TCR+CD4-CD8- T cells in antigen-specific MHC class I-restricted T-cell responses after allogeneic hematopoietic stem cell transplantation.

Human TCRαβ(+) CD4(-)CD8(-) double-negative (DN) T cells represent a minor subset in peripheral blood, yet are important in infectious diseases and autoimmune responses. We examined the frequency of DN T cells in 17 patients after allogeneic hematopoietic stem cell transplantation (aHSCT) at 1, 2, 3, 6, and 12 months post-aHSCT and show that these cells increase early after aHSCT and decrease with time after aHSCT. DN T cells reside in the terminally differentiated effector (CD45RA(+)CCR7(-)) T-cell population and are polyclonal, determined by T-cell receptor Vβ CDR3 analysis.

Reduced plasma levels of soluble interleukin-7 receptor during graft-versus-host disease (GVHD) in children and adults.

Background: Interleukin 7 (IL-7) signals via the IL-7 receptor (IL-7R) and drives homeostatic T-cell proliferation in patients after allogeneic hematopoietic stem cell transplantation (aHSCT).

Purpose: We performed a prospective study in adults (n = 33) and children (n = 29) undergoing aHSCT measuring plasma IL-7 and soluble IL-7R (sIL-7R) concentrations between 1 and 12 months after HSCT in order to investigate the link between sIL-7R and clinical events after aHSCT.

Results: sIL-7R, but not IL-7, increased with time after HSCT in plasma from all patients enrolled in the study.

Humanized mice as a model for aberrant responses in human T cell immunotherapy.

Immune-deficient mice, reconstituted with human stem cells, have been used to analyze human immune responses in vivo. Although they have been used to study immune responses to xenografts, allografts, and pathogens, there have not been models of autoimmune disease in which the mechanisms of the pathologic process can be analyzed. We have found that reconstituted "humanized" mice treated with anti-CTLA-4 Ab (ipilimumab) develop autoimmune disease characterized by hepatitis, adrenalitis, sialitis, anti-nuclear Abs, and weight loss.

Delayed anti-CD3 therapy in a mouse heart transplant model induced tolerance and long-term survival of allograft: achieving tolerance.

Goto R, You S, Zaitsu M, Chatenoud L, Wood KJ. Delayed anti-CD3 therapy results in depletion of alloreactive T cells and the dominance of Foxp3(+) CD4(+) graft infiltrating cells. Am.

Reduced IL-7 responsiveness defined by signal transducer and activator of transcription 5 phosphorylation in T cells may be a marker for increased risk of developing cytomegalovirus disease in patients after hematopoietic stem cell transplantation.

Cytomegalovirus (CMV) reactivation may lead to CMV disease associated with high morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT); the identification of clinically relevant markers may aid in the identification of patients at increased risk for developing CMV-associated complications. We evaluated the phosphorylation of signal transducer and activator of transcription 5 (STAT5) in CD4(+) T cells, CD8(+) T cells, and TCRγδ T cells in response to stimulation with IL-7 or IL-2 after HSCT by analyzing blood samples taken monthly 1 to 6 months after HSCT. Patients were monitored weekly with a quantitative PCR from the time of engraftment for CMV viral load in whole blood until at least day 100 after HSCT.

Differential cellular recognition pattern to M. tuberculosis targets defined by IFN-γ and IL-17 production in blood from TB + patients from Honduras as compared to health care workers: TB and immune responses in patients from Honduras.

Background: A better understanding of the quality of cellular immune responses directed against molecularly defined targets will guide the development of TB diagnostics and identification of molecularly defined, clinically relevant M.tb vaccine candidates.

Methods: Recombinant proteins (n = 8) and peptide pools (n = 14) from M.

Dysregulation of CD4+CD25(high) T cells in the synovial fluid of patients with antibiotic-refractory Lyme arthritis.

Objective: To examine the role of immune dysregulation in antibiotic-refractory Lyme arthritis by comparing the phenotype, frequency, and function of CD4+ Teff cells and Treg cells in patients with antibiotic- responsive arthritis and patients with antibiotic-refractory arthritis.

