Antibody mediated rejection associated with complement factor h-related protein 3/1 deficiency successfully treated with eculizumab.

Antibody mediated rejection (AMR) activates the classical complement pathway and can be detrimental to graft survival. AMR can be accompanied by thrombotic microangiopathy (TMA). Eculizumab, a monoclonal C5 antibody prevents induction of the terminal complement cascade (TCC) and has recently emerged as a therapeutic option for AMR. We present a highly sensitized 13-year-old female with end-stage kidney disease secondary to spina bifida-associated reflux nephropathy, who developed severe steroid-, ATG- and plasmapheresis-resistant AMR with TMA 1 week post second kidney transplant despite previous desensitization therapy with immunoglobulin infusions. Eculizumab rescue therapy resulted in a dramatic improvement in biochemical (C3; creatinine) and hematological (platelets) parameters within 6 days. The patient was proven to be deficient in complement Factor H-related protein 3/1 (CFHR3/1), a plasma protein that regulates the complement cascade at the level of C5 conversion and has been involved in the pathogenesis of atypical hemolytic uremic syndrome caused by CFH autoantibodies (DEAP-HUS). CFHR1 deficiency may have worsened the severe clinical progression of AMR and possibly contributed to the development of donor-specific antibodies. Thus, screening for CFHR3/1 deficiency should be considered in patients with severe AMR associated with TMA.

Genetic susceptibility to invasive meningococcal disease: MBL2 structural polymorphisms revisited in a large case-control study and a systematic review.

Invasive infection caused by Neisseria meningitidis is a worldwide public health problem. Previous reports have indicated that carriage of common 'defective' structural polymorphisms of the host mannose-binding lectin gene (MBL2) greatly increases an individual's risk of developing the disease. We report the largest case-control study so far to investigate the effect of these polymorphisms in meningococcal disease (296 PCR-positive cases and 5196 population controls, all of European ancestry) and demonstrate that no change in risk is associated with the polymorphisms overall or in any age-defined subgroup. This finding contrasts with two smaller studies that reported an increase in risk. A systematic review of all studies of MBL2 polymorphisms in people of European ancestry published since 1999, including 24,693 individuals, revealed a population frequency of the combined 'defective'MBL2 allele of 0.230 (95% confidence limits: 0.226-0.234). The past reported associations of increased risk of meningococcal disease were because of low 'defective' allele frequencies in their study control populations (0.13 and 0.04) that indicate systematic problems with the studies. The data from our study and all other available evidence indicate that MBL2 structural polymorphisms do not predispose children or adults to invasive meningococcal disease.

Complement factor H deficiency and endocapillary glomerulonephritis due to paternal isodisomy and a novel factor H mutation.

Complement factor H (CFH) is a regulator of the alternative complement activation pathway. Mutations in the CFH gene are associated with atypical hemolytic uremic syndrome, membranoproliferative glomerulonephritis type II and C3 glomerulonephritis. Here, we report a 6-month-old CFH-deficient child presenting with endocapillary glomerulonephritis rather than membranoproliferative glomerulonephritis (MPGN) or C3 glomerulonephritis. Sequence analyses showed homozygosity for a novel CFH missense mutation (Pro139Ser) associated with severely decreased CFH plasma concentration (<6%) but normal mRNA splicing and expression. The father was heterozygous carrier of the mutation, but the mother was a non-carrier. Thus, a large deletion in the maternal CFH locus or uniparental isodisomy was suspected. Polymorphic markers across chromosome 1 showed homozygosity for the paternal allele in all markers and a lack of the maternal allele in six informative markers. This combined with a comparative genomic hybridization assay demonstrated paternal isodisomy. Uniparental isodisomy increases the risk of homozygous variations in other genes on the affected chromosome. Therefore, we analyzed other susceptibility genes on chromosome 1 and found no sequence variation in membrane cofactor protein, but homozygosity for the common deletion of CFH-related proteins 1 and 3, which may contribute to the early onset of disease.

Trimer stability of YadA is critical for virulence of Yersinia enterocolitica.

