which led to the assumption that this stabilised structure, rather than a sequence motive, might serve as a transcription terminator during the synthesis of the two mRNAs from the ambisense segments.

Immunohistological localization of regenerating protein in ocular structures

PURPOSE

To investigate the presence of pancreatic stone protein (PSP)/reg (regenerating) protein in eyes and extraocular structures of rabbits, monkeys and man, according to species and age.

METHODS

Rabbit eyes, with normal or de-epithelialized corneas, were taken from albino and pigmented animals. Monkey eyes were taken from cynomolgus monkeys, 2 years old. Stillborn and adult human eyes were obtained after autopsy. They were studied by immunohistochemistry methods, using a monoclonal antibody raised against human PSP.

RESULTS

On rabbit ocular structures, the anti-PSP monoclonal antibody showed a strong reactivity at the level of basement membranes and basal poles of the cells of corneal and conjunctival epithelia and on basement membranes of skin and palpebral conjunctiva in eyelids. On de-epithelialized rabbit eyes, the remaining basement membrane was labeled while, along the re-epithelialization, the anti-PSP reactivity appeared with the migrating cells which cover the denuded cornea. On young monkeys, the whole corneal epithelium was reactive. Similar results were obtained from stillborn eyes, whereas no reactivity was detected on autopsy specimens from aged persons.

CONCLUSIONS

As in other tissues and organs, the reg protein, in the eye, is found in structures known for their continuous and rapid renewal. This protein seems not to exist (or persist) in eyes from aged donors while it is strongly expressed in young donor eyes (monkey, stillborn baby) as well as in regenerating corneal epithelium. These findings enforce the hypothesis about the involvement of reg protein in cell proliferation and differentiation phenomena and its probable correlation with aging.