Novel bimodal TRBD1-TRBD2 rearrangements with dual or absent D-region contribute to TRB V-(D)-J combinatorial diversity

T-cell receptor (TR) diversity of the variable domains is generated by recombination of both the alpha (TRA) and beta (TRB) chains. The textbook process of TRB chain production starts with TRBD and TRBJ gene rearrangement, followed by the rearrangement of a TRBV gene to the partially rearranged D-J gene. Unsuccessful V-D-J TRB rearrangements lead to apoptosis of the cell. Here, we performed deep sequencing of the poorly explored pool of partial TRBD1-TRBD2 rearrangements in T-cell genomic DNA. We reconstructed full repertoires of human partial TRBD1-TRBD2 rearrangements using novel sequencing and validated them by detecting V-D-J recombination-specific byproducts: excision circles containing the recombination signal (RS) joint 5’D2-RS – 3’D1-RS. Identified rearrangements were in compliance with the classical 12/23 rule, common for humans, rats, and mice and contained typical V-D-J recombination footprints. Interestingly, we detected a bimodal distribution of D-D junctions indicating two active recombination sites producing long and short D-D rearrangements. Long TRB D-D rearrangements with two D-regions are coding joints D1-D2 remaining classically on the chromosome. The short TRB D-D rearrangements with no D-region are signal joints, the coding joint D1-D2 being excised from the chromosome. They both contribute to the TRB V-(D)-J combinatorial diversity. Indeed, short D-D rearrangements may be followed by direct V-J2 recombination. Long D-D rearrangements may recombine further with J2 and V genes forming partial D1-D2-J2 and then complete V-D1-D2-J2 rearrangement. Productive TRB V-D1-D2-J2 chains are present and expressed in thousands of clones of human antigen-experienced memory T cells proving their capacity for antigen recognition and actual participation in the immune response

Unique Electron Polarimeter Analyzing Power Comparison and Precision Spin-Based Energy Measurement

Precision measurements of the relative analyzing powers of five electron beam polarimeters, based on Compton, Moller, and Mott scattering, have been performed using the CEBAF accelerator at the Thomas Jefferson National Accelerator Facility ( Jefferson Laboratory). A Wien filter in the 100 keV beam line of the injector was used to vary the electron spin orientation exiting the injector. High statistical precision measurements of the scattering asymmetry as a function of the spin orientation were made with each polarimeter. Since each polarimeter receives beam with the same magnitude of polarization, these asymmetry measurements permit a high statistical precision comparison of the relative analyzing powers of the five polarimeters. This is the first time a precise comparison of the analyzing powers of Compton, Moller, and Mott scattering polarimeters has been made. Statistically significant disagreements among the values of the beam polarization calculated from the asymmetry measurements made with each polarimeter reveal either errors in the values of the analyzing power or failure to correctly include all systematic effects. The measurements reported here represent a first step toward understanding the systematic effects of these electron polarimeters. Such studies are necessary to realize high absolute accuracy (ca. 1%) electron polarization measurements, as required for some parity violation measurements planned at Jefferson Laboratory. Finally, a comparison of the value of the spin orientation exiting the injector that provides maximum longitudinal polarization in each experimental hall leads to an independent and very precise ( better than 10-4) absolute measurement of the final electron beam energy

TCRs with segment TRAV9-2 or a CDR3 histidine are overrepresented among nickel-specific CD4+ T cells

Background: Nickel is the most frequent cause of T cell-mediated allergic contact dermatitis worldwide. In vitro, CD4+ T cells from all donors respond to nickel but the involved αβ T cell receptor (TCR) repertoire has not been comprehensively analyzed. Methods: We introduce CD154 (CD40L) upregulation as a fast, unbiased, and quantitative method to detect nickel-specific CD4+ T cells ex vivo in blood of clinically characterized allergic and non allergic donors. Naïve (CCR7+ CD45RA+) and memory (not naïve) CD154+ CD4+ T cells were analyzed by flow cytometry after 5 hours of stimulation with 200 µmol/L NiSO4 ., TCR α- and β-chains of sorted nickel-specific and control cells were studied by high-throughput sequencing. Results: Stimulation of PBMCs with NiSO4 induced CD154 expression on ~0.1% (mean) of naïve and memory CD4+ T cells. In allergic donors with recent positive patch test, memory frequencies further increased ~13-fold and were associated with markers of in vivo activation. CD154 expression was TCR-mediated since single clones could be specifically restimulated. Among nickel-specific CD4+ T cells of allergic and non allergic donors, TCRs expressing the α-chain segment TRAV9-2 or a histidine in their α- or β-chain complementarity determining region 3 (CDR3) were highly overrepresented. Conclusions: Induced CD154 expression represents a reliable method to study nickel-specific CD4+ T cells. TCRs with particular features respond in all donors, while strongly increased blood frequencies indicate nickel allergy for some donors. Our approach may be extended to other contact allergens for the further development of diagnostic and predictive in vitro tests

