Performance of T-Track SARS-CoV-2, an Innovative Dual Marker RT-qPCR-Based Whole-Blood Assay for the Detection of SARS-CoV-2-Reactive T Cells.

T-cell immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a central role in the control of the virus. In this study, we evaluated the performance of T-Track SARS-CoV-2, a novel CE-marked quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay, which relies on the combined evaluation of and mRNA levels in response to the S1 and NP SARS-CoV-2 antigens, in 335 participants with or without a history of SARS-CoV-2 infection and vaccination, respectively. Of the 62 convalescent donors, 100% responded to S1 and 88.

Standardized monitoring of cytomegalovirus-specific immunity can improve risk stratification of recurrent cytomegalovirus reactivation after hematopoietic stem cell transplantation.

Recurrence of cytomegalovirus reactivation remains a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation. Monitoring cytomegalovirus-specific cellular immunity using a standardized assay might improve the risk stratification of patients. A prospective multicenter study was conducted in 175 intermediate- and high-risk allogeneic hematopoietic stem cell transplant recipients under preemptive antiviral therapy.

A comprehensive analysis of the geranylgeranylglyceryl phosphate synthase enzyme family identifies novel members and reveals mechanisms of substrate specificity and quaternary structure organization.

Geranylgeranylglyceryl phosphate synthase (GGGPS) family enzymes catalyse the formation of an ether bond between glycerol-1-phosphate and polyprenyl diphosphates. They are essential for the biosynthesis of archaeal membrane lipids, but also occur in bacterial species, albeit with unknown physiological function. It has been known that there exist two phylogenetic groups (I and II) of GGGPS family enzymes, but a comprehensive study has been missing.

Dimerization determines substrate specificity of a bacterial prenyltransferase.

We have identified the native dimer interface of heptaprenylglyceryl phosphate synthase PcrB from the bacterium Bacillus subtilis and analyzed the significance of oligomer formation for stability and catalytic activity. Computational methods predicted two different surface regions of the PcrB protomer that could be responsible for dimer formation. These bona fide interfaces were assessed both in silico and experimentally by the introduction of amino acid substitutions that led to monomerization, and by incorporation of an unnatural amino acid to allow cross-linking of the two protomers.

Functional assignment of an enzyme that catalyzes the synthesis of an archaea-type ether lipid in bacteria.

An archaea-type ether lipid in bacteria: PcrB, the bacterial homologue of the archaea-specific geranylgeranylglyceryl phosphate synthase, produces heptaprenylglyceryl phosphate in bacillales. The product becomes dephosphorylated and acetylated in vivo.

Identification and characterization of a bacterial glycerol-1-phosphate dehydrogenase: Ni(2+)-dependent AraM from Bacillus subtilis.

The exclusive presence of glycerol-1-phosphate dehydrogenases (G1PDH) has been postulated to be a key feature that distinguishes archaea from bacteria. However, homologues of G1PDH genes can be found in several bacterial species, among them the hitherto uncharacterized open reading frame araM from Bacillus subtilis. We produced recombinant AraM in Escherichia coli and demonstrate that the purified protein forms a homodimer that reversibly reduces dihydroxyacetone phosphate (DHAP) to glycerol-1-phosphate (G1P) in a NADH-dependent manner.