T Cell Cross-Reactivity and Conformational Changes during TCR Engagement

All thymically selected T cells are inherently cross-reactive, yet many data indicate a fine specificity in antigen recognition, which enables virus escape from immune control by mutation in infections such as the human immunodeficiency virus (HIV). To address this paradox, we analyzed the fine specificity of T cells recognizing a human histocompatibility leukocyte antigen (HLA)-A2–restricted, strongly immunodominant, HIV gag epitope (SLFNTVATL). The majority of 171 variant peptides tested bound HLA-A2, but only one third were recognized. Surprisingly, one recognized variant (SLYNTVATL) showed marked differences in structure when bound to HLA-A2. T cell receptor (TCR) recognition of variants of these two peptides implied that they adopted the same conformation in the TCR–peptide–major histocompatibility complex (MHC) complex. However, the on-rate kinetics of TCR binding were identical, implying that conformational changes at the TCR–peptide–MHC binding interface occur after an initial permissive antigen contact. These findings have implications for the rational design of vaccines targeting viruses with unstable genomes

Rotationally Restricted 1,1′-Bis­(phenylethynyl)ferrocene Subunits in Macrocycles

The synthesis of macrocycles comprising a 1,1′-bis(phenylethynyl)ferrocene subunit was developed to increase the structural control over the spatial arrangement of the two cyclopentadienyl ligands of the ferrocene junction. The target structures were obtained through a modular strategy that enables the assembly of varying ring sizes from a common precursor. In particular, macrocycles were either formed by an ether formation reaction or by ring-closing metathesis reactions. The macrocycles were obtained in reasonable isolated yields, which allowed their thorough characterization by one- and two-dimensional NMR spectroscopy experiments, and the identity of one macrocycle was corroborated by single-crystal X-ray diffraction

The Antiviral Efficacy of HIV-Specific CD8+ T-Cells to a Conserved Epitope Is Heavily Dependent on the Infecting HIV-1 Isolate

A major challenge to developing a successful HIV vaccine is the vast diversity of viral sequences, yet it is generally assumed that an epitope conserved between different strains will be recognised by responding T-cells. We examined whether an invariant HLA-B8 restricted Nef90–97 epitope FL8 shared between five high titre viruses and eight recombinant vaccinia viruses expressing Nef from different viral isolates (clades A–H) could activate antiviral activity in FL8-specific cytotoxic T-lymphocytes (CTL). Surprisingly, despite epitope conservation, we found that CTL antiviral efficacy is dependent on the infecting viral isolate. Only 23% of Nef proteins, expressed by HIV-1 isolates or as recombinant vaccinia-Nef, were optimally recognised by CTL. Recognition of the HIV-1 isolates by CTL was independent of clade-grouping but correlated with virus-specific polymorphisms in the epitope flanking region, which altered immunoproteasomal cleavage resulting in enhanced or impaired epitope generation. The finding that the majority of virus isolates failed to present this conserved epitope highlights the importance of viral variance in CTL epitope flanking regions on the efficiency of antigen processing, which has been considerably underestimated previously. This has important implications for future vaccine design strategies since efficient presentation of conserved viral epitopes is necessary to promote enhanced anti-viral immune responses

Vinyl sulfone-based ferrocenylation reagents: applications in conjugation and bioconjugation

The easy vinyl sulfone derivatization of ferrocene allows the preparation of some effective, versatile and valuable ferrocenylation reagents. The applicability of such compounds in conjugation and bioconjugation of amine and/or thiol containing molecules and biomolecules through Michael-type addition under mild conditions that preserve the biological function of the latter is described. The feasibility of the methodology is demonstrated by the preparation of a variety of conjugates and bioconjugates (ferrocenyl terminated dendrimers and ferrocene–sugar, ferrocene–cyclodextrin, ferrocene–peptide and ferrocene–protein conjugates).Financial support was provided by Ministerio de Ciencia e Innovación (CTQ2011-29299-CO2-01)

