Lymph Node-Targeted Vaccine Boosting of TCR T-cell Therapy Enhances Antitumor Function and Eradicates Solid Tumors

T-cell receptor (TCR)-modified T-cell therapies have shown promise against solid tumors, but overall therapeutic benefits have been modest due in part to suboptimal T-cell persistence and activation in vivo, alongside potential tumor antigen escape. In this study, we demonstrate an approach to enhance the in vivo persistence and function of TCR T cells through combination with Amphiphile (AMP) vaccination including cognate TCR T peptides. AMP modification improves lymph node targeting of conjugated tumor immunogens and adjuvants, thereby coordinating a robust T cell-activating endogenous immune response. AMP vaccine combination with TCR T-cell therapy led to complete eradication and durable responses against established murine solid tumors refractory to TCR T-cell monotherapy. Enhanced antitumor efficacy was correlated with simultaneous in vivo invigoration of adoptively transferred TCR T cells and in situ expansion of the endogenous antitumor T-cell repertoire. Long-term protection against tumor recurrence in AMP-vaccinated mice was associated with antigen spreading to additional tumor-associated antigens not targeted by vaccination. AMP vaccination further correlated with pro-inflammatory lymph node transcriptional reprogramming and increased antigen presenting-cell maturation, resulting in TCR T-cell expansion and functional enhancement in lymph nodes and solid tumor parenchyma without lymphodepletion. In vitro evaluation of AMP peptides with matched human TCR T cells targeting NY-ESO-1, mutant KRAS, and HPV16 E7 illustrated the clinical potential of AMP vaccination to enhance human TCR T-cell proliferation, activation, and antitumor activity. Taken together, these studies provide rationale and evidence to support clinical evaluation of combining AMP vaccination with TCR T-cell therapies to augment antitumor activity.

Lymph node targeted multi-epitope subunit vaccine promotes effective immunity to EBV in HLA-expressing mice

The recent emergence of a causal link between Epstein-Barr virus (EBV) and multiple sclerosis has generated considerable interest in the development of an effective vaccine against EBV. Here we describe a vaccine formulation based on a lymph node targeting Amphiphile vaccine adjuvant, Amphiphile-CpG, admixed with EBV gp350 glycoprotein and an engineered EBV polyepitope protein that includes 20 CD8+ T cell epitopes from EBV latent and lytic antigens. Potent gp350-specific IgG responses are induced in mice with titers >100,000 in Amphiphile-CpG vaccinated mice. Immunization including Amphiphile-CpG also induces high frequencies of polyfunctional gp350-specific CD4+ T cells and EBV-specific CD8+ T cells that are 2-fold greater than soluble CpG and are maintained for >7 months post immunization. This combination of broad humoral and cellular immunity against multiple viral determinants is likely to provide better protection against primary infection and control of latently infected B cells leading to protection against the development of EBV-associated diseases.

Amphiphile-CpG vaccination induces potent lymph node activation and COVID-19 immunity in mice and non-human primates

Despite the success of currently authorized vaccines for the reduction of severe COVID-19 disease risk, rapidly emerging viral variants continue to drive pandemic waves of infection, resulting in numerous global public health challenges. Progress will depend on future advances in prophylactic vaccine activity, including advancement of candidates capable of generating more potent induction of cross-reactive T cells and durable cross-reactive antibody responses. Here we evaluated an Amphiphile (AMP) adjuvant, AMP-CpG, admixed with SARS-CoV-2 Spike receptor binding domain (RBD) immunogen, as a lymph node-targeted protein subunit vaccine (ELI-005) in mice and non-human primates (NHPs). AMP-mediated targeting of CpG DNA to draining lymph nodes resulted in comprehensive local immune activation characterized by extensive transcriptional reprogramming, inflammatory proteomic milieu, and activation of innate immune cells as key orchestrators of antigen-directed adaptive immunity. Prime-boost immunization with AMP-CpG in mice induced potent and durable T cell responses in multiple anatomical sites critical for prophylactic efficacy and prevention of severe disease. Long-lived memory responses were rapidly expanded upon re-exposure to antigen. In parallel, RBD-specific antibodies were long-lived, and exhibited cross-reactive recognition of variant RBD. AMP-CpG-adjuvanted prime-boost immunization in NHPs was safe and well tolerated, while promoting multi-cytokine-producing circulating T cell responses cross-reactive across variants of concern (VOC). Expansion of RBD-specific germinal center (GC) B cells in lymph nodes correlated to rapid seroconversion with variant-specific neutralizing antibody responses exceeding those measured in convalescent human plasma. These results demonstrate the promise of lymph-node adjuvant-targeting to coordinate innate immunity and generate robust adaptive responses critical for vaccine efficacy.

A lymph node-targeted Amphiphile vaccine induces potent cellular and humoral immunity to SARS-CoV-2

The profound consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mandate urgent development of effective vaccines. Here, we evaluated an Amphiphile (AMP) vaccine adjuvant, AMP-CpG, composed of diacyl lipid-modified CpG, admixed with the SARS-CoV-2 Spike-2 receptor binding domain protein as a candidate vaccine (ELI-005) in mice. AMP modification efficiently delivers CpG to lymph nodes, where innate and adaptive immune responses are generated. Compared to alum, immunization with AMP-CpG induced >25-fold higher antigen-specific T cells that produced multiple T helper 1 (T_H1) cytokines and trafficked into lung parenchyma. Antibody responses favored T_H1 isotypes (IgG2c and IgG3) and potently neutralized Spike-2-ACE2 receptor binding, with titers 265-fold higher than natural convalescent patient COVID-19 responses; T cell and antibody responses were maintained despite 10-fold dose reduction in Spike antigen. Both cellular and humoral immune responses were preserved in aged mice. These advantages merit clinical translation to SARS-CoV-2 and other protein subunit vaccines.