Yersinia adhesin A (YadA) is a trimeric autotransporter adhesin with multiple functions in host-pathogen interactions. The aim of this study was to dissect the virulence functions promoted by YadA in vitro and in vivo. To accomplish this, we generated Yersinia enterocolitica O:8 mutants expressing point mutations in YadA G389, a highly conserved residue in the membrane anchor of YadA, and analyzed their impact on YadA expression and virulence functions. We found that point mutations of YadA G389 led to impaired transport, stability, and surface display of YadA. YadA G389A and G389S mutants showed comparable YadA surface expression, autoagglutination, and adhesion to those of wild-type YadA but displayed reduced trimer stability and complement resistance in vitro and were 10- to 1,000-fold attenuated in experimental Y. enterocolitica infection in mice. The G389T, G389N, and G389H mutants lost trimer stability, exhibited strongly reduced surface display, autoagglutination, adhesion properties, and complement resistance, and were avirulent (>10,000-fold attenuation) in mice. Our data demonstrate that G389 is a critical residue of YadA, required for optimal trimer stability, transport, surface display, and serum resistance. We also show that stable trimeric YadA protein is essential for virulence of Y. enterocolitica.

The transcription factor early growth response 1 (Egr-1) advances differentiation of pre-B and immature B cells.

In mature B lymphocytes, the zinc finger transcription factor early growth response 1 (Egr-1) is one of the many immediate-early genes induced upon B cell antigen receptor engagement. However, its role during earlier stages of lymphopoiesis has remained unclear. By examining bone marrow B cell subsets, we found Egr-1 transcripts in pro/pre-B and immature B lymphocytes, and Egr-1 protein in pro/pre-B-I cells cultivated on stroma cells in the presence of interleukin (IL)-7. In recombinase-activating gene (RAG)-2-deficient mice overexpressing an Egr-1 transgene in the B lymphocyte lineage, pro/pre-B-I cells could differentiate past a developmental block at the B220(low) BP-1(-) stage to the stage of B220(low) BP-1(+) pre-B-I cells, but not further to the B220(low) BP-1(+) CD25(+) stage of pre-B-II cells. Therefore, during early B lymphopoiesis progression from the B220(low) BP-1(-) IL-2R- pro/pre-B-I stage to the B220(low) BP-1(+) IL-2R+ pre-B-II stage seems to occur in at least two distinct steps, and the first step to the stage of B220(low) BP-1(+) pre-B-I cells can be promoted by the overexpression of Egr-1 alone. Wild-type mice expressing an Egr-1 transgene had increased proportions of mature immunoglobulin (Ig)M+ B220(high) and decreased proportions of immature IgM+ B220(low) bone marrow B cells. Since transgenic and control precursor B cells show comparable proliferation patterns, overexpression of Egr-1 seems also to promote entry into the mature B cell stage. Analysis of changes in the expression pattern of potential Egr-1 target genes revealed that Egr-1 enhances the expression of the aminopeptidase BP-1/6C3 in pre-B and immature B cells and upregulates expression of the orphan nuclear receptor nur77 in IgM+ B cells.

Optimizing melphalan pharmacokinetics in regional melanoma therapy: does correcting for ideal body weight alter regional response or toxicity?

BACKGROUND: This study aims to determine what effect correcting melphalan dosing for ideal body weight (IBW) has on toxicity and response in isolated limb infusion (ILI) in patients with advanced extremity melanoma. METHODS: This was an open observational study examining whether correcting the melphalan dose for IBW will influence response and toxicity in patients undergoing ILI for advanced extremity melanoma in 41 patients undergoing 42 procedures (13 without correction for IBW; and 29 with correction for IBW). Melphalan pharmacokinetics, limb toxicity, serologic toxicity, and response at 3 months were compared. RESULTS: The corrected group had a lower estimated limb volume (V (esti)) to melphalan volume at steady state (V (ss)) (P < .0001) ratio as well as lower incidence of grade > or =3 regional toxicity, serologic toxicity, and compartment syndrome (P = .0249, P = .027, P = .02). There was a positive correlation of V (esti)/V (ss) to toxicity (P = .0127, r = .382). No significant difference in response (P = .3609) between the groups was found, although there was a trend of association between V (esti)/V (ss) and response (P = .051, r = .3383). CONCLUSIONS: Correcting for IBW in ILI lowers toxicity without significantly altering response rates.

Immune evasion by acquisition of complement inhibitors: the mould Aspergillus binds both factor H and C4b binding protein.