Coordination of NK cell markers expression and IgG response in hCMV infection

Human cytomegalovirus (hCMV) is a prevalent virus that affects a large proportion of the population worldwide. Natural Killer (NK) cells are essential immune cells that play a crucial role in controlling hCMV infection. Despite the wide spread of hCMV infection, there is still not enough data related to the association between innate and adaptive immunity. This study investigated the coordination between some of the NK cell markers expression and humoral immune response during hCMV infection. Thirty-three samples obtained from different healthy donors were investigated. The anti-hCMV IgG antibody titer was measured in serum samples, and expression of NKG2C, HLA-DR, CD57, KIR2DL2/DL3, and KIR2DL1 were analyzed in CD56+CD3- cells in PBMC samples by flow cytometry. To evaluate the dependence of proportions of different NK cell subsets on IgG titers, cluster analysis was first performed on all the obtained data, resulting in the identification of four main clusters. The identified clusters demonstrated a dependence on the levels of hCMV antibodies, according to which clusters corresponding to seronegative and low-positive were grouped. The results confirmed that hCMV infection leads to an expansion of NK cell populations expressing the NKG2C marker, which correlates with higher levels of IgG response to hCMV. Besides, we identified increased HLA-DR+ and decreased of KIR2DL1+ NK cells proportions in the middle anti-CMV-IgG level group compared to samples obtained from seronegative and low-positive donors. Moreover, the statistically significant negative correlation was found between KIR2DL1+NK cell percentage and anti-CMV IgG antibody titer, while the positive correlation between HLA-DR+NK cell proportion and the IgG level was noticed only without the cluster corresponded to high level of anti-hCMV IgG. In this cohort, we did not find any association between KIR2DL3 and CD57 expression in NK cells and levels of IgG response to hCMV. This may indicate that different subsets of NK cells may have distinct roles in regulating humoral immunity to hCMV. Overall, the results of the study provide valuable insights into the coordination of NK cell marker expression and IgG response in hCMV infection

Space-Time Evolution of Ultrarelativistic Quantum Dipoles in Quantum Electrodynamics

We discuss space-time evolution of ultrarelativistic quantum dipole in QED. We show that the space-time evolution can be described, in a certain approximation, by means of a regularized wave function, whose parameters are determined by the process of the dipole creation by a local current. We derive using these wave functions the dipole expansion law, that is found to coincide parametrically in the leading order with the one suggested by Farrar, Frankfurt,Liu and Strikman.Comment: 15 page

Early IgE production is associated with accumulation of CD11b+ classical dendritic cells and CD11b+CD11c- macrophages in subcutaneous adipose tissue

In view of increased incidence of IgE-mediated diseases in Russia and worldwide, the efforts of various research groups are focused on studying the mechanisms that trigger the process of switching B-lymphocytes to IgE synthesis upon human exposure to harmless allergens, including the role of various antigen-presenting cells (APCs) in this process. However, the role of distinct APCs upon long-term penetration of low antigen doses via the tissue barriers, is yet poorly understood, as well as specific features of these events upon entrance of the antigen through the subcutaneous adipose tissue which contains tissueassociated lymphoid clusters (TALC).The aim of this work was to determine the relationship between the local accumulation of various APCs in the subcutaneous adipose tissue and development of early IgE production in a clinically relevant experimental model of allergy with long-term administration of low allergen doses. In this experimental model, specific IgE synthesis is induced, with minimal concomitant IgG production, thus mimicking the situation observed in patients with clinically sound allergies. BALB/c mice were immunized for 4 weeks subcutaneously in the withers area or intraperitoneally with low (100 ng) or high (10 μg) doses of the model allergen (ovalbumin). Blood samples were taken weekly from mice for ELISA testing, to determine the production of specific antibodies. Provocation tests were performed with high dose of the allergen, and adipose tissue samples were taken from the site of antigen injection for flow cytometric assays, in order to evaluate the contents of various APC subpopulations. Specific IgE production was induced mainly by subcutaneous injection of the antigen at low doses (100 ng) into the area of withers. When using this experimental regimen, we observed accumulation of classical CD11b+ cells in adipose tissue at the withers site, but not in the peritoneal adipose tissue, in absence of CD11b- classical, inflammatory or plasmacytoid, dendritic cells. These findings coincided in time with increased production of specific IgE on days +14 to +21. Accumulation of CD11b+CD11c- macrophages and their CD206+ M2 subpopulations at early terms (days +7 and +21) was also observed only after subcutaneous injection of the antigen into the withers area. The high-dose antigen injection (10 μg) which mediated IgG1 production to greater extent than production of IgE, led to earlier accumulation of CD11b+ classical dendritic cells (on day 7th), and to the absence of macrophage accumulation at later stages (day 21th). Thus, the early start of specific IgE production upon low-dose injection of the antigen into the subcutaneous adipose tissue may be associated with its presentation by CD11b+ classical dendritic cells in the presence of CD11b+CD11c- macrophages

Observation of Parity Nonconservation in Moller Scattering

We report a measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -175 +/- 30 (stat.) +/- 20 (syst.) parts per billion. This first direct observation of parity nonconservation in Moller scattering leads to a measurement of the electron's weak charge at low energy Q^e_W = -0.053 +/- 0.011. This is consistent with the Standard Model expectation at the current level of precision: sin^2\theta_W(M_Z)_MSbar = 0.2293 +/- 0.0024 (stat.) +/- 0.0016 (syst.) +/- 0.0006 (theory).Comment: Version 3 is the same as version 2. These versions contain minor text changes from referee comments and a change in the extracted value of Q^e_W and sin^2\theta_W due to a change in the theoretical calculation of the bremsstrahulung correction (ref. 16