Methods: Matched peripheral blood and synovial fluid samples from 15 patients with antibiotic-responsive arthritis were compared with those from 16 patients with antibiotic-refractory arthritis, using flow cytometry, suppression assays, and cytokine assays.

Results: Critical differences between the 2 patient groups were observed in the synovial fluid CD4+CD25(high) population, a cell subset usually composed of FoxP3-positive Treg cells.

Increased numbers of IL-7 receptor molecules on CD4+CD25-CD107a+ T-cells in patients with autoimmune diseases affecting the central nervous system.

Background: High content immune profiling in peripheral blood may reflect immune aberrations associated with inflammation in multiple sclerosis (MS) and other autoimmune diseases affecting the central nervous system.

Methods And Findings: Peripheral blood mononuclear cells from 46 patients with multiple sclerosis (MS), 9 patients diagnosed with relapsing remitting MS (RRMS), 13 with secondary progressive multiple sclerosis (SPMS), 9 with other neurological diseases (OND) and well as 15 healthy donors (HD) were analyzed by 12 color flow cytometry (TCRalphabeta, TCRgammadelta, CD4, CD8alpha, CD8beta, CD45RA, CCR7, CD27, CD28, CD107a, CD127, CD14) in a cross-sectional study to identify variables significantly different between controls (HD) and patients (OND, RRMS, SPMS). We analyzed 187 individual immune cell subsets (percentages) and the density of the IL-7 receptor alpha chain (CD127) on 59 individual immune phenotypes using a monoclonal anti-IL-7R antibody (clone R34.

Tumor antigen-specific T-cells are Present in the CD8alphaalpha+ T-cell effector-memory pool.

CD8+ T-cell memory formation has recently been demonstrated to be associated with CD8alphaalpha homodimer expression by T-cells in mice. Up to now, the knowledge about the clinical significance of CD8alphaalpha+ T-cells in humans is limited. We assessed in longitudinally collected blood samples from patients with melanoma, who underwent a peptide-based vaccination, the role of CD8alphaalpha+ T-cells in tumor-specific cellular immune responses.

Reduced numbers of IL-7 receptor (CD127) expressing immune cells and IL-7-signaling defects in peripheral blood from patients with breast cancer.

Interleukin-7-receptor-signaling plays a pivotal role in T-cell development and maintenance of T-cell memory. We studied IL-7Ralpha (CD127) expression in PBMCs obtained from patients with breast cancer and examined IL-7 receptor-mediated downstream effects defined by STAT5 phosphorylation (p-STAT5). Reduced numbers of IL-7Ralpha-positive cells were identified in CD4+ T-cells as well as in a CD8+ T-cell subset defined by CD8alpha/alpha homodimer expression in patients with breast cancer.

Direct evidence of endothelial injury during cardiopulmonary bypass by demonstration of circulating endothelial cells.

Endothelial activation is considered a key process in the development of a whole body inflammatory response secondary to cardiopulmonary bypass (CPB). Increased levels of a multitude of soluble mediators have been described as being released during and after cardiac surgery. Circulating endothelial cells have recently been established as a novel marker of endothelial damage in a variety of vascular disorders.

Reverse signalling of membrane-integrated tumour necrosis factor differentially regulates alloresponses of CD4+ and CD8+ T cells against human microvascular endothelial cells.

Reverse signalling of membrane-integrated ligands is a common phenomenon in the tumour necrosis factor (TNF) family and contributes to the pleiotropy of this pro-inflammatory cytokine and to the plasticity of the immune system in general. Transmembrane TNF (mTNF) itself can induce resistance to bacterial endotoxin in monocytes and can stimulate the immune activity of mitogen-activated, as well as of virus-infected, T cells. The aim of the present study was to investigate the influence of reverse signalling of mTNF on the allogeneic activity of CD4+ and CD8+ T cells against human microvascular endothelial cells (HMEC), as targets of various inflammatory responses.