Pathogenic fungi represent a major threat particularly to immunocompromised hosts, leading to severe, and often lethal, systemic opportunistic infections. Although the impaired immune status of the host is clearly the most important factor leading to disease, virulence factors of the fungus also play a role. Factor H (FH) and its splice product FHL-1 represent the major fluid phase inhibitors of the alternative pathway of complement, whereas C4b-binding protein (C4bp) is the main fluid phase inhibitor of the classical and lectin pathways. Both proteins can bind to the surface of various human pathogens conveying resistance to complement destruction and thus contribute to their pathogenic potential. We have recently shown that Candida albicans evades complement by binding both Factor H and C4bp. Here we show that moulds such as Aspergillus spp. bind Factor H, the splicing variant FHL-1 and also C4bp. Immunofluorescence and flow cytometry studies show that the binding of Factor H and C4bp to Aspergillus spp. appears to be even stronger than to Candida spp. and that different, albeit possibly nearby, binding moieties mediate this surface attachment.

Complexity of the primary genetic response to mitogenic activation of human T cells.

We describe the isolation and characterization of more than 60 novel cDNA clones that constitute part of the immediate genetic response to resting human peripheral blood T cells after mitogen activation. This primary response was highly complex, both in the absolute number of inducible genes and in the diversity of regulation. Although most of the genes expressed in activated T cells were shared with the activation response of normal human fibroblasts, a significant number were more restricted in tissue specificity and thus likely encode or effect the differentiated functions of activated T cells. The activatable genes could be further differentiated on the basis of kinetics of induction, response to cycloheximide, and sensitivity to the immunosuppressive drug cyclosporin A. It is of note that cyclosporin A inhibited the expression of more than 10 inducible genes, which suggests that this drug has a broad genetic mechanism of action.

Mitogen-induced genes are subject to multiple pathways of regulation in the initial stages of T-cell activation.

The delivery of a mitogenic signal to T cells via any one of several cell surface molecules elicits a variety of intracellular responses, some or all of which regulate subsequent gene expression events. The expression of nine novel mitogen-induced genes in response to various T-cell-activating agents was examined to evaluate the diversity of pathways which regulate such genes. The relative contribution of distinct secondary signals, individually or together, to mitogen-stimulated gene induction and the capability of individual genes to respond to the sometimes divergent signals generated from different cell surface structures is addressed. The activation of T cells with mitogenic monoclonal antibodies directed against the CD2 or CD3 cell surface molecules, or with phytohemagglutinin, induced all nine genes. Thus, stimulation by fully mitogenic agents regardless of cell surface-binding specificity correlated with the expression of all of the genes studied. However, heterogeneous patterns of gene expression, encompassing five regulatory classes, were revealed by the use of phorbol 12-myristate 13-acetate, calcium ionophore, and anti-CD28 monoclonal antibody, agents which mediated only a subset of intracellular events and thus an incomplete mitogenic signal. Interleukin-2 and two novel lymphokines represented one regulatory class that appeared to require unique transcriptional activation signals relative to the other mitogen-induced genes. As demonstrated in the accompanying paper (P. F. Zipfel, S. G. Irving, K. Kelly, and U. Siebenlist, Mol. Cell. Biol. 9:1041-1048, 1989), the immediate transcriptional response of T cells to mitogenic stimulation is quite complex, involving numerous genes beyond those which have been previously described. Furthermore, the discrimination of several regulatory phenotypes among these nine genes suggests that a multiplicity of signaling pathways extends from the cell surface to the level of transcription.

Variations in the complement regulatory genes factor H (CFH) and factor H related 5 (CFHR5) are associated with membranoproliferative glomerulonephritis type II (dense deposit disease).

INTRODUCTION: Membranoproliferative glomerulonephritis type II or dense deposit disease (MPGN II/DDD) causes chronic renal dysfunction that progresses to end stage renal disease in about half of patients within 10 years of diagnosis. Deficiency of and mutations in the complement factor H (CFH) gene are associated with the development of MPGN II/DDD, suggesting that dysregulation of the alternative pathway of the complement cascade is important in disease pathophysiology. SUBJECTS: Patients with MPGN II/DDD were studied to determine whether specific allele variants of CFH and CFHR5 segregate preferentially with the MPGN II/DDD disease phenotype. The control group was compromised of 131 people in whom age related macular degeneration had been excluded. RESULTS: Allele frequencies of four single nucleotide polymorphisms in CFH and three in CFHR5 were significantly different between MPGN II/DDD patients and controls. CONCLUSION: We have identified specific allele variants of CFH and CFHR5 associated with the MPGN II/DDD disease phenotype. While our data can be interpreted to further implicate complement in the pathogenesis of MPGN II/DDD, these associations could also be unrelated to disease pathophysiology. Functional studies are required to resolve this question.

