BackgroundThe role of reduced intensity conditioning allogeneic stem transplantation (RICalloSCT) in the management of patients with Hodgkin's lymphoma remains controversial. Design and MethodsTo further define its role we have conducted a retrospective analysis of 285 patients with HL who underwent a RICalloSCT in order to identify prognostic factors that predict outcome. Eighty percent of patients had undergone a prior autologous stem cell transplantation and 25% had refractory disease at transplant. ResultsNon-relapse mortality was associated with chemorefractory disease, poor performance status, age >45 and transplantation before 2002. For patients with no risk factors the 3-year non-relapse mortality rate was 12.5% compared to 46.2% for patients with 2 or more risk factors. The use of an unrelated donor had no adverse effect on the non-relapse mortality. Acute graft versus host disease (aGVHD) grades II-IV developed in 30% and chronic GVHD in 42%. The development of cGVHD was associated with a lower relapse rate. The disease progression rate at one and five years was 41% and 58.7% respectively and was associated with chemorefractory disease and extent of prior therapy. Donor lymphocyte infusions were administered to 64 patients for active disease of whom 32% showed a clinical response. Eight out of 18 patients receiving donor lymphocyte infusions alone had clinical responses. Progression-free and overall survival were both associated with performance status and disease status at transplant. Patients with neither risk factor had a 3-year PFS and overall survival of 42% and 56% respectively compared to 8% and 25% for patients with one or more risk factors. Relapse within six months of a prior autologous transplant was associated with a higher relapse rate and a lower progression-free. ConclusionsThis analysis identifies important clinical parameters that may be useful in predicting the outcome of RICaIICalloSCT in Hodgkin's lymphoma.Key words: Hodgkin's lymphoma, allogeneic transplantation, prognosis.Citation: Robinson SP, Sureda A, Canals C, Russell N, Caballero D, Bacigalupo A, Iriondo A, Cook G, Pettitt A, Socie G, Bonifazi F, Bosi A, Michallet M, Liakopoulou E, Maertens J, Passweg J, Clarke F, Martino R, and

ObjectiveTo investigate whether antidrug antibodies and/or drug non‐trough levels predict the long‐term treatment response in a large cohort of patients with rheumatoid arthritis (RA) treated with adalimumab or etanercept and to identify factors influencing antidrug antibody and drug levels to optimize future treatment decisions.MethodsA total of 331 patients from an observational prospective cohort were selected (160 patients treated with adalimumab and 171 treated with etanercept). Antidrug antibody levels were measured by radioimmunoassay, and drug levels were measured by enzyme‐linked immunosorbent assay in 835 serial serum samples obtained 3, 6, and 12 months after initiation of therapy. The association between antidrug antibodies and drug non‐trough levels and the treatment response (change in the Disease Activity Score in 28 joints) was evaluated.ResultsAmong patients who completed 12 months of followup, antidrug antibodies were detected in 24.8% of those receiving adalimumab (31 of 125) and in none of those receiving etanercept. At 3 months, antidrug antibody formation and low adalimumab levels were significant predictors of no response according to the European League Against Rheumatism (EULAR) criteria at 12 months (area under the receiver operating characteristic curve 0.71 [95% confidence interval (95% CI) 0.57, 0.85]). Antidrug antibody–positive patients received lower median dosages of methotrexate compared with antidrug antibody–negative patients (15 mg/week versus 20 mg/week; P = 0.01) and had a longer disease duration (14.0 versus 7.7 years; P = 0.03). The adalimumab level was the best predictor of change in the DAS28 at 12 months, after adjustment for confounders (regression coefficient 0.060 [95% CI 0.015, 0.10], P = 0.009). Etanercept levels were associated with the EULAR response at 12 months (regression coefficient 0.088 [95% CI 0.019, 0.16], P = 0.012); however, this difference was not significant after adjustment. A body mass index of ≥30 kg/m2 and poor adherence were associated with lower drug levels.ConclusionPharmacologic testing in anti–tumor necrosis factor–treated patients is clinically useful even in the absence of trough levels. At 3 months, antidrug antibodies and low adalimumab levels are significant predictors of no response according to the EULAR criteria at 12 months.

