Anti-MMP-9 Antibody: A promising therapeutic strategy for treatment of inflammatory bowel disease complications with fibrosis

BACKGROUND Despite medical treatments or surgical options, more than one-third of patients with Crohn's disease suffer from recurring fistulae. Matrix metalloprotease 9 (MMP-9), a type IV collagenase that cleaves components of the extracellular matrix leading to tissue remodeling, is upregulated in crypt abscesses and around fistulae suggesting an important role for this enzyme in fistula formation. Our aims were (1) to correlate serum levels of MMP-9 degradation products in patients with CD with the presence of fistulae and (2) to investigate the impact of selective MMP-9 inhibition in a mouse model of intestinal fibrosis. METHODS Serum MMP-9 degradation products were quantified in subjects affected with nonstricturing and nonpenetrating CD (n = 50), stricturing CD (n = 41), penetrating CD (n = 22), CD with perianal fistula (n = 29), and healthy controls (n = 10). Therapeutic efficacy of anti-MMP-9 monoclonal antibodies was assessed in a heterotopic xenograft model of intestinal fibrosis. RESULTS C3M, an MMP-9 degradation product of collagen III, demonstrated the highest serum levels in patients with penetrating CD and differentiated penetrating CD from other CD subgroups and healthy controls, P = 0.0005. Anti-MMP-9 treatments reduced collagen deposition and hydroxyproline content in day-14 intestinal grafts indicating reduced fibrosis. CONCLUSIONS The serologic biomarker C3M can discriminate penetrating CD from other CD subgroups and could serve as marker for the development of penetrating CD. Anti-MMP-9 antibody has therapeutic potential to prevent intestinal fibrosis in CD complications

Lethal Mycobacterium bovis Bacillus Calmette Guerin infection in nitric oxide synthase 2-deficient mice: cell-mediated immunity requires nitric oxide synthase 2

The role of nitric oxide (NO) in Mycobacterium bovis Bacillus Calmette Guerin (BCG) infection was investigated using nitric oxide synthase 2 (nos2)-deficient mice, because NO plays a pivotal protective role in M. tuberculosis infection. We demonstrate that nos2-deficient mice were unable to eliminate BCG and succumbed within 8 to 12 weeks to BCG infection (10(6) CFU) with cachexia and pneumonia, whereas all infected wild-type mice survived. The greatest mycobacterial loads were observed in lung and spleen. Nos2-deficient mice developed large granulomas consisting of macrophages and activated T cells and caseous necrotic lesions in spleen. The macrophages in granulomas from nos2-deficient mice had reduced acid phosphatase activities, suggesting that NO is required for macrophage activation. The absence of NOS2 affected the cytokine production of the Th1 type of immune response, except IL-18. Serum amounts of IL-12p40 were increased and IFN-gamma was decreased compared with wild-type mice. The lack of NOS2 resulted in an overproduction of TNF, observed throughout the infection period. Additionally, TNFR1 and TNFR2 shedding was altered compared with wild-type mice. Up-regulation of TNF may be compensatory for the lack of NOS2. The late neutralization of TNF by soluble TNF receptors resulted in heightened disease severity and accelerated death in nos2-deficient mice but had no effect in wild-type mice. In conclusion, the inability of nos2-deficient mice to kill M. bovis BCG resulted in an accumulation of mycobacteria with a dramatic activation of the immune system and overproduction of pro-inflammatory cytokines, which resulted in death

Circulating concentrations of interleukin-18, interleukin-18 binding protein, and gamma interferon in patients with alcoholic hepatitis

BACKGROUND: Alcoholic hepatitis (AH) is associated with dysregulated inflammatory and immune responses. interleukin-18 (IL-18), described as gamma interferon (gammaIFN)-inducible factor, and its natural antagonist, IL-18 binding protein (IL-18 BP), has not been fully studied in patients with AH. Thus, our aim was: (i) to determine plasma values of IL-18, IL-18 BP, gammaIFN, and tumor necrosis factor alpha (TNF)-alpha in patients hospitalized for biopsy-proven AH; (ii) to correlate these cytokines with the severity of AH, as assessed by Maddrey's discriminant function (DF), the degree of liver failure using the Child-Pugh score and blood neutrophils; (iii) to compare cytokines values in survivors and non-survivors. METHODS: Cytokines were measured using specific immunoassays within 7 days of admission. The diagnosis of AH was based on histology in all cases. We studied 43 cirrhotic patients with a Maddrey's DF>/=32 (severe AH), 29 patients with a score <32 (non-severe AH), 12 patients with abstinent alcoholic cirrhosis, and 10 healthy subjects. RESULTS: IL-18 and TNFalpha were increased in severe AH as compared with healthy subjects. Plasma IL-18 BP was elevated in patients with severe and non-severe AH as compared with healthy subjects. gammaIFN did not differ between groups. In patients with severe and non-severe AH, IL-18, IL-18 BP, TNFalpha, but not gammaIFN, were positively correlated to DF and Child-Pugh score. Neither IL-18 nor IL-18 BP correlated to TNFalpha. Patients who died (n=10) during the hospitalization had higher IL-18 BP and TNFalpha at admission as compared with survivors (322 [172-504] vs 222 [109-441] ng/ml; 7.5 [2.2-17.3] vs 3 [0.6-20] pg/ml, P<0.01, respectively). CONCLUSION: In cirrhotic patients with AH, IL-18, IL-18 BP, and TNFalpha correlate to the hepatitis severity and to the degree of liver failure. High IL-18 BP and TNFalpha at hospital admission in non-survivors suggest it may be of prognostic value

IL‐18‐independent cytotoxic T lymphocyte activation and IFN‐γ production during experimental acute graft‐versus‐host disease

Acute graft‐versus‐host disease (GvHD) is a serious complication after allogeneic bone marrow transplantation. Donor‐derived T cells infiltrate recipient target organs and cause severe tissue damage, often leading to death of the affected patient. Tissue destruction is a direct result of donor CD8+ T cell activation and cell‐mediated cytotoxicity. IL‐18 is a novel pro‐inflammatory cytokine with potent Th1 immune response‐promoting and cytotoxic T lymphocyte (CTL)‐inducing activity. IL‐18 is strongly induced in experimental mouse models and human patients with acute GvHD. However, the precise role of IL‐18 in the development of acute GvHD is still unknown. In this study, we have used IL‐18‐binding protein, a soluble IL‐18 decoy receptor, to specifically neutralize IL‐18 in vivo and in vitro. Our results demonstrate that IL‐18 is induced during GvHD. However, its effect in the induction of GvHD appears to be redundant, since neutralization of IL‐18 does not alter any disease parameter analyzed. Our study further shows that IFN‐γ production and CTL induction upon activation by T cell mitogens or by alloantigen does not involve IL‐18‐mediated amplification, in contrast to lipopolysaccharide‐induced IFN‐γ production. We conclude that IL‐18 expression correlates with the course of GvHD; however, its effect is dispensable for IFN‐γ and CTL induction for the initiation phase of this disease, most likely due to direct, IL‐18‐independent, CTL activation