Interleukin-21 promotes Type-1 activation and cytotoxicity of CD56CD16 natural killer cells during kidney allograft antibody-mediated rejection showing a new link between adaptive and innate humoral allo-immunity.

The role of Natural killer (NK) cells during kidney allograft antibody-mediated rejection (ABMR) is increasingly recognized, but an in-depth characterization of mechanisms that contribute to such immune response is still under investigation. Here, we characterized phenotypic, functional, and transcriptomic profiles of peripheral blood circulating and allograft infiltrating CD56CD16 NK cells during anti-HLA donor-specific antibody (DSA)+ ABMR. Cross-sectional analyses performed in 71 kidney transplant recipients identified a unique phenotypic circulating CD56CD16 NK cell cluster expanded in DSA+ ABMR.

T-bet+CD27+CD21- B cells poised for plasma cell differentiation during antibody-mediated rejection of kidney transplants.

Alloimmune responses driven by donor-specific antibodies (DSAs) can lead to antibody-mediated rejection (ABMR) in organ transplantation. Yet, the cellular states underlying alloreactive B cell responses and the molecular components controlling them remain unclear. Using high-dimensional profiling of B cells in a cohort of 96 kidney transplant recipients, we identified expanded numbers of CD27+CD21- activated memory (AM) B cells that expressed the transcription factor T-bet in patients who developed DSAs and progressed to ABMR.

Coordinated Circulating T Follicular Helper and Activated B Cell Responses Underlie the Onset of Antibody-Mediated Rejection in Kidney Transplantation.

Background: Although antibody-mediated rejection (ABMR) has been long recognized as a leading cause of allograft failure after kidney transplantation, the cellular and molecular processes underlying the induction of deleterious donor-specific antibody (DSA) responses remain poorly understood.

Methods: Using high-dimensional flow cytometry, assays, and RNA sequencing, we concomitantly investigated the role of T follicular helper (T) cells and B cells during ABMR in 105 kidney transplant recipients.

Results: There were 54 patients without DSAs; of those with DSAs, ABMR emerged in 20 patients, but not in 31 patients.

Impact of Induction Therapy on Circulating T Follicular Helper Cells and Subsequent Donor-Specific Antibody Formation After Kidney Transplant.

Introduction: The cellular events that contribute to generation of donor-specific anti-HLA antibodies (DSA) post-kidney transplantation (KTx) are not well understood. Characterization of such mechanisms could allow tailoring of immunosuppression to benefit sensitized patients.

Methods: We prospectively monitored circulating T follicular helper (cT) cells in KTx recipients who received T-cell depleting (thymoglobulin,  = 54) or T-cell nondepleting (basiliximab,  = 20) induction therapy from pre-KTx to 1 year post-KTx and assessed their phenotypic changes due to induction and DSA occurrence, in addition to healthy controls ( = 13), for a total of 307 blood samples.

Influence of the Novel ATP-Competitive Dual mTORC1/2 Inhibitor AZD2014 on Immune Cell Populations and Heart Allograft Rejection.

Background: Little is known about how new-generation adenosine triphosphate-competitive mechanistic target of rapamycin (mTOR) kinase inhibitors affect immunity and allograft rejection.

Methods: mTOR complex (C) 1 and 2 signaling in dendritic cells and T cells was analyzed by Western blotting, whereas immune cell populations in normal and heart allograft recipient mice were analyzed by flow cytometry. Alloreactive T cell proliferation was quantified in mixed leukocyte reaction; intracellular cytokine production and serum antidonor IgG levels were determined by flow analysis and immunofluorescence staining used to detect IgG in allografts.

Phenotype, function, and differentiation potential of human monocyte subsets.

Human monocytes have been grouped into classical (CD14++CD16-), non-classical (CD14dimCD16++), and intermediate (CD14++CD16+) subsets. Documentation of normal function and variation in this complement of subtypes, particularly their differentiation potential to dendritic cells (DC) or macrophages, remains incomplete. We therefore phenotyped monocytes from peripheral blood of healthy subjects and performed functional studies on high-speed sorted subsets.

Evaluation of the Gastrointestinal Tract as Potential Route of Primary Polyomavirus Infection in Mice.

Background: Detection of Polyomavirus (PyV) DNA in metropolitan rivers worldwide has led to the suggestion that primary viral infection can occur by the oral route. The aim of this study was to test this notion experimentally.

Methods: Mouse PyV (MPyV) was used to infect C57BL/6J mice by the nasal or intragastric route.

The polyomavirus BK large T-antigen-derived peptide elicits an HLA-DR promiscuous and polyfunctional CD4+ T-cell response.

BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays.

Airborne virus capture and inactivation by an electrostatic particle collector.

Airborne virus capture and inactivation were studied in an electrostatic precipitator (ESP) at applied voltages from -10 to +10 kV using aerosolized bacteriophages T3 and MS2. For each charging scenario, samples were collected from the effluent air stream and assayed for viable phages using plaque assays and for nucleic acids using quantitative polymerase chain reaction (qPCR) assays. At higher applied voltages, more virus particles were captured from air with maximum log reductions of 6.

HLA-A01-, -A03-, and -A024-binding nanomeric epitopes in polyomavirus BK large T antigen.

Polyomavirus BK (BKV) infections are increasingly recognized. The development of immune-monitoring strategies against BKV requires definition of antigenic epitopes. Bioinformatic algorithms were used to identify 60 BKV large T-antigen (LT-Ag) peptides predicted to bind HLA class I alleles.

Identification of species-specific and cross-reactive epitopes in human polyomavirus capsids using monoclonal antibodies.

The human antibody response to polyomavirus capsid proteins is not well characterized. Recombinant BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40) virus-like particles (VLP) were produced in a baculovirus system, and mouse monoclonal antibodies (mAbs) to these proteins were generated using standard methods. Nine of 12 BKV mAbs showed neutralizing activity.

Validation of BKV large T-antigen ATP-binding site as a target for drug discovery.

BK virus large T antigen (LTA) is a hexameric protein with a helicase activity that is powered by ATP hydrolysis. A mutant virus with Lys420Ala, Arg421Ala, and Asp504Ala mutations at the ATP binding sites showed marked reduction in viral fitness. This observation indicates that high throughput screening for ATPase inhibitors will be valid strategy to discover anti-BKV drugs.

Evaluation of chemical indicators for tracking and apportionment of phosphorus sources to Table Rock Lake in Southwest Missouri, USA.

This work evaluated the suitability of selected chemical species as indicators for tracking and apportionment of point and non-point phosphorus sources within the Table Rock Lake watershed in Southwest Missouri, USA. The species were evaluated with respect to their uniqueness to specific source types, their ability to be detected in both sources and receiving waters, and the consistency of their concentration ratios to phosphorus. Four sampling events were conducted at 15 sample locations in one year to collect water samples for measuring the concentrations of total and dissolved phosphorus, seven anions, and 19 major and trace elements.

Charge reduced electrospray size spectrometry of mega- and gigadalton complexes: whole viruses and virus fragments.

The ability to analyze and identify large macromolecular complexes whose molecular weight is beyond the analyzable range of mass spectrometry is of great interest. The size of such complexes makes them suitable for analysis via mobility size spectrometry. In this work, charge reduced electrospray size spectrometry was used for the analysis of bacteriophage viruses with total molecular masses ranging from 3.