Dendritic cells (DCs) are professional APCs that reside in peripheral tissues and survey the body for pathogens. Upon activation by inflammatory signals, DCs undergo a maturation process and migrate to lymphoid organs, where they present pathogen-derived Ags to T cells. DC migration depends on tight regulation of the actin cytoskeleton to permit rapid adaptation to environmental cues. We investigated the role of hematopoietic lineage cell-specific protein 1 (HS1), the hematopoietic homolog of cortactin, in regulating the actin cytoskeleton of murine DCs. HS1 localized to lamellipodial protrusions and podosomes, actin-rich structures associated with adhesion and migration. DCs from HS1−/− mice showed aberrant lamellipodial dynamics. Moreover, although these cells formed recognizable podosomes, their podosome arrays were loosely packed and improperly localized within the cell. HS1 interacts with Wiskott-Aldrich Syndrome protein (WASp), another key actin-regulatory protein, through mutual binding to WASp-interacting protein. Comparative analysis of DCs deficient for HS1, WASp or both proteins revealed unique roles for these proteins in regulating podosomes with WASp being essential for podosome formation and with HS1 ensuring efficient array organization. WASp recruitment to podosome cores was independent of HS1, whereas HS1 recruitment required Src homology 3 domain-dependent interactions with the WASp/WASp-interacting protein heterodimer. In migration assays, the phenotypes of HS1- and WASp-deficient DCs were related, but distinct. WASp−/y DCs migrating in a chemokine gradient showed a large decrease in velocity and diminished directional persistence. In contrast, HS1−/− DCs migrated faster than wild-type cells, but directional persistence was significantly reduced. These studies show that HS1 functions in concert with WASp to fine-tune DC cytoarchitecture and direct cell migration.

T cell uropods are enriched in specific proteins including adhesion receptors such as P-selectin glycoprotein ligand-1 (PSGL-1), lipid raft-associated proteins such as flotillins and ezrin/radixin/moesin (ERM) proteins which associate with cholesterol-rich raft domains and anchor adhesion receptors to the actin cytoskeleton. Using dominant mutants and siRNA technology we have tested the interactions among these proteins and their role in shaping the T cell uropod. Expression of wild type (WT) ezrin-EGFP failed to affect the morphology of human T cells or chemokine-induced uropod recruitment of PSGL-1 and flotillin-1 and -2. In contrast, expression of constitutively active T567D ezrin-EGFP induced a motile, polarized phenotype in some of the transfected T cells, even in the absence of chemokine. These cells featured F-actin-rich ruffles in the front and uropod enrichment of PSGL-1 and flotillins. T567D ezrin-EGFP was itself strongly enriched in the rear of the polarized T cells. Uropod formation induced by T567D ezrin-EGFP was actin-dependent as it was attenuated by inhibition of Rho-kinase or myosin II, and abolished by disruption of actin filaments. While expression of constitutively active ezrin enhanced cell polarity, expression of a dominant-negative deletion mutant of ezrin, 1–310 ezrin-EGFP, markedly reduced uropod formation induced by the chemokine SDF-1, T cell front-tail polarity, and capping of PSGL-1 and flotillins. Transfection of T cells with WT or T567D ezrin did not affect chemokine-mediated chemotaxis whereas 1–310 ezrin significantly impaired spontaneous 2D migration and chemotaxis. siRNA-mediated downregulation of flotillins in murine T cells attenuated moesin capping and uropod formation, indicating that ERM proteins and flotillins cooperate in uropod formation. In summary, our results indicate that activated ERM proteins function together with flotillins to promote efficient chemotaxis of T cells by structuring the uropod of migrating T cells.

R e s e a R c h a R t i c l e1 0 2 0 jci.org Volume 125 Number 3 March 2015 therapeutic implications, since they can carry out graftversus-leukemia (GVL) responses with minimal GVHD. Results Generation and characterization of T cell-specific CRK T cells (data not shown).Western blotting of purified CD4 + T cells from Dko and WT mice revealed that levels of CRKI, CRKII, and CRKL in the mutant T cells were reduced by at least 95% ( Figure 1A and data not shown), and flow cytometric analysis confirmed loss of CRK protein expression (Figure 1, B and C).CRK/CRKL Dko mice were born at Mendelian ratios, and spleen, thymus, and lymph nodes exhibited normal cellularity (data not shown). Thymocyte populations were similar in WT and Dko mice, indicating that T cell development proceeded normally ( Figure 1D). Peripheral lymphoid organs showed no differences in proportions of CD4 + and CD8 + T cells, naive (CD62L hi CD44 lo ), memory (CD62L lo CD44 hi ), or activated (CD69 hi ) T cell subsets (Figure 1, D and E, and data not shown). Thus, these mice represented a suitable source of mature CRK/CRKL Dko T cells for functional studies. CRK/CRKL-deficient T cells show defects in adhesion and polarization.Since CRK proteins control adhesion in non-hematopoietic cells (4), we first asked whether integrin-dependent adhesion is defective in CRK/CRKL Dko T cells. On plates coated with ICAM-1, the ligand for the β 2 integrin LFA-1, WT preactivated CD4 + T cells showed about 10% basal binding, which was increased 2-to 5-fold after stimulation with the chemokines CXCL12 or CCL21, or anti-CD3 (Figure 2A). CRK/CRKL Dko T cells showed a significant reduction in adhesion to ICAM-1 under both basal and stimulated conditions. Indeed, chemokine stimulation induced almost no increased adhesion in these cells. Treatment with PMA bypassed the defect. This is most likely because the defect in CRK/CRKL Dko cells lies upstream of PKC signaling in the pathway leading to integrin activation, though PKC activation could also drive a parallel