Antibody-mediated targeting of TNFR2 activates CD8+ T cells in mice and promotes antitumor immunity

Tumor necrosis factor receptor 2 (TNFR2) is the alternate receptor for TNF and can mediate both pro- and anti-inflammatory activities of T cells. Although TNFR2 has been linked to enhanced suppressive activity of regulatory T cells (Tregs) in autoimmune diseases, the viability of TNFR2 as a target for cancer immunotherapy has been underappreciated. Here, we show that new murine monoclonal anti-TNFR2 antibodies yield robust antitumor activity and durable protective memory in multiple mouse cancer cell line models. The antibodies mediate potent Fc-dependent T cell costimulation and do not result in significant depletion of Tregs. Corresponding human agonistic monoclonal anti-TNFR2 antibodies were identified and also had antitumor effects in humanized mouse models. Anti-TNFR2 antibodies could be developed as a novel treatment option for patients with cancer.

Prospective assessment of white matter integrity in adult stem cell transplant recipients

Hematopoietic stem cell transplantation (HSCT) is often used in the treatment of hematologic disorders. Although it can be curative, the pre-transplant conditioning regimen can be associated with neurotoxicity. In this prospective study, we examined white matter (WM) integrity with diffusion tensor imaging (DTI) and neuropsychological functioning before and one year after HSCT in twenty-two patients with hematologic disorders and ten healthy controls evaluated at similar intervals. Eighteen patients received conditioning treatment with high-dose (HD) chemotherapy, and four had full dose total body irradiation (fTBI) and HD chemotherapy prior to undergoing an allogeneic or autologous HSCT. The results showed a significant decrease in mean diffusivity (MD) and axial diffusivity (AD) in diffuse WM regions one year after HSCT (p-corrected <0.05) in the patient group compared to healthy controls. At baseline, patients treated with allogeneic HSCT had higher MD and AD in the left hemisphere WM than autologous HSCT patients (p-corrected <0.05). One year post-transplant, patients treated with allogeneic HSCT had lower fractional anisotropy (FA) and higher radial diffusivity (RD) in the right hemisphere and left frontal WM compared to patients treated with autologous HSCT (p-corrected <0.05).There were modest but significant correlations between MD values and cognitive test scores, and these were greatest for timed tests and in projection tracts. Patients showed a trend toward a decline in working memory, and had lower cognitive test scores than healthy controls at the one-year assessment. The findings suggest a relatively diffuse pattern of alterations in WM integrity in adult survivors of HSCT.

A prospective evaluation of changes in brain structure and cognitive functions in adult stem cell transplant recipients

Hematopoietic stem cell transplantation (HSCT) is an efficacious treatment for many hematologic malignancies. However, the conditioning regimen of high-dose (HD) chemotherapy with or without total body irradiation (TBI) can be associated with neurotoxicity. In this prospective study, we used quantitative neuroimaging techniques to examine regional gray matter and ventricular volumes, and standardized neuropsychological tests to assess cognitive function before and 1 year after HSCT in 28 patients with hematologic malignancies and in ten healthy controls evaluated at similar intervals. Nineteen patients received conditioning treatment with HD chemotherapy alone and nine had both TBI and HD chemotherapy. There was a significant reduction in gray matter volume in the middle frontal gyrus bilaterally and in the left caudate nucleus in the patient group (all patients combined) but not among healthy controls over the 1-year follow-up period. There was a significant increase in left lateral ventricle volume and in total ventricle volume in the patient group, relative to healthy controls. Similar brain structural changes were seen for patients treated with HD chemotherapy alone. The neuropsychological results showed that 21% of patients could be classified as impaired at baseline. The Reliable Change Index suggested no significantly different rates of cognitive decline between patients and healthy controls. The findings suggest that HSCT patients may be at an increased risk for developing regional brain volume loss, and that subgroups may experience cognitive dysfunction prior to and 1 year following the transplant.

Graft-versus-host disease after double-unit cord blood transplantation has unique features and an association with engrafting unit-to-recipient HLA match

Manifestations of and risk factors for graft-versus-host disease (GVHD) after double-unit cord blood transplantation (DCBT) are not firmly established. We evaluated 115 DCBT recipients (median age, 37 years) who underwent transplantation for hematologic malignancies with myeloablative or nonmyeloablative conditioning and calcineurin inhibitor/mycophenolate mofetil immunosuppression. Incidence of day 180 grades II to IV and III to IV acute GVHD (aGVHD) were 53% (95% confidence interval, 44 to 62) and 23% (95% confidence interval, 15 to 31), respectively, with a median onset of 40 days (range, 14 to 169). Eighty percent of patients with grades II to IV aGVHD had gut involvement, and 79% and 85% had day 28 treatment responses to systemic corticosteroids or budesonide, respectively. Of 89 engrafted patients cancer-free at day 100, 54% subsequently had active GVHD, with 79% of those affected having persistent or recurrent aGVHD or overlap syndrome. Late GVHD in the form of classic chronic GVHD was uncommon. Notably, grades III to IV aGVHD incidence was lower if the engrafting unit human leukocyte antigen (HLA)-A, -B, -DRB1 allele match was >4/6 to the recipient (hazard ratio, 0.385; P = .031), whereas engrafting unit infused nucleated cell dose and unit-to-unit HLA match were not significant. GVHD after DCBT was common in our study, predominantly affected the gut, and had a high therapy response, and late GVHD frequently had acute features. Our findings support the consideration of HLA- A,-B,-DRB1 allele donor-recipient (but not unit-unit) HLA match in unit selection, a practice change in the field. Moreover, new prophylaxis strategies that target the gastrointestinal tract are needed.

Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R&D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R&D.

The inflammatory cytokines TWEAK and TNFα reduce renal klotho expression through NFκB

Proinflammatory cytokines contribute to renal injury, but the downstream effectors within kidney cells are not well understood. One candidate effector is Klotho, a protein expressed by renal cells that has antiaging properties; Klotho-deficient mice have an accelerated aging-like phenotype, including vascular injury and renal injury. Whether proinflammatory cytokines, such as TNF and TNF-like weak inducer of apoptosis (TWEAK), modulate Klotho is unknown. In mice, exogenous administration of TWEAK decreased expression of Klotho in the kidney. In the setting of acute kidney injury induced by folic acid, the blockade or absence of TWEAK abrogated the injury-related decrease in renal and plasma Klotho levels. TWEAK, TNFα, and siRNA-mediated knockdown of IκBα all activated NFκB and reduced Klotho expression in the MCT tubular cell line. Furthermore, inhibition of NFκB with parthenolide prevented TWEAK- or TNFα-induced downregulation of Klotho. Inhibition of histone deacetylase reversed TWEAK-induced downregulation of Klotho, and chromatin immunoprecipitation showed that TWEAK promotes RelA binding to the Klotho promoter, inducing its deacetylation. In conclusion, inflammatory cytokines, such as TWEAK and TNFα, downregulate Klotho expression through an NFκB-dependent mechanism. These results may partially explain the relationship between inflammation and diseases characterized by accelerated aging of organs, including CKD.