Two regulatory domains are required for downregulation of c-myc transcription in differentiating U937 cells.

In many differentiating cells, a reduction of c-myc proto-oncogene expression is a prerequisite for terminal differentiation. The downmodulation of c-myc in differentiating cells is due to at least two different mechanisms: (i) an elongation block to c-myc transcription activated during an early phase of differentiation and (ii) an inhibition of transcription initiation activated during a later phase. In order to determine cis-acting target structures of the c-myc gene required for the late-phase downregulation of transcriptional initiation, we permanently transfected U937 cells with constructs containing the bacterial chloramphenicol acetyl transferase (CAT) gene driven by a 2.8 kb c-myc promoter region or deletions thereof. We determined two distinct domains in the c-myc promoter region both of which are essential for efficient terminal downregulation: a proximal domain and a distal domain which are located between base pairs -606 to -101, and between -2392 to -1396, respectively, relative to P1. The identification of two distinct regulatory elements suggests the requirement and cooperation of two regulatory factors as an essential event for mediating differentiation-induced downregulation of c-myc in monocytic cells. The implications of these results for deregulation of the translocated c-myc allele in Burkitt's lymphoma are discussed.

The human zinc finger protein EGR-4 acts as autoregulatory transcriptional repressor.

The human EGR-4 (AT133) gene represents one member of a family of four related zinc finger proteins, that are simultaneously and coordinately induced in resting cells upon growth stimulation. In order to characterise the function of the EGR-4 zinc finger protein, we have expressed the protein in the eukaryotic baculovirus system. The recombinant EGR-4 protein has a molecular mass of 78 kDa, as demonstrated by SDS-PAGE and Western blotting. DNA binding studies revealed that the EGR-4 protein binds to the EGR consensus motif GCGTGGGCG, but not to the G-rich regulatory ZIP-element of the human IL-2 gene, that is a binding site for EGR-1. EGR-4 functions as transcriptional repressor. Overexpression of EGR-4 mediates repression of a minimal c-fos promoter through a threefold EGR consensus site. Furthermore the EGR-4 protein displays autoregulatory activities. This protein downregulates expression of its own gene promoter in a dose dependent manner. A G-rich region in the EGR-4 promoter, located at position -106 to -82, could be identified as binding site for the recombinant EGR-4 protein. A comparison of the two related zinc finger proteins EGR-4 and EGR-1 revealed for each protein distinct and specific DNA binding- and transcriptional regulatory activities.

Factor H binds to washed human platelets.

BACKGROUND: Factor H regulates the alternative pathway of complement. The protein has three heparin-binding sites, is synthesized primarily in the liver and copurifies from platelets with thrombospondin-1. Factor H mutations at the C-terminus are associated with atypical hemolytic uremic syndrome, a condition in which platelets are consumed. Objectives The aim of this study was to investigate if factor H interacts with platelets. METHODS: Binding of factor H, recombinant C- or N-terminus constructs and a C-terminus mutant to washed (plasma and complement-free) platelets was analyzed by flow cytometry. Binding of factor H and constructs to thrombospondin-1 was measured by surface plasmon resonance. RESULTS: Factor H bound to platelets in a dose-dependent manner. The major binding site was localized to the C-terminus. The interaction was partially blocked by heparin. Inhibition with anti-GPIIb/IIIa, or with fibrinogen, suggested that the platelet GPIIb/IIIa receptor is involved in factor H binding. Factor H binds to thrombospondin-1. Addition of thrombospondin-1 increased factor H binding to platelets. Factor H mutated at the C-terminus also bound to platelets, albeit to a significantly lesser degree. CONCLUSIONS: This study reports a novel property of factor H, i.e. binding to platelets, either directly via the GPIIb/IIIa receptor or indirectly via thrombospondin-1, in the absence of complement. Binding to platelets was mostly mediated by the C-terminal region of factor H and factor H mutated at the C-terminus exhibited reduced binding.

Haemolytic uraemic syndrome and mutations of the factor H gene: a registry-based study of German speaking countries.

