Psoriasis is a chronic inflammatory disease of the skin characterized by epidermal hyperplasia, dermal angiogenesis, infiltration of activated T cells, and increased cytokine levels. One of these cytokines, IL-15, triggers inflammatory cell recruitment, angiogenesis, and production of other inflammatory cytokines, including IFN-gamma, TNF-alpha, and IL-17, which are all upregulated in psoriatic lesions. To investigate the role of IL-15 in psoriasis, we generated mAb's using human immunoglobulin-transgenic mice. One of the IL-15-specific antibodies we generated, 146B7, did not compete with IL-15 for binding to its receptor but potently interfered with the assembly of the IL-15 receptor alpha, beta, gamma complex. This antibody effectively blocked IL-15-induced T cell proliferation and monocyte TNF-alpha release in vitro. In a human psoriasis xenograft model, antibody 146B7 reduced the severity of psoriasis, as measured by epidermal thickness, grade of parakeratosis, and numbers of inflammatory cells and cycling keratinocytes. These results obtained with this IL-15-specific mAb support an important role for IL-15 in the pathogenesis of psoriasis.

In chronic heart failure (CHF), activation of the immune system occurs, which results in the production and release of proinflammatory cytokines, activation of the complement system, and production of autoantibodies. Thus, it is important to consider CHF as a systemic illness, not just a disease of the "pump." Immune activation in CHF can be divided into 2 broad categories: (1) immune activation by direct antigenic stimulation, or (2) immune activation secondary to cardiac injury that exposes "new antigens" capable of triggering an immune response against the heart. Cytokines are essential for the propagation and magnification of the immune response. They are involved in recruiting cells to the area of inflammation, stimulating cell division, proliferation, and differentiation. Circulating levels of the cytokine tumor necrosis factor-alpha (TNF-alpha) are increased in patients with CHF. Thus, cytokines are key elements of immune activation. Studies to investigate the role of increased TNF-alpha levels have failed to show a correlation with worsening CHF, most likely because the immune system is redundant, and other proinflammatory cytokines (interleukin [IL]-1 and IL-6) are known to be elevated in CHF. Approaches showing promise are those that enhance the natural anti-inflammatory response (eg, intravenous immunoglobulin (IVIG), immunoadsorption, immune-modulation therapy [IMT]), rather than those that specifically target a single type of cytokine. The mechanism by which IVIG modulates the immune system is unknown. Immunoadsorption involves the removal of specific antibodies from circulation. IMT works by inducing apoptosis in a sample of blood, which is then administered back to the patient. The immune system reacts by removing the apoptotic cells, thus inducing a systemic anti-inflammatory response.

The existence of specific probes for human genes makes it feasible to study genetic abnormalities, both inherited and acquired, at the level of the genome. In this respect, the antibody genes of man are of particular interest as they represent a multigene family expressed in many leukaemias and immunodeficiency diseases. Furthermore, selective deficiency of immunoglobulins has been described in healthy individuals. Normally, human adults express five types of immunoglobulin--IgM, IgD, IgG, IgE and IgA (defined by the class of heavy chain constant region). Subclasses are also known in IgG (IgG1, IgG2, IgG3 and IgG4) and IgA (IgA1 and IgA2) in which the immunoglobulins contain gamma 1, gamma 2, gamma 3 or gamma 4 and alpha 1 or alpha 2 CH regions, respectively. Recently, a healthy Tunisian person was described who showed abnormal patterns of immunoglobulin expression. The serum immunoglobulin of this individual, designated TAK3, was confined to IgM, IgD, IgG3, IgE and IgA2. We have now used cloned CH-gene probes to study the DNA of TAK3 as well as two brothers, also Tunisian but apparently unrelated to the individual TAK3, and who show a similar immunoglobulin abnormality. We found that in these cases there seems to have been a large chromosomal deletion which includes three gamma genes, an alpha gene and a pseudo-epsilon gene. This deletion accounts for the simultaneous absence of certain H-chain subclasses. These results illustrate that the human immunoglobulin gene locus is capable of undergoing rapid change, which is particularly apparent within small populations in which consanguinity is common.