Tumor necrosis factor-like weak inducer of apoptosis is a mitogen for liver progenitor cells

Liver progenitor cells (LPCs) represent the cell compartment facilitating hepatic regeneration during chronic injury while hepatocyte-mediated repair mechanisms are compromised. LPC proliferation is frequently observed in human chronic liver diseases such as hereditary hemochromatosis, fatty liver disease, and chronic hepatitis. In vivo studies have suggested that a tumor necrosis factor family member, tumor necrosis factor-like weak inducer of apoptosis (TWEAK), is promitotic for LPCs; whether it acts directly is not known. In our murine choline-deficient, ethionine-supplemented (CDE) model of chronic liver injury, TWEAK receptor [fibroblast growth factor-inducible 14 (Fn14)] expression in the whole liver is massively upregulated. We therefore set out to investigate whether TWEAK/Fn14 signaling promotes the regenerative response in CDE-induced chronic liver injury by mitotic stimulation of LPCs. Fn14 knockout (KO) mice showed significantly reduced LPC numbers and attenuated inflammation and cytokine production after 2 weeks of CDE feeding. The close association between LPC proliferation and activation of hepatic stellate cells in chronic liver injury prompted us to investigate whether fibrogenesis was also modulated in Fn14 KO animals. Collagen deposition and expression of key fibrogenesis mediators were reduced after 2 weeks of injury, and this correlated with LPC numbers. Furthermore, the injection of 2-week-CDE-treated wildtype animals with TWEAK led to increased proliferation of nonparenchymal pan cytokeratin-positive cells. Stimulation of an Fn14-positive LPC line with TWEAK led to nuclear factor kappa light chain enhancer of activated B cells (NFkappaB) activation and dose-dependent proliferation, which was diminished after targeting of the p50 NFkappaB subunit by RNA interference.

CONCLUSION

TWEAK acts directly and stimulates LPC mitosis in an Fn14-dependent and NFkappaB-dependent fashion, and signaling via this pathway mediates the LPC response to CDE-induced injury and regeneration.

TWEAK activates the non-canonical NFkappaB pathway in murine renal tubular cells: modulation of CCL21

TWEAK is a member of the TNF superfamily of cytokines that contribute to kidney tubulointerstitial injury. It has previously been reported that TWEAK induces transient nuclear translocation of RelA and expression of RelA-dependent cytokines in renal tubular cells. Additionally, TWEAK induced long-lasting NFκB activation suggestive of engagement of the non-canonical NFκB pathway. We now explore TWEAK-induced activation of NFκB2 and RelB, as well as expression of CCL21, a T-cell chemotactic factor, in cultured murine tubular epithelial cells and in healthy kidneys in vivo. In cultured tubular cells, TWEAK and TNFα activated different DNA-binding NFκB complexes. TWEAK-induced sustained NFκB activation was associated with NFκB2 p100 processing to p52 via proteasome and nuclear translocation and DNA-binding of p52 and RelB. TWEAK, but not TNFα used as control), induced a delayed increase in CCL21a mRNA (3.5±1.22-fold over control) and CCL21 protein (2.5±0.8-fold over control), which was prevented by inhibition of the proteasome, or siRNA targeting of NIK or RelB, but not by RelA inhibition with parthenolide. A second NFκB2-dependent chemokine, CCL19, was upregulates by TWEAK, but not by TNFα. However, both cytokines promoted chemokine RANTES expression (3-fold mRNA at 24 h). In vivo, TWEAK induced nuclear NFκB2 and RelB translocation and CCL21a mRNA (1.5±0.3-fold over control) and CCL21 protein (1.6±0.5-fold over control) expression in normal kidney. Increased tubular nuclear RelB and tubular CCL21 expression in acute kidney injury were decreased by neutralization (2±0.9 vs 1.3±0.6-fold over healthy control) or deficiency of TWEAK (2±0.9 vs 0.8±0.6-fold over healthy control). Moreover, anti-TWEAK treatment prevented the recruitment of T cells to the kidney in this model (4.1±1.4 vs 1.8±1-fold over healthy control). Our results thus identify TWEAK as a regulator of non-canonical NFκB activation and CCL21 expression in tubular cells thus promoting lymphocyte recruitment to the kidney during acute injury.

Tumor Necrosis Factor–Like Weak Inducer of Apoptosis (TWEAK) Enhances Vascular and Renal Damage Induced by Hyperlipidemic Diet in ApoE-Knockout Mice

Objective— Tumor necrosis factor–like weak inducer of apoptosis (TWEAK) is a member of the tumor necrosis factor superfamily of cytokines. TWEAK binds and activates the Fn14 receptor, and may regulate apoptosis, inflammation, and angiogenesis, in different pathological conditions. We have evaluated the effect of exogenous TWEAK administration as well as the role of endogenous TWEAK on proinflammatory cytokine expression and vascular and renal injury severity in hyperlipidemic ApoE-knockout mice.

Methods and Results— ApoE −/− mice were fed with hyperlipidemic diet for 4 to 10 weeks, then randomized and treated with saline (controls), TWEAK (10 μg/kg/d), anti-TWEAK neutralizing mAb (1000 μg/kg/d), TWEAK plus anti-TWEAK antibody (10 μg TWEAK +1000 μg anti-TWEAK/kg/d), or nonspecific IgG (1000 μg/kg/d) daily for 9 days. In ApoE −/− mice, exogenous TWEAK administration in ApoE −/− mice induced activation of NF-κB, a key transcription factor implicated in the regulation of the inflammatory response, in vascular and renal lesions. Furthermore, TWEAK treatment increased chemokine expression (RANTES and MCP-1), as well as macrophage infiltration in atherosclerotic plaques and renal lesions. These effects were associated with exacerbation of vascular and renal damage. Conversely, treatment of ApoE −/− mice with an anti-TWEAK blocking mAb decreased NF-κB activation, proinflammatory cytokine expression, macrophage infiltration, and vascular and renal injury severity, indicating a pathological role for endogenous TWEAK. Finally, in murine vascular smooth muscle cells or tubular cells, either ox-LDL or TWEAK treatment increased expression and secretion of both RANTES and MCP-1. Furthermore, ox-LDL and TWEAK synergized for induction of MCP-1 and RANTES expression and secretion.