BACKGROUND: The aetiology of atypical haemolytic uraemic syndrome (aHUS) is, in contrast to classical, Shiga-like toxin induced HUS in children, largely unknown. Deficiency of human complement factor H and familial occurrence led to identification of the factor H gene (FH1) as the susceptibility gene, but the frequency and relevance of FH1 mutations are unknown. METHODS: We established a German registry for aHUS and analysed in all patients and 100 controls the complete FH1 gene by single strand confirmational polymorphism and DNA sequencing. In addition, complement C3 and factor H serum levels were assayed. Demographic data at onset of aHUS and follow up were compared for the mutation positive and negative groups. RESULTS: Of 111 patients with aHUS (68 female, 43 male, mean age 33 years) 14% had FH1 germline mutations, including two of eight patients with familial aHUS. For each of these eight patients, both parents were tested, and we were able to trace the mutation for five cases. In the other three cases (one with the mutation 3749 C/T, one with 3200 T/C, and one with 3566+1 G/A), we could not detect the mutation in either parent, although paternity was proven by genetic fingerprinting, suggesting that these subjects have new mutations. C3 was decreased in five mutation carriers but also in two non-carriers, and factor H was decreased in none of the carriers, but elevated in six carriers and 15 non-carriers. Clinical parameters including associated medications and diseases, and outcome of aHUS and of post-aHUS kidney transplantation were similar in the mutation positive and negative groups. CONCLUSION: FH1 germline mutations occur with considerable frequency in patients with aHUS. Hypocomplementaemia is not regularly associated with a germline mutation, and factor H serum levels can even be elevated. Screening for FH1 mutations contributes to the classification of aHUS.

Factor H and disease: a complement regulator affects vital body functions.

Factor H is a multidomain and multifunctional protein. As a complement regulator factor H determines the fate of newly formed C3b and controls formation and stability of C3 convertases both in the fluid phase and on cell surfaces. In addition, this plasma protein displays functions outside complement control as it has been suggested to act as an adhesion protein, to be a ligand for the cellular integrin receptor CR3 (CD11b/CD18) and to display chemotactic activity. Genetic and pathophysiological analyses describe a role for factor H in vital body functions. Depletion or the absence of factor H due to genetic reasons leads to unrestricted C3 consumption. A reduced amount of factor H in plasma or mutations within the factor H gene may lead to glomerulonephritis (type II MPGN) or hemolytic uremic syndrome (HUS). Certain pathogenic organisms have been shown to evade complement attack by binding factor H from the host. Such specific factor H binding components have been demonstrated on the surface of microbes, e.g., Streptococcus pyogenes and Neisseria gonorrhoeae. Here, we summarize the current knowledge how abnormalities in function of the central complement regulator factor H are associated with human diseases.

FHL-1/reconectin and factor H: two human complement regulators which are encoded by the same gene are differently expressed and regulated.

FHL-1/reconectin and factor H are two human complement regulators which are encoded by a single gene. FHL-1/reconectin contains the first 7 of 20 SCR protein domains of factor H and has four unique residues attached to its C-terminal end. The overlapping region of 445 amino acids explains the related complement regulatory functions of the two proteins. However, unique biological functions have also been reported for FHL-1/reconectin, such as cell adhesion and binding to microbial surfaces. Both proteins are synthesised and secreted by the liver. Extrahepatic synthesis occurs in a wide variety of cells, e.g. in monocytes, fibroblasts or neuronal cells. Unexpectedly, FHL-1/reconectin and factor H exhibit distinct expression patterns. This is also observed in disease situations such as in rheumatoid arthritis or malignancies. In rheumatoid arthritis a potentially protective role is suggested by the local synthesis of both FHL-1/reconectin and factor H in synovial fibroblasts and their induction by the anti-inflammatory agent dexamethasone and the cytokine IFN-gamma, but not by TNF-alpha. FHL-1/reconectin is overexpressed in certain tumor cells such as glioblastoma, conferring an exceptional resistance to such cells against complement mediated lysis. Although FHL-1/reconectin and factor H are encoded by a single gene, regulated by the same gene promoter and initiate transcription at the same start site, their transcripts are differently regulated. The putative control levels, which are responsible for this complex regulation, include transcript elongation, RNA processing, alternative splicing and differential poly(A) site selection.

