Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

The availability of long-term records of the total ozone content (TOC) represents a valuable source of information for studies on the assessment of short-and long-term atmospheric changes and their impact on the terrestrial ecosystem. In particular, ground-based observations represent a valuable tool for validating satellite-derived products. To our knowledge, details about software packages for processing Brewer spectrophotometer measurements and for retrieving the TOC are seldom specified in studies using such datasets. The sources of the differences among retrieved TOCs from the Brewer instruments located at the Italian stations of Rome and Aosta, using three freely available codes (Brewer Processing Software, BPS; O3Brewer software; and European Brewer Network (EUBREWNET) level 1.5 products) are investigated here. Ground-based TOCs are also compared with Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites are available. The overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is within the estimated total uncertainty in the retrieval of total ozone from a Brewer spectrophotometer (1%). However, differences can be found depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a fast and dramatic drift which can affect the ozone retrievals significantly. Moreover, if daily mean values are directly generated by the software, differences can be observed due to the configuration set by the users to process single ozone measurement and the rejection rules applied to data to calculate the daily value. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometers and for stakeholders of the Brewer data products available on Web-based platforms

Is autophagy the key mechanism by which the sphingolipid rheostat controls the cell fate decision?

Sphingolipids are major constituents of biological membrane and some of them behave as second messengers involved in the cell fate decision. Ceramide and sphingosine 1-phosphate (S1P) constitute a rheostat system in which ceramide promotes cell death and S1P increases cell survival. We have shown that both sphingolipids are able to trigger autophagy with opposing outcomes on cell survival. Here we discuss and speculate on the diverging functions of the autophagic pathways induced by ceramide and S1P, respectively

Broad-Spectrum Inhibition of HIV-1 by a Monoclonal Antibody Directed against a gp120-Induced Epitope of CD4

To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1

B-cell subset alterations and correlated factors in HIV-1 infection

n/

Women for science and science for women: Gaps, challenges and opportunities towards optimizing pre-exposure prophylaxis for HIV-1 prevention

Preventing new HIV infections remains a global challenge. Young women continue to bear a disproportionate burden of infection. Oral pre-exposure prophylaxis (PrEP), offers a novel women-initiated prevention technology and PrEP trials completed to date underscore the importance of their inclusion early in trials evaluating new HIV PrEP technologies. Data from completed topical and systemic PrEP trials highlight the role of gender specific physiological and social factors that impact PrEP uptake, adherence and efficacy. Here we review the past and current developments of HIV-1 prevention options for women with special focus on PrEP considering the diverse factors that can impact PrEP efficacy. Furthermore, we highlight the importance of inclusion of female scientists, clinicians, and community advocates in scientific efforts to further improve HIV prevention strategies

HIV-Induced Damage of B Cells and Production of HIV Neutralizing Antibodies

Multiple dysfunctions take place in the B cell compartment during HIV-1 infection, comprising depletion of resting memory B cells carrying serological memory to vaccines and previously met pathogens. In addition, population of B cells characterized by the expression of exhaustion markers are enlarged during HIV-1 infection. Antibodies with the capacity to neutralize a broad range of HIV-1 isolates can be detected only in a minority of infected patients, after a year or more from acute infection. An open question is whether the inability of producing neutralizing HIV-1 antibodies is somehow linked to the B cell immunopathology observed in patients. In this research topic we invited scientists to summarize the current state of knowledge on regulation and development of B cells and antibody responses during HIV-1 infection; fifteen contributions were received comprising both reviews and original articles. The articles are related to B cell dysfunctions identified in HIV-1 infected individuals, production of different types of antibodies (neutralizing versus non neutralizing, and of different isotypes) in vivo during HIV-1 infection and the biological factors which may impact on this process, clinical potential and applications of anti-HIV antibodies and how to achieve neutralizing antibody responses to HIV-1 epitopes upon vaccination. The topic has gathered articles on front-line research undertaken in the field of B cells and antibodies in HIV-1 infection. It is our hope that the collection of articles presented in this book may be useful for new and experienced scholars in the field and add a piece to the complex puzzle of knowledge needed for the development of an HIV-1 vaccine

Editorial: HIV-Induced Damage of B Cells and Production of HIV Neutralizing Antibodies

Multiple dysfunctions take place in the B cell compartment during HIV-1 infection, comprising depletion of resting memory B cells carrying serological memory to vaccines and previously met pathogens. In addition, population of B cells characterized by the expression of exhaustion markers are enlarged during HIV-1 infection. Antibodies with the capacity to neutralize a broad range of HIV-1 isolates can be detected only in a minority of infected patients, after a year or more from acute infection. An open question is whether the inability of producing neutralizing HIV-1 antibodies is somehow linked to the B cell immunopathology observed in patients. In this research topic we invited scientists to summarize the current state of knowledge on regulation and development of B cells and antibody responses during HIV-1 infection; fifteen contributions were received comprising both reviews and original articles. The articles are related to B cell dysfunctions identified in HIV-1 infected individuals, production of different types of antibodies (neutralizing versus non neutralizing, and of different isotypes) in vivo during HIV-1 infection and the biological factors which may impact on this process, clinical potential and applications of anti-HIV antibodies and how to achieve neutralizing antibody responses to HIV-1 epitopes upon vaccination. The topic has gathered articles on front-line research undertaken in the field of B cells and antibodies in HIV-1 infection. It is our hope that the collection of articles presented in this book may be useful for new and experienced scholars in the field and add a piece to the complex puzzle of knowledge needed for the development of an HIV-1 vaccine