Conclusion— Our results suggest that TWEAK exacerbates the inflammatory response associated with a high lipid–rich diet. TWEAK may be a novel therapeutic target to prevent vascular and renal damage associated with hyperlipidemia.

Hepatic safety of voriconazole after allogeneic hematopoietic stem cell transplantation

Voriconazole is increasingly used in allogeneic hematopoietic stem cell transplantation (HSCT) for prophylaxis and treatment of fungal infections. Hepatic dysfunction is common in patients undergoing HSCT and may have an impact on the clinical decision to institute voriconazole. We conducted a retrospective review of all adult and pediatric HSCT recipients who received >2 consecutive doses of voriconazole between January 2005 and February 2008. Clinical hepatotoxicity was defined as the subjective attribution of liver enzyme elevation (even a mild one) to hepatotoxicity because of voriconazole by the treating physician and leading to discontinuation of voriconazole. Biochemical hepatotoxicity was defined as an elevation in one or more liver enzymes to >3 times the upper limit of normal or >3 times the baseline value if abnormal at baseline. Liver enzymes assessed included aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total bilirubin. Simple and multiple logistic regressions were used to define the risks for hepatic dysfunction. The Wilcoxon signed-rank test was used to assess the differences in liver function test values before, during, and after the use of voriconazole. Sixty-eight of 200 patients (34%) developed hepatotoxicity while on voriconazole. The median duration of voriconazole therapy was 72 days (range, 1-804 days). Biochemical hepatotoxicity occurred in 51 patients (75%); clinical hepatotoxicity, in 17 patients (25%). Thirty-five (51%) of the patients with hepatotoxicity required discontinuation of therapy. In simple logistic regression, acute graft-versus-host disease (GVHD) was a risk factor for hepatotoxicity, and receipt of a T-cell depleted allograft was protective. In multiple logistic regression, acute GVHD (P = .002) remained significant. There were no cases of liver failure or death attributed to voriconazole. In this cohort of patients undergoing allogeneic HSCT, the rate of hepatotoxicity while on voriconazole was 34%. In general, the hepatic dysfunction was mild and reversible. Voriconazole therapy with monitoring appears to be reasonably safe for use in HSCT recipients at high risk for invasive fungal infections.

Tweak induces proliferation in renal tubular epithelium: a role in uninephrectomy induced renal hyperplasia

The tumour necrosis factor (TNF) family member TWEAK activates the Fn14 receptor and has pro-apoptotic, proliferative and pro-inflammatory actions that depend on the cell type and the microenvironment. We explored the proliferative actions of TWEAK on cultured tubular cells and in vivo on renal tubules. Additionally, we studied the role of TWEAK in compensatory proliferation following unilateral nephrectomy and in an inflammatory model of acute kidney injury (AKI) induced by a folic acid overdose. TWEAK increased the proliferation, cell number and cyclin D1 expression of cultured tubular cells, in vitro. Exposure to serum increased TWEAK and Fn14 expression and the proliferative response to TWEAK. TWEAK activated the mitogen-activated protein kinases ERK and p38, the phosphatidyl-inositol 3-kinase (PI3K)/Akt pathway and NF-κB. TWEAK-induced proliferation was prevented by inhibitors of these protein kinases and by the NF-κB inhibitor parthenolide. TWEAK-induced tubular cell proliferation as assessed by PCNA and cyclin D1 expression in the kidneys of adult healthy mice in vivo. By contrast, TWEAK knock-out mice displayed lower tubular cell proliferation in the remnant kidney following unilateral nephrectomy, a non-inflammatory model. This is consistent with TWEAK-induced proliferation on cultured tubular cells in the absence of inflammatory cytokines. Consistent with our previously published data, in the presence of inflammatory cytokines TWEAK promoted apoptosis, not proliferation, of cultured tubular cells. In this regard, TWEAK knock-out mice with AKI displayed less tubular apoptosis and proliferation, as well as improved renal function. In conclusion, TWEAK actions in tubular cells are context dependent. In a non-inflammatory milieu TWEAK induces proliferation of tubular epithelium. This may be relevant for compensatory renal hyperplasia following nephrectomy.

A novel role for tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in the development of cardiac dysfunction and failure

BACKGROUND

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, is a multifunctional cytokine known to regulate cellular functions in contexts of injury and disease through its receptor, fibroblast growth factor-inducible molecule 14 (Fn14). Although many of the processes and downstream signals regulated by the TWEAK/Fn14 pathway have been implicated in the development of cardiac dysfunction, the role of TWEAK in the cardiovascular system is completely unknown.

METHODS AND RESULTS

Herein, we demonstrate that mouse and human cardiomyocytes express the TWEAK receptor Fn14. Furthermore, we determine that elevated circulating levels of TWEAK, induced via transgenic or adenoviral-mediated gene expression in mice, result in dilated cardiomyopathy with subsequent severe cardiac dysfunction. This phenotype was mediated exclusively by the Fn14 receptor, independent of tumor necrosis factor-alpha, and was associated with cardiomyocyte elongation and cardiac fibrosis but not cardiomyocyte apoptosis. Moreover, we find that circulating TWEAK levels were differentially upregulated in patients with idiopathic dilated cardiomyopathy compared with other forms of heart disease and normal control subjects.

CONCLUSIONS

Our data suggest that TWEAK/Fn14 may be important in regulating myocardial structural remodeling and function and may play a role in the pathogenesis of dilated cardiomyopathy.

