694 research outputs found
The co-chaperone p23 controls root development through the modulation of auxin distribution in the Arabidopsis root meristem.
Homologues of the p23 co-chaperone of HSP90 are present in all eukaryotes, suggesting conserved functions for this protein throughout evolution. Although p23 has been extensively studied in animal systems, little is known about its function in plants. In the present study, the functional characterization of the two isoforms of p23 in Arabidopsis thaliana is reported, suggesting a key role of p23 in the regulation of root development. Arabidopsis p23 mutants, for either form, show a short root length phenotype with a reduced meristem length. In the root meristem a low auxin level associated with a smaller auxin gradient was observed. A decrease in the expression levels of PIN FORMED PROTEIN (PIN)1, PIN3, and PIN7, contextually to an inefficient polar localization of PIN1, was detected. Collectively these results suggest that both Arabidopsis p23 isoforms are required for root growth, in particular in the maintenance of the root meristem, where the proteins are located
KDC1, a Novel Carrot Root Hair K+Channel CLONING, CHARACTERIZATION, AND EXPRESSION IN MAMMALIAN CELLS
Potassium is an essential nutrient which plays an important role in many aspects of plant growth and development. Plants have developed a number of highly specific mechanisms to take up potassium from the soil; these include the expression of K+ transporters and potassium channels in root cells. Despite the fact that root epidermal and hair cells are in direct contact with the soil, the role of these tissues in K+uptake is not well understood. Here we report the molecular cloning and functional characterization of a novel potassium channel KDC1 which forms part of a new subfamily of plant Kinchannels. Kdc1 was isolated from carrot root RNA andin situ hybridization experiments show Kdc1 to be highly expressed in root hair cells. Expressing the KDC1 protein in Chinese hamster ovary cells identified it as a voltage and pH-dependent inwardly rectifying potassium channel. An electrophysiological analysis of carrot root hair protoplasts confirmed the biophysical properties of the Kdc1 gene product (KDC1) in the heterologous expression system. KDC1 thus represents a major K+ uptake channel in carrot root hair cells
Programmed cell death induced by high levels of cytokinin in Arabidopsis cultured cells is mediated by the cytokinin receptor CRE1/AHK4
High levels of cytokinins (CKs) induce programmed cell death (PCD) both in animals and plant cells. High levels of the CK benzylaminopurine (BA) induce PCD in cultured cells of Arabidopsis thaliana by accelerating a senescence process characterized by DNA laddering and expression of a specific senescence marker. In this report, the question has been addressed whether members of the small family of Arabidopsis CK receptors (AHK2, AHK3, CRE1/AHK4) are required for BA-induced PCD. In this respect, suspension cell cultures were produced from selected receptor mutants. Cell growth and proliferation of all receptor mutant and wild-type cell cultures were similar, showing that the CK receptors are not required for these processes in cultured cells. The analysis of CK metabolites instead revealed differences between wild-type and receptor mutant lines, and indicated that all three receptors are redundantly involved in the regulation of the steady-state levels of isopentenyladenine- and trans-zeatin-type CKs. By contrast, the levels of cis-zeatin-type CKs were controlled mainly by AHK2 and AHK3. To study the role of CK receptors in the BA-induced PCD pathway, cultured cells were analysed for their behaviour in the presence of high levels of BA. The results show that CRE1/AHK4, the strongest expressed CK receptor gene of this family in cultured cells, is required for PCD, thus linking this process to the known CK signalling pathway
Modelling opinion formation by means of kinetic equations
In this chapter, we review some mechanisms of opinion dynamics that can be modelled by kinetic equations. Beside the sociological phenomenon of compromise, naturally linked to collisional operators of Boltzmann kind, many other aspects, already mentioned in the sociophysical literature or no, can enter in this framework. While describing some contributions appeared in the literature, we enlighten some mathematical tools of kinetic theory that can be useful in the context of sociophysics
Immunogenicity and safety after the third dose of BNT162b2 anti-SARS-CoV-2 vaccine in patients with solid tumors on active treatment: a prospective cohort study
Background: Although a full course of coronavirus disease 2019 (COVID-19) vaccine is effective in cancer patients, the duration of the protection and the efficacy of a booster dose against the new variants remain unknown. We prospectively evaluated the immunogenicity of the third dose of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BNT162b2 messenger RNA vaccine in cancer patients undergoing active treatment. Patients and methods: Patients with solid cancer, vaccinated with a booster dose during active treatment, were enrolled in this study. Patients were classified into SARS-CoV-2 naïve (without previous COVID-19 infection) and SARS-CoV-2 experienced (with previous COVID-19 infection). Neutralizing antibody (NT Ab) titer and total anti-Spike immunoglobulin G (IgG) concentration were quantified in serum. Heparinized whole blood samples were used for SARS-CoV-2 Interferon Gamma Release Assay (IGRA). The primary endpoint was to assess the increase of IgG antibody level between baseline and 3 weeks after the booster. Results: One hundred and forty-two