Searching for the silver lining of the US cloud

We live in a society where more and more services are available online, and to an increasing extent, people expect that there should be a digital solution. The demand for digitalization of the public sector is increasing. However, at the same time, there are requirements for public activities to handle tax funds responsibly and not buy more expensive solutions than necessary. Here, cloud providers are often used to solve the equation of being both efficient and economical - and not least secure. The problem is that after a judgment in the Court of Justice in the European Union (Schrems II), cloud-based solutions supplied by US-based providers appear to be legally prohibited as their use violates the GDPR. GDPR complicates the digitization work by creating uncertainty about what a public organization is allowed to do. The research question to help shed light on this issue is “How can the public sector in Sweden use US cloud providers in the light of Schrems II?” This research uses design science as a research method to find the critical factors to support the use of US cloud service providers and use the factors as requirements. As the problem is practical, action research is used as a research strategy. The primary data collection methods are interviews of subject matter experts for their knowledge and direct insight into the problem, document research of mostly official documents as a knowledge base for the research with their validity and reliability, and a variant of brainstorming for new perspectives. Thematic analysis is used to analyze the results and help define the requirements for using US cloud providers in the public sector, along with explanation and root cause analysis. The GDPR is clear about third country transfers, but the additional laws and demands cause uncertainties on applying it and for which kind of data. The critical factors found are contributing laws, data classification, risk management, internal procurement,routines, employee knowledge level, and the need for documentation. These results led to a conclusion that open, public data is the only kind of data for which it is possible to use US cloud providers. After carefully examining the critical factors, some public organizations have chosen to use US cloud services for other data types, as they decided it was the safer choice. EU and the US have just agreed on the principles of a new trans-Atlantic data transfer treaty. This treaty must solve several problems to guarantee an adequate level of protection, and the probability that this will be met creates continued uncertainty in the affected organizations. One thing is clear - an organization that meets the critical requirements is firmly facing whatever future may come

Searching for the silver lining of the US cloud

We live in a society where more and more services are available online, and to an increasing extent, people expect that there should be a digital solution. The demand for digitalization of the public sector is increasing. However, at the same time, there are requirements for public activities to handle tax funds responsibly and not buy more expensive solutions than necessary. Here, cloud providers are often used to solve the equation of being both efficient and economical - and not least secure. The problem is that after a judgment in the Court of Justice in the European Union (Schrems II), cloud-based solutions supplied by US-based providers appear to be legally prohibited as their use violates the GDPR. GDPR complicates the digitization work by creating uncertainty about what a public organization is allowed to do. The research question to help shed light on this issue is “How can the public sector in Sweden use US cloud providers in the light of Schrems II?” This research uses design science as a research method to find the critical factors to support the use of US cloud service providers and use the factors as requirements. As the problem is practical, action research is used as a research strategy. The primary data collection methods are interviews of subject matter experts for their knowledge and direct insight into the problem, document research of mostly official documents as a knowledge base for the research with their validity and reliability, and a variant of brainstorming for new perspectives. Thematic analysis is used to analyze the results and help define the requirements for using US cloud providers in the public sector, along with explanation and root cause analysis. The GDPR is clear about third country transfers, but the additional laws and demands cause uncertainties on applying it and for which kind of data. The critical factors found are contributing laws, data classification, risk management, internal procurement,routines, employee knowledge level, and the need for documentation. These results led to a conclusion that open, public data is the only kind of data for which it is possible to use US cloud providers. After carefully examining the critical factors, some public organizations have chosen to use US cloud services for other data types, as they decided it was the safer choice. EU and the US have just agreed on the principles of a new trans-Atlantic data transfer treaty. This treaty must solve several problems to guarantee an adequate level of protection, and the probability that this will be met creates continued uncertainty in the affected organizations. One thing is clear - an organization that meets the critical requirements is firmly facing whatever future may come