TWEAK/Fn14 pathway: a nonredundant role in intestinal damage in mice through a TWEAK/intestinal epithelial cell axis

BACKGROUND AND AIMS

Tumor necrosis factor (TNF) superfamily members have attracted attention as new therapeutic targets for treating inflammatory disease. TNF-like weak inducer of apoptosis (TWEAK) is a unique, multifunctional TNF family cytokine that signals through its receptor, fibroblast growth factor-inducible molecule 14 (Fn14). The role of this pathway in the intestine has not been previously reported.

METHODS

The 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model was conducted in TWEAK- or Fn14-deficient mice or in normal mice treated with a TWEAK-blocking monoclonal antibody, and clinical severity, histopathology, immunohistochemistry for cell infiltrates, TWEAK and Fn14, gene expression profiling in the colon, and systemic adaptive immunity were assessed. The effect of TWEAK on colon epithelial cell production of inflammatory mediators was analyzed in vitro. The gamma-irradiation injury model was conducted in TWEAK- or Fn14-deficient mice, and crypt epithelial death was assessed.

RESULTS

Colitis severity and histologic scores were significantly reduced by TWEAK pathway deficiency or TWEAK-blocking monoclonal antibody. Neutrophil and macrophage infiltrates, chemokines, cytokines, and matrix metalloproteinase expression were reduced in the TWEAK-deficient colon after TNBS administration; however, systemic adaptive immune responses to trinitrophenyl were not altered. Fn14 is expressed on colon epithelial cells in TNBS colitis, and TWEAK induces epithelial production of pathogenic mediators. TWEAK also regulates intestinal epithelial turnover, as evidenced by reduced epithelial cell death after gamma-irradiation injury in TWEAK and Fn14 knockout mice.

CONCLUSIONS

Our studies elucidate a nonredundant TWEAK-intestinal epithelial cell axis and suggest that blocking TWEAK may dampen chronic intestinal inflammation and allow normal epithelial repair.

TNF-like weak inducer of apoptosis (TWEAK) induces inflammatory and proliferative effects in human kidney cells

Members of the TNF-ligand and receptor superfamilies are important in the pathogenesis of lupus nephritis, a major cause of mortality and morbidity in SLE. TWEAK, a member of the TNF-ligand superfamily, is markedly increased in urine from patients with active lupus nephritis, and urinary TWEAK levels significantly correlate with renal disease activity. To support a possible role of TWEAK in the pathogenesis of lupus nephritis and other inflammatory nephritides, we examined the effects of TWEAK in human kidney mesangial cells, podocytes and tubular cells, following our demonstration of the presence of the TWEAK receptor Fn14 on these cells. We found that TWEAK induces human kidney cells to express multiple inflammatory mediators, including RANTES, MCP-1, IP-10, MIP-1alpha, ICAM-1, and VCAM-1. Cytokine production is mediated through NF-kappaB activation, and is inhibited by anti-TWEAK monoclonal antibodies. TWEAK stimulated chemokines induced migration of human PBMC, particularly monocytes/macrophages. Furthermore, we found that TWEAK promotes kidney infiltration of inflammatory cells, and stimulates proliferation of kidney cells in vitro and in vivo. Thus, TWEAK may play an important pathogenic role in the development of glomerulonephritis by promoting a local inflammatory environment and inducing kidney cell proliferation. Blocking TWEAK/Fn14 interactions may be a promising therapeutic target in immune-mediated renal diseases.

The cytokine TWEAK modulates renal tubulointerstitial inflammation

TNF-like weak inducer of apoptosis (TWEAK) is a member of the TNF superfamily of cytokines. In addition to binding and activating the fibroblast growth factor-inducible 14 receptor, TWEAK may regulate apoptosis, proliferation, and inflammation; however, the role of this system in kidney injury is unknown. In vitro, it was found that TWEAK induced the sustained activation of NF-kappaB in a murine tubular epithelial cell line (MCT). NF-kappaB activation was associated with degradation of IkappaB-alpha; translocation of RelA to the nucleus; and increased mRNA and protein expression of monocyte chemoattractant protein-1, RANTES, and IL-6. Similarly, in vivo, the systemic administration of TWEAK induced renal NF-kappaB activation, chemokine and IL-6 expression, and interstitial inflammation in mice. Parthenolide, which prevents IkappaB-alpha degradation, inhibited TWEAK-induced NF-kappaB activation and prevented the aforementioned changes in vitro and in vivo. After folic acid-induced acute kidney injury, fibroblast growth factor-inducible 14 expression increased in mouse tubular epithelium. Neutralization of TWEAK decreased the expression of chemokines in tubular cells and reduced interstitial inflammation. In conclusion, TWEAK has NF-kappaB-dependent proinflammatory effects on tubular epithelial cells in vitro and in vivo. Moreover, blockade of TWEAK reduces tubular chemokine expression and macrophage infiltration, suggesting that TWEAK modulates acute kidney injury by regulating the inflammatory response.

Risk factors and attributable mortality of late aspergillosis after T-cell depleted hematopoietic stem cell transplantation

AIM

Invasive aspergillosis occurs in 5-15% of allogeneic hematopoietic stem cell transplant (HSCT) recipients. Through the 1990s there has been an increase in the incidence of late aspergillosis (LA). We report on the incidence, risk factors, and attributable mortality of LA in a cohort of 398 adult and pediatric patients at Memorial Sloan-Kettering Cancer Center from January 1999 through December 2003.

METHODS

LA was defined as occurring > 40 days post HSCT. LA cases were identified by prospective surveillance and examination of a computerized database. Probable or definite aspergillosis was defined by standard EORTC/MSG criteria. Mortality was attributed to LA if it caused or significantly contributed to death.

RESULTS

The overall incidence of LA in our cohort was 4.1%. Median time from stem cell infusion to diagnosis of LA was 164 days (range 68-677) after HSCT. The incidence of LA among unmodified, T-cell depleted, or reduced intensity HSCT was 2.2%, 4%, and 6.8%, respectively (P not significant). Risk factors for LA were grade II-IV acute graft-versus-host disease (GVHD) (P=0.002), chronic GVHD (P=0.01), secondary neutropenia (P=0.02), and reduced intensity conditioning containing alemtuzumab (P=0.01). LA was the immediate cause of death in 1 of 10 (10%) T-cell depleted, 2 of 2 (100%) unmodified, and 1 of 4 (25%) of reduced-intensity HSCT.