Abstract:Integrins are transmembrane heterodimers that play a fundamental role in the migration of leukocytes to sites of infection or injury. Here, we provide evidence that the protein tyrosine phosphatase PTPN22 is a novel regulator of LFA-1 signaling in effector T-cells.PTPN22 co-localizes with its substrates at the leading edge of cells migrating on ICAM-1. Gene targeting, or expression of the autoimmune disease-associated PTPN22-R620W variant, results in hyper-phosphorylation of integrin signaling intermediates. Super-resolution imaging reveals that in the steady state PTPN22-R620 exists in large clusters that disaggregate upon LFA-1 stimulation, permitting increased association with its binding partners at the membrane. Failure to retain PTPN22-R620W molecules at the membrane leads to increased LFA-1 clustering and integrin-mediated cell adhesion. Our data define a novel mechanism for fine-tuning integrin signaling in T-cells, and a new paradigm of autoimmunity in man in which disease susceptibility is underpinned by inherited perturbations of integrin function.One Sentence Summary: PTPN22 is a negative regulator of integrin signaling and loss-offunction mutants increase cell adhesion.3

T cell receptor (TCR) engagement induces clustering and recruitment to the plasma membrane of many signaling molecules, including the protein tyrosine kinase zeta-chain associated protein of 70 kDa (ZAP70) and the adaptor SH2 domain-containing leukocyte protein of 76 kDa (SLP76). This molecular rearrangement results in formation of the immunological synapse (IS), a dynamic protein array that modulates T cell activation. The current study investigates the effects of apparent long-range ligand mobility on T cell signaling activity and IS formation. We formed stimulatory lipid bilayers on glass surfaces from binary lipid mixtures with varied composition, and characterized these surfaces with respect to diffusion coefficient and fluid connectivity. Stimulatory ligands coupled to these surfaces with similar density and orientation showed differences in their ability to activate T cells. On less mobile membranes, central supramolecular activation cluster (cSMAC) formation was delayed and the overall accumulation of CD3ζ at the IS was reduced. Analysis of signaling microcluster (MC) dynamics showed that ZAP70 MCs exhibited faster track velocity and longer trajectories as a function of increased ligand mobility, whereas movement of SLP76 MCs was relatively insensitive to this parameter. Actin retrograde flow was observed on all surfaces, but cell spreading and subsequent cytoskeletal contraction were more pronounced on mobile membranes. Finally, increased tyrosine phosphorylation and persistent elevation of intracellular Ca2+ were observed in cells stimulated on fluid membranes. These results point to ligand mobility as an important parameter in modulating T cell responses.

Tris(hydroxypyridinone) chelators conjugated to peptides can rapidly complex the positron-emitting isotope gallium-68 (68Ga) under mild conditions, and the resulting radiotracers can delineate peptide receptor expression at sites of diseased tissue in vivo. We have synthesized a dendritic bifunctional chelator containing nine 1,6-dimethyl-3-hydroxypyridin-4-one groups (SCN-HP9) that can coordinate up to three Ga3+ ions. This derivative has been conjugated to a trimeric peptide (RGD3) containing three peptide groups that target the αvβ3 integrin receptor. The resulting dendritic compound, HP9-RGD3, can be radiolabeled in 97% radiochemical yield at a 3-fold higher specific activity than its homologues HP3-RGD and HP3-RGD3 that contain only a single metal binding site. PET scanning and biodistribution studies show that [68Ga(HP9-RGD3)] demonstrates higher receptor-mediated tumor uptake in animals bearing U87MG tumors that overexpress αvβ3 integrin than [68Ga(HP3-RGD)] and [68Ga(HP3-RGD3)]. However, concomitant nontarget organ retention of [68Ga(HP9-RGD3)] results in low tumor to nontarget organ contrast in PET images. On the other hand, the trimeric peptide homologue containing a single tris(hydroxypyridinone) chelator, [68Ga(HP3-RGD3)], clears nontarget organs and exhibits receptor-mediated uptake in mice bearing tumors and in mice with induced rheumatoid arthritis. PET imaging with [68Ga(HP3-RGD3)] enables clear delineation of αvβ3 integrin receptor expression in vivo.