consecutive patients were recruited. In SARS-CoV-2-naïve subjects, the median level of IgG was 157 BAU/ml [interquartile range (IQR) 62-423 BAU/ml] at T0 and reached a median of 2080 BAU/ml (IQR 2080-2080 BAU/ml) at 3 weeks after booster administration (T1; P < 0.0001). A median 16-fold increase of SARS-CoV-2 NT Ab titer (IQR 4-32) was observed in naïve subjects (from median 20, IQR 10-40, to median 640, IQR 160-640; P < 0.0001). Median interferon-γ level at T1 was significantly higher than that measured at T0 in SARS-CoV-2-naïve subjects (P = 0.0049) but not in SARS-CoV-2-experienced patients. The median level of SARS-CoV-2 NT Abs was 32-fold lower against Omicron compared to the wild-type strain (P = 0.0004) and 12-fold lower compared to the Delta strain (P = 0.0110). Conclusions: The third dose is able to trigger both the humoral and the cell-mediated immune response in cancer patients on active treatment. Our preliminary data about the neutralization of the SARS-CoV-2 vaccine against variants of concern seem to confirm the lower vaccine activity
Allergy in adolescent population (14-18 years) living in campania region (southern Italy). a multicenter study
Adolescents (Ad) constitute a difficult to manage population among individuals suffering from asthma. The aim of our study was to assess the prevalence, clinical characteristics and age of onset of allergic sensitization and clinical symptoms in a sample of atopic Ad living in the Campania region (Southern Italy). Sixteen Allergy units or Centers belonging to the Italian Association of Hospital and Territorial Allergologists (AAIITO, Campania region) participated in this cross-sectional study. A case report form (CRF) was specifically designed for this study and commercial allergen extracts used for screening SPTs were provided by ALK-Abelló Group (Milan, Italy). A total of 443 patients were examined (females, f 220, 49.6 %; males, m 223, 50.3%). Dust mites represent the most common sensitizing agents in allergic Ad living in Campania region (Dermatoph. pteronyssinus 67.4% and Dermatoph. farinae 66.5%), followed by Parietaria (58.9%), grasses (45.8%), Artemisia vulgaris (16.7%), Olea Europaea (32.2%), dog dander (17.1%), cat dander (20.0%), Alternaria alternata (8.1%), Cupressus sempervirens (4.9%), Betula pendula (4.7%), other allergens (19.4%). An interesting comparison has been made between clinical data of our Ad with data of elderly patients (E). The role of allergic sensitization is significantly higher in Ad compared to E. Dermatophagoides pteronyssinus is the first sensitizing allergen in Ad and the last in E. Parietaria constitutes the first sensitizing pollen both in Ad and E, the percentage of sensitization is higher in Ad. Another important difference is the higher prevalence of As, as only symptom, in E compared to Ad (19.7% versus 7.6%). In conclusion, our findings confirm the high prevalence and clinical significance of airway allergic sensitization in the adolescents living in Campania region
Analysis of the humoral and cellular immune response after a full course of BNT162b2 anti-SARS-CoV-2 vaccine in cancer patients treated with PD-1/PD-L1 inhibitors with or without chemotherapy: an update after 6 months of follow-up
Background: The durability of immunogenicity of SARS-CoV-2 vaccination in cancer patients remains to be elucidated. We prospectively evaluated the immunogenicity of the vaccine in triggering both the humoral and the cell-mediated immune response in cancer patients treated with anti-programmed cell death protein 1/programmed death-ligand 1 with or without chemotherapy 6 months after BNT162b2 vaccine. Patients and methods: In the previous study, 88 patients were enrolled, whereas the analyses below refer to the 60 patients still on immunotherapy at the time of the follow-up. According to previous SARS-CoV-2 exposure, patients were classified as SARS-CoV-2-naive (without previous SARS-CoV-2 exposure) and SARS-CoV-2-experienced (with previous SARS-CoV-2 infection). Neutralizing antibody (NT Ab) titer against the B.1.1 strain and total anti-spike immunoglobulin G concentration were quantified in serum samples. The enzyme-linked immunosorbent spot assay was used for quantification of anti-spike interferon-γ (IFN-γ)-producing cells/106 peripheral blood mononuclear cells. Fifty patients (83.0%) were on immunotherapy alone, whereas 10 patients (7%) were on chemo-immunotherapy. We analyzed separately patients on immunotherapy and patients on chemo-immunotherapy. Results: The median T-cell response at 6 months was significantly lower than that measured at 3 weeks after vaccination [50 interquartile range (IQR) 20-118.8 versus 175 IQR 67.5-371.3 IFN-γ-producing cells/106 peripheral blood mononuclear cells; P < 0.0001]. The median reduction of immunoglobulin G concentration was 88% in SARS-CoV-2-naive subjects and 2.1% in SARS-CoV-2-experienced subjects. SARS-CoV-2 NT Ab titer was maintained in SARS-CoV-2-experienced subjects, whereas a significant decrease was observed in SARS-CoV-2-naive subjects (from median 1 : 160, IQR 1 : 40-1 : 640 to median 1 : 20, IQR 1 : 10-1 : 40; P < 0.0001). A weak correlation was observed between SARS-CoV-2 NT Ab titer and spike-specific IFN-γ-producing cells at both 6 months and 3 weeks after vaccination (r = 0.467; P = 0.0002 and r = 0.428; P = 0.0006, respectively). Conclusions: Our work highlights a reduction in the immune response in cancer patients, particularly in SARS-CoV-2-naive subjects. Our data support administering a third dose of COVID-19 vaccine to cancer patients treated with programmed cell death protein 1/programmed death-ligand 1 inhibitors
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