CONCLUSIONS

LA developed a median 164 days post HSCT. All-cause 30-day mortality of LA was 56.3%. The majority of LA cases died of concurrent infections and not from invasive aspergillosis.

Invasive adenoviral infections in T-cell-depleted allogeneic hematopoietic stem cell transplantation: high mortality in the era of cidofovir

BACKGROUND

Adenovirus (ADV) infection occurs in 5-21% of allogeneic hematopoietic stem cell transplants (HSCT). Symptomatic enteritis and hemorrhagic cystitis may be encountered but are seldom fatal. In contrast, mortality rates of up to 75% are reported for adenoviral pneumonia or hepatitis. Cidofovir is currently being increasingly used for treatment of adenoviral infections after HSCT. The efficacy of cidofovir in patients with invasive adenoviral infection is not established.

FINDINGS

We reviewed 687 adult and pediatric patients who received allogeneic HSCT at our institution from 1998 through June 2005. ADV was isolated from 64 (9.3%) patients. Eleven patients received cidofovir for invasive disease occurring at median 39 days (range 3-145) post HSCT. The median age was 40 (range 6-61) years. Seventy-three percent received a T-cell-depleted graft and 18% had grade 3-4 graft-versus-host disease (GVHD) of the gut. Three out of 3 (100%) patients with adenoviral pneumonia died. One patient with hepatitis, cholecysitis, and viremia cleared the infection after 3 months. Two out of 7 (28.6%) patients with hemorrhagic colitis or cystitis died of ADV (1 with extensive GVHD).

CONCLUSION

Mortality rates of ADV pneumonitis after allogeneic HSCT remain high in the era of cidofovir. Clinical trials are needed to evaluate management strategies for this life-threatening infection.

Predictors for persistent cytomegalovirus reactivation after T-cell-depleted allogeneic hematopoietic stem cell transplantation

Cytomegalovirus (CMV) reactivation occurs in up to 60% of CMV-seropositive recipients after allogeneic hematopoietic stem cell transplantation (HSCT). The incidence of CMV disease among T-cell-depleted HSCT patients has been reported from 5-15%. The incidence of reactivation refractory to antivirals in this population is not well studied.

METHODS

In this retrospective study we characterized the outcome of CMV reactivation in a cohort of 255 adult and pediatric patients who underwent T-cell-depleted HSCT at Memorial Sloan-Kettering Cancer Center from September 1999 through August 2004. CMV infection was monitored by the pp65 antigenemia assay (CMV Ag). Persistent reactivation was defined as antigenemia positivity >21 days on antiviral therapy.

RESULTS

Of 118 CMV-seropositive recipients, 69 (58.4%) had reactivated CMV. Twenty of 69 (29%) developed persistent reactivation at first episode of reactivation, and 7 (10%) in subsequent episode. All patients with persistent reactivation received >/=2 antivirals and CMV hyperimmune globulin; 45% received combination antiviral therapy. The median duration of persistent reactivation was 98 days, range 31-256 days. In multivariate analysis, maximum CMV Ag >25 cells/slide was associated with persistent reactivation (odds ratio 16.2%, 95% confidence interval 4-64, P<0.0001). CMV disease occurred in 6/27 (22%) patients with persistent reactivation. Patients with persistent reactivation had lower CD4(+) and CD8(+) lymphocyte counts compared with those with non-persistent reactivation at day +90 post HSCT (P=0.01 and 0.02, respectively).

CONCLUSIONS

Persistent reactivation occurred in 39% of T-cell-depleted HSCT despite treatment with currently available antivirals. Maximum CMV Ag >25 cells/slide was associated with persistent CMV reactivation. More effective treatment modalities are needed for this high-risk population to reduce CMV-associated morbidity and mortality.

Preemptive diagnosis and treatment of Epstein-Barr virus-associated post transplant lymphoproliferative disorder after hematopoietic stem cell transplant: an approach in development

Hematopoietic stem cell transplant (HSCT) recipients are at risk for Epstein-Barr virus (EBV)-associated, post transplant lymphoproliferative disorder (PTLD). Studies have suggested that early treatment may improve the outcome of patients with PTLD. Thus, significant attention has been focused on PCR-based approaches for preemptive (i.e., prior to clinical presentation) diagnosis. Reports from several transplant centers have demonstrated that HSCT recipients with PTLD generally have higher concentrations of EBV DNA in the peripheral blood than patients without PTLD. However, the PCR values of patients with PTLD typically span multiple orders of magnitude and overlap significantly with values from patients without PTLD. Thus, questions remain about the sensitivity and predictive value of these assays. Preemptive strategies using rituximab and/or EBV-specific cytotoxic T lymphocytes have been evaluated in patients with elevated EBV viral loads. We review the current literature, discuss our institutional experience and identify several areas of future research that could improve the diagnosis and treatment of this life-threatening disorder in HSCT recipients.

Inhibition of NOS-2 induction in LPS-stimulated J774.2 cells by 1, 5-isoquinolinediol, an inhibitor of PARP

Activation of both poly (ADP-ribose) polymerase (PARP) and inducible nitric oxide synthase (NOS-2) have been implicated in the pathogenesis of various forms of inflammation, therefore compounds which may simultaneously inhibit both pathways are of potential therapeutic interest. We tested the influence of potent inhibitor of PARP, 1, 5-isoquinolinediol (ISO), on NOS-2 induction in model of mouse macrophages (cell line J774.2) stimulated with lipopolysaccharide (1 microg/ml). Pretreatment with ISO (1-300 microM) resulted in dose-dependent inhibition of accumulation of NOS-2-derived nitrite in culture medium (IC(50) = 9,3 microM) as well as inhibition of NOS-2 protein induction in cultured J774.2 cells; ISO given 10 hours after LPS did not influence activity of NOS-2. Interestingly, another PARP inhibitor, 3-aminobenzamide (3-AB, 10-3000 microM), did not influence 24-hr nitrite accumulation in J774.2 cell culture, either administered 15 minutes prior to LPS or 10 hrs after LPS. Scavenging of reactive oxygen species by use of mixture of SOD and catalase (SOD/Cat, 100/300 - 1000/3000 U/ml) as well as cell permeable SOD-mimetic [Mn(III)TBAP, 1- 100 microM], did not influence NOS-2 induction in J774.2 cells. In summary, we identified 1, 5-isoquinoline as potent inhibitor of induction of NOS-2 in LPS-treated mouse macrophages. The exact mechanism of inhibitory action of this compound on NOS-2 induction requires further investigation.