The baculovirus expression vector pBSV-8His directs secretion of histidine-tagged proteins.

A novel baculovirus expression vector (pBSV-8His) directs secretion of recombinant proteins into the culture medium of infected insect cells. By providing a vector-encoded signal peptide upstream from a multiple cloning site, the product of the inserted cDNA is directed to the secretory pathway. In addition, a C-terminal His-tag allows convenient purification of the native protein directly from the culture medium in less than 5 h. The His-tag can be cleaved off the purified protein by utilizing an enterokinase cleavage site located directly N-terminal to the His sequence. By insertion of a coding sequence representing the human complement regulatory factor H-like (FHL-1) plasma protein into pBSV-8His, a high level of protein synthesis was demonstrated (9 micrograms/ml). The high level of production and the ease with which native protein can be purified almost to homogeneity, makes pBSV-8His particularly suitable for protein synthesis and purification. The combination of a vector-encoded signal peptide and a C-terminal His-tag allows production and direct purification of individual domains of secretory proteins in eukaryotic cells. This feature makes this novel vector extremely useful for structure function analyses of secretory proteins.

Functional properties of complement factor H-related proteins FHR-3 and FHR-4: binding to the C3d region of C3b and differential regulation by heparin.

The human factor H-related proteins FHR-3 and FHR4 are members of a family of proteins related to the complement factor H. Here, we report that the two proteins bind to the C3d region of complement C3b. The apparent K(A) values for the interactions of FHR-3 and FHR-4 with C3b are 7.5 x 10(6) M(-1) and 2.9 x 10(6) M(-1), respectively. Binding studies performed with C3b-coated pneumococci confirmed the results obtained with the biosensor system. A C-terminal construct of factor H showed similar binding characteristics. The interaction of FHR-3, but not of FHR4, with opsonised pneumococci was inhibited by heparin.

Analysis of the recognition mechanism of the alternative pathway of complement by monoclonal anti-factor H antibodies: evidence for multiple interactions between H and surface bound C3b.

The ability of the alternative pathway of complement to discriminate targets as either activators or non-activators is mediated by different binding properties of factor H to surface-associated C3b molecules. In the present study we have probed the interaction between H and C3b using five anti-H mAb. The binding sites of the mAb were mapped by Western blotting using both recombinant and trypsin-generated H fragments. Two mAb bound to CCP1 (90X, 196X), two to CCP5 (MRC OX24, 86X) and one to CCP8-15a (131X). At a molar ratio 2:1 of 125I-H:mAb all tested mAb enhanced binding of H to both activator- and non-activator-bound C3b. At higher concentrations two mAb had an inhibitory effect on H binding to surface-associated C3b (OX24, 131X). Thus the mAb 131X inhibits H binding to surface-bound C3b but unlike OX24 it does not bind to the previously described C3b binding site within or near CCP4-5. These results indicate that there is an additional interaction site on factor H for surface-bound C3b.

Localization and functional analysis of the cytosolic and extracellular CuZn superoxide dismutases in the human parasitic nematode Onchocerca volvulus.

This study describes the histological localization of two CuZn superoxide dismutases (SOD1 and SOD2) in the parasitic nematode Onchocerca volvulus, and a functional characterization of the 'extracellular' form of this enzyme (SOD2) which provides evidence that it is involved in the defense against environmental superoxide anion radicals. These essential enzymes are detected in larval and adult stages of the parasite, determined at the mRNA and protein levels by in situ hybridization and immunolocalization studies. These proteins are distributed throughout the worm, at various concentrations with particularly high levels produced in the hypodermis. In vitro maintenance of parasites indicated that SOD2 was secreted outside the parasite into the medium. Baculovirus constructs designed to test the ability of the SOD2 hydrophobic N-terminal region to function in processing and secretion confirmed the ability of this polypeptide sequence to direct the secretion of a marker protein, as well as of the mature SOD2 enzyme. Analyses of the native, mature SOD2 enzyme molecular mass, and the primary and quaternary structure, indicate that unlike other extracellular SODs, the SOD2 is active as a non-glycosylated dimer, rather than as a tetrameric glycoprotein. The detection of SOD2 outside of the parasite maintained in vitro, and the confirmation that the SOD2 is a secreted enzyme, indicate that this enzyme plays a role in the interactive biology of parasitic nematodes with their hosts.