44 research outputs found
Magnetic properties and concurrence for fluid 3He on kagome lattice
We present the results of magnetic properties and entanglement for kagome
lattice using Heisenberg model with two-, and three-site exchange interactions
in strong magnetic field. Kagome lattice correspond to the third layer of fluid
3He absorbed on the surface of graphite. The magnetic properties and
concurrence as a measure of pairwise thermal entanglement are studied by means
of variational mean-field like treatment based on Gibbs-Bogoliubov inequality.
The system exhibits different magnetic behaviors, depending on the values of
the exchange parameters (J2, J3). We have obtained the magnetization plateaus
at low temperatures. The central theme of the paper is the comparing the
entanglement and magnetic behavior for kagome lattice. We have found that in
the antiferromagnetic region behaviour of the concurrence coincides with the
magnetization one.Comment: Physics of Atomic Nuclei (accepted for publication) 201
Specific Class I HLA Supertypes but Not HLA Zygosity or Expression Are Associated with Outcomes following HLA-Matched Allogeneic Hematopoietic Cell Transplant: HLA Supertypes Impact Allogeneic HCT Outcomes
Maximizing the probability of antigen presentation to T cells through diversity in HLAs can enhance immune responsiveness and translate into improved clinical outcomes, as evidenced by the association of heterozygosity and supertypes at HLA class I loci with improved survival in patients with advanced solid tumors treated with immune checkpoint inhibitors. We investigated the impact of HLA heterozygosity, supertypes, and surface expression on outcomes in adult and pediatric patients with acute myeloid leukemia (AML), myelodysplastic syndrome, acute lymphoblastic leukemia, and non-Hodgkin lymphoma who underwent 8/8 HLA-matched, T cell replete, unrelated, allogeneic hematopoietic cell transplant (HCT) from 2000 to 2015 using patient data reported to the Center for International Blood and Marrow Transplant Research. HLA class I heterozygosity and HLA expression were not associated with overall survival, relapse, transplant-related mortality (TRM), disease-free survival (DFS), and acute graft-versus-host disease following HCT. The HLA-B62 supertype was associated with decreased TRM in the entire patient cohort (hazard ratio [HR], 0.79; 95% CI, 0.69 to 0.90; P = .00053). The HLA-B27 supertype was associated with worse DFS in patients with AML (HR = 1.21; 95% CI, 1.10 to 1.32; P = .00005). These findings suggest that the survival benefit of HLA heterozygosity seen in solid tumor patients receiving immune checkpoint inhibitors does not extend to patients undergoing allogeneic HCT. Certain HLA supertypes, however, are associated with TRM and DFS, suggesting that similarities in peptide presentation between supertype members play a role in these outcomes. Beyond implications for prognosis following HCT, these findings support the further investigation of these HLA supertypes and the specific immune peptides important for transplant outcomes
Low CD4+ T Cell Counts among African HIV-1 Infected Subjects with Group B KIR Haplotypes in the Absence of Specific Inhibitory KIR Ligands
Natural killer (NK) cells are regulated by interactions between polymorphic
killer immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA).
Genotypic combinations of KIR3DS1/L1 and HLA
Bw4-80I were previously shown to influence HIV-1 disease
progression, however other KIR genes have not been well
studied. In this study, we analyzed the influence of all activating and
inhibitory KIR, in association with the known HLA inhibitory KIR ligands, on
markers of disease progression in a West African population of
therapy-naïve HIV-1 infected subjects. We observed a significant
association between carriage of a group B KIR haplotype and
lower CD4+ T cell counts, with an additional effect for
KIR3DS1 within the frame of this haplotype. In contrast, we
found that individuals carrying genes for the inhibitory KIR ligands
HLA-Bw4 as well as HLA-C1 showed
significantly higher CD4+ T cell counts. These associations were
independent from the viral load and from individual HIV-1 protective HLA
alleles. Our data suggest that group B KIR haplotypes and lack
of specific inhibitory KIR ligand genes, genotypes considered to favor NK cell
activation, are predictive of HIV-1 disease progression