Inhibition of nuclear factor-kappaB attenuates artherosclerosis in apoE/LDLR - double knockout mice

Nuclear factor - kappaB (NF-kappaB) is a good therapeutic target for cardiovascular disease and numerous efforts are being made to develop safe NF-kappaB inhibitors. Nowadays many authors address NF-kappaB as a major therapeutic target in atherosclerosis, especially for preventive measures, in the light of two main hypothesis of atherosclerosis: oxidation and inflammation. We hypothesized that ammonium pyrrolidinedithioocarbamate (PDTC) - a well-known inhibitor of NF-kappaB could inhibit the development of atherosclerosis in this experimental model. We used apoE/LDLR - DKO mouse model, which is considered as a one of the best models to study the anti-atherosclerotic effect of drugs. In this model PDTC inhibited atherogenesis, measured both by "en face" method (25,15+/-2,9% vs. 15,63+/-0,6%) and "cross-section" method (565867+/-39764 microm2 vs. 291695+/-30384 microm2). Moreover, PDTC did not change the profile of cholesterol and triglycerides in blood. To our knowledge, this is the first report that shows the effect of PDTC on atherogenesis in gene-targeted apoE/LDLR - double knockout mice.

TWEAK induces liver progenitor cell proliferation

Progenitor ("oval") cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particularly when hepatocyte replication is impaired. The regulation of oval cell proliferation is incompletely understood. Herein we present evidence that a TNF family member called TWEAK (TNF-like weak inducer of apoptosis) stimulates oval cell proliferation in mouse liver through its receptor Fn14. TWEAK has no effect on mature hepatocytes and thus appears to be selective for oval cells. Transgenic mice overexpressing TWEAK in hepatocytes exhibit periportal oval cell hyperplasia. A similar phenotype was obtained in adult wild-type mice, but not Fn14-null mice, by administering TWEAK-expressing adenovirus. Oval cell expansion induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) was significantly reduced in Fn14-null mice as well as in adult wild-type mice with a blocking anti-TWEAK mAb. Importantly, TWEAK stimulated the proliferation of an oval cell culture model. Finally, we show increased Fn14 expression in chronic hepatitis C and other human liver diseases relative to its expression in normal liver, which suggests a role for the TWEAK/Fn14 pathway in human liver injury. We conclude that TWEAK has a selective mitogenic effect for liver oval cells that distinguishes it from other previously described growth factors.

Pre- and post-engraftment bloodstream infection rates and associated mortality in allogeneic hematopoietic stem cell transplant recipients

We report on bloodstream infection (BSI) rates, risk factors, and outcome in a cohort of 298 adult and pediatric hematopoietic stem cell transplantation (HSCT) recipients at Memorial Sloan-Kettering Hospital from September 1999 through June 2003. Methods. Prospective surveillance study. BSI rates are reported per 10,000 HSCT days. Date of engraftment is defined as the first of at least 3 consecutive dates of absolute neutrophil count >500/mm(3) after stem cell infusion. BSI severity grades: severe (intravenous antibiotics), life threatening (sepsis), or fatal (caused or contributed to death). Results. The incidence of pre- and post-engraftment BSI was 22% and 19.5%, respectively. Pre-engraftment highest rates were observed for viridans streptococci (58), Enterobacteriaceae (39), and Enterococcus faecium (34). Post-engraftment rates ranged from 0.2 to 2.9 without any predominant pathogen. In multivariate analyses, pre-engraftment BSI was associated with diagnosis of chronic myelogenous leukemia, age >18 years and peripheral blood stem cell graft; post-engraftment BSI was associated with acute graft-versus-host disease, neutropenia, and liver or kidney dysfunction. Attributable mortality was 12.5% and 1.7% for pre- and post-engraftment BSI, respectively. BSI fatality rates were 24% for viridans streptococci, 8% for E. faecium, 11% for Staphylococcus aureus, and 67% for Candida. Conclusions. Pre-engraftment BSI, especially by viridans streptococci and E. faecium, was associated with substantial attributable mortality. Post-engraftment BSI was a marker of post-transplant complications and rarely the primary cause of death.

Endothelial action of thienopyridines and thienopyrimidinones in the isolated guinea pig heart

Antiplatelet thienopyridines (ticlopidine, clopidogrel) and their thienopyrimidinone congeners, induce prostacyclin-dependent thrombolysis in vivo. Here we tested whether thienopyridines (ticlopidine, clopidogrel, and its enantiomer without antiplatelet properties) and structurally related thienopyrimidinones release NO from coronary endothelium in the isolated guinea pig heart, perfused according to Langendorff technique. The involvement of endothelium-derived NO in coronary vasodilation induced by these agents was assessed by effect of L-N(G)-nitro-arginine methyl ester (L-NAME). In addition, effect of thienopyridines or thienopyrimidinones on nitrite accumulation in cultured endothelium was assayed. Tienopyridines (10-100 micromol L(-1)) and thienopyrimidinones (10-30 micromol L(-1)) produced concentration-dependent increase in coronary flow comparable to that induced by acetylcholine (0.1 micromol L(-1)) or bradykinin (3 nmol L(-1)) which was inhibited by L-NAME (by 50-70%) but not by indomethacin. Furthermore, thienopyridines and thienopyrimidinones caused NO release from cultured endothelial cells. In conclusion, both thienopyridines independently from their antiplatelet action and their thienopyrimidinone congeners that are devoid of antiplatelet action stimulate coronary endothelium to release NO. Endothelial action of these compounds merits further investigation.

Treatment of menorrhagia in women undergoing hematopoietic stem cell transplantation

The management of uterine bleeding in female transplant patients over a 3-year period at our institution was reviewed. A total of 33 females who had undergone allogeneic hematopoietic stem cell transplant were identified as having received gynecologic consultation for the diagnosis of menorrhagia. Hormone therapy achieved a resolution of symptoms in 32 (97%) of the patients, and 26 (79%) required only one hormone regimen. Following resolution of symptoms, transition to standard-dose oral contraceptive pills as maintenance therapy prevented recurrent menorrhagia due to high circulating estrogen levels. Alternatives for patients who are unable to tolerate oral administration and those with hepatotoxicity are also discussed.

Involvement of platelet activating factor in immediate heart response to lipopolysaccharide

Although lipopolysaccharide (LPS) is recognized to induce a biphasic cardiovascular response its mechanism is not fully elucidated. In this study we analysed the involvement of PAF, TXA(2) and cysteinyl leukotrienes (cysLTs) in the acute cardiovascular effects of LPS in the isolated rat heart as well as in delayed phase of LPS response using a surrogate cellular model of the induction of NOS-2 by LPS in mouse macrophages. Perfusion of rat hearts with LPS resulted, in an immediate fall in heart contractility and coronary flow by 2.5 +/- 0.59 ml x min(-1) and 560 +/- 81 mmHg x sec(-1), respectively. This response was fully blocked by platelet activating factor (PAF) antagonist - WEB 2170 and partially inhibited, by inhibitor of cyclooxygenase (indomethacin) or by inhibitor of thromboxane synthase (camonagrel). The inhibition of leukotriene synthesis (BAY x1005) or cysLTs receptors (BAY x7195) was without effect. Administration of stable PAF analog (methylcarbamyl-PAF - MC-PAF) alone, mimicked heart response to LPS. In cultured mouse macrophages, MC-PAF did not induce NOS-2 expression and when given with LPS it slightly potentiated NOS-2 induction by LPS. However, in presence of WEB 2170 NOS-2 induction by LPS was inhibited in a dose-dependent manner. Inhibition of cyclooxygenase and leukotriene pathways had no effect on NOS-2 induced by LPS. These results indicate that PAF and TXA(2) but not cysLTs mediate the instant heart response induced by LPS, while PAF alone mediates a delayed NOS-2 induction by LPS. Accordingly, PAF may constitute the mediator that links acute and delayed phases of LPS-induced cardiovascular response.

High rates of infection and colonization by nontuberculous mycobacteria after allogeneic hematopoietic stem cell transplantation

Nontuberculous mycobacteria (NTM) are essentially ubiquitous and can infect both immunocompetent and immunocompromised hosts. However, NTM infection is surprisingly uncommon in reports from allogeneic hematopoietic stem cell transplant (alloSCT) centers that do not routinely perform allograft T-cell depletion. We reviewed medical records for all adult patients who underwent alloSCT at our center between January 1993 and December 2001. American Thoracic Society and Centers for Disease Control and Prevention guidelines Were used to define definite, probable, and possible NTM infection. Of 571 patients, 36 of 372 (9.7%) T-cell depleted and 14 of 199 (7.0%) conventional alloSCT recipients (P=0.26) had a positive culture for NTM after alloSCT. Of the 50 patients with NTM infection, 16 had definite infection and 34 had probable or possible infection. Rates of NTM infection were 5 to 20-fold higher than rates reported by other centers. Of the 16 definite infections, nine were caused by Mycobacterium haemophilum. Two patients had disseminated M. avium complex (MAC) infection and one had a vascular catheter infected by MAC. Three patients died from complications of NTM infection. Patients with probable or possible NTM infection had markedly different epidemiology, risk factors, site and species of NTM infection, and prognosis than patients with definite NTM infection.

Dual role for TWEAK in angiogenic regulation

Angiogenic regulators modulate endothelial cell functions, including proliferation, migration, secretion, and adhesion, through their action on endothelial cells or other cell types. TWEAK, a novel member of the tumor necrosis factor family, appears to be a pro-angiogenic agent on the basis of previous studies demonstrating its ability to induce interleukin-8 production by epithelial tumor lines, stimulate proliferation of human vascular cell types and neovascularization in rat corneas. Here, we further characterized the angiogenic potential of TWEAK, revealing a dual role for TWEAK as an angiogenic regulator. We demonstrate that TWEAK is a potent inducer of endothelial cell survival and cooperates with basic fibroblast growth factor to induce the proliferation and migration of human endothelial cells and morphogenesis of capillary lumens. In contrast, TWEAK antagonizes the morphogenic response of endothelial cells to vascular endothelial growth factor (VEGF) without inhibiting VEGF-induced survival or proliferation. Thus, our observations suggest that TWEAK may differentially regulate microvascular growth, remodeling and/or maintenance in vivo, depending upon the angiogenic context.

Fiberoptic bronchoscopy in allogeneic bone marrow transplantation: findings in the era of serum cytomegalovirus antigen surveillance

STUDY OBJECTIVES

Pulmonary complications occur in half of allogeneic bone marrow transplantation (BMT) patients. The incidence of these complications has been reduced by prophylaxis against Pneumocystis carinii pneumonia, preemptive therapy in patients at high risk for cytomegalovirus (CMV) reactivation, and, more recently, screening for serum CMV antigen. Since fiberoptic bronchoscopy (FOB) has historically been the primary diagnostic test to evaluate BMT patients with pulmonary disease, a review was performed to determine the impact, if any, that current prophylaxis and screening policies may have had on FOB utility.

DESIGN

The records of 174 adult patients undergoing BMT between January 1997 and December 1999 were reviewed to determine the diagnostic yield of FOB and the frequency by which FOB altered management.

RESULTS

Sixty-one patients underwent 76 bronchoscopies. FOB was diagnostic in 32 patients (42.1% of cases) and directly changed management in 24 patients (31.6% of cases). Half of these changes included the withdrawal of an antimicrobial agent. The most common findings were infection (32 cases) and diffuse alveolar hemorrhage (6 cases). CMV was the most prevalent infection identified, but FOB resulted in the addition of antiviral therapy to only two patients. P carinii pneumonia was not diagnosed in any patient studied.

CONCLUSIONS

These data suggest a changing spectrum of pulmonary disease in BMT patients. FOB has limited impact on the diagnoses of CMV disease or P carinii pneumonia with current prophylaxis and screening strategies. It may be useful in identifying other infectious etiologies and in eliminating unnecessary antimicrobials.