An outbreak of acute respiratory tract infection occurred in Shanxi Province, China, from March to April 2006. Of the 254 patients affected by this outbreak, 247 patients were students of a senior high school; 1 of these patients died during the outbreak. Serological tests and blood culture revealed no evidence of bacterial infection. The results of direct reverse transcription-PCR or PCR performed with clinical specimens collected from the patients, including the sole patient who died, were positive for human adenoviruses (HAdVs) but negative for influenza virus, measles virus, rubella virus, mumps virus, parainfluenza virus, respiratory syncytial virus, and human enteroviruses. These findings were confirmed by enzyme-linked immunosorbent assay for HAdV immunoglobulin A, the conventional neutralization test, and viral isolation and identification. Sequencing of the entire hexon gene revealed that HdAV type 11a (HAdV-11a) belonging to the B2 species of HAdV was the etiological agent responsible for the outbreak. However, both the analysis of the phylogenetic relationship and the similarity plot indicated that the sequence of the 3' end of the hexon gene outside the hypervariable regions the HAdV-11a strain isolated in this outbreak may be a recombinant with the sequence of the HAdV-14 strain of species B2. Although isolates of HAdV species B2 seldom cause respiratory infections, they may pose a new global challenge with regard to acute respiratory diseases; this possibility cannot be overlooked and should be carefully considered. Hence, the need to establish and improve both epidemiological and virological surveillance of HAdV infections in China should be emphasized.

Mucosal immunoglobulin A (IgA) secreted by local plasma cells (PCs) is a critical component of mucosal immunity. Although IgA class switching can occur at mucosal sites, high-affinity PCs are optimally generated in germinal centers (GCs) in a T cell-dependent fashion. However, how CD4(+) helper T cells induce mucosal-homing IgA-PCs remains unclear. Here, we show that transforming growth factor beta1 (TGFbeta1) and interleukin 21 (IL-21), produced by follicular helper T cells (Tfh), synergized to generate abundant IgA-plasmablasts (PBs). In the presence of IL-21, TGFbeta1 promoted naive B cell proliferation and differentiation and overrode IL-21-induced IgG class switching in favor of IgA. Furthermore, TGFbeta1 and IL-21 downregulated CXCR5 while upregulating CCR10 on plasmablasts, enabling their exit from GCs and migration toward local mucosa. This was supported by the presence of CCR10(+)IgA(+)PBs in tonsil GCs. These findings show that Tfh contribute to mucosal IgA. Thus, mucosal vaccines should aim to induce robust Tfh responses.

The rat brain voltage-gated Na+ channel is composed of three glycoprotein subunits: the pore-forming alpha subunit and two auxiliary subunits, beta1 and beta2, which contain immunoglobulin (Ig)-like folds in their extracellular domains. When expressed in Xenopus oocytes, beta1 modulates the gating properties of the channel-forming type IIA alpha subunit, resulting in an acceleration of inactivation. We have used a combination of deletion, alanine-scanning, site-directed, and chimeric mutagenesis strategies to examine the importance of different structural features of the beta1 subunit in the modulation of alphaIIA function, with an emphasis on the extracellular domain. Deletion analysis revealed that the extracellular domain is required for function, but the intracellular domain is not. The mutation of four putative sites of N-linked glycosylation showed that they are not required for beta1 function. Mutations of hydrophobic residues in the core beta sheets of the Ig fold disrupted beta1 function, whereas substitution of amino acid residues in connecting segments had no effect. Mutations of acidic residues in the A/A' strand of the Ig fold reduced the effectiveness of the beta1 subunit in modulating the rate of inactivation but did not significantly affect the association of the mutant beta1 subunit with the alphaIIA subunit or its effect on recovery from inactivation. Our data suggest that the Ig fold of the beta1 extracellular domain serves as a scaffold that presents the charged residues of the A/A' strands for interaction with the pore-forming alpha subunit.

Both diacylglycerol (DAG) and phosphatidic acid (PA) are important second messengers involved in signal transduction from many immune cell receptors and can be generated and metabolized through multiple mechanisms. Recent studies indicate that diacylglycerol kinases (DGKs), the enzymes that catalyze phosphorylation of DAG to produce PA, play critical roles in regulating the functions of multiple immune cell lineages. In T cells, two DGK isoforms, alpha and zeta, inhibit DAG-mediated signaling following T-cell receptor engagement and prevent T-cell hyperactivation. DGK alpha and zeta synergistically promote T-cell anergy and are critical for T-cell tolerance. In mast cells, DGKzeta plays differential roles in their activation by promoting degranulation but attenuating cytokine production following engagement of the high affinity receptor for immunoglobulin E. In dendritic cells and macrophages, DGKzeta positively regulates Toll-like receptor-induced proinflammatory cytokine production through its product PA and is critical for host defense against Toxoplasma gondii infection. These studies demonstrate pivotal roles of DGKs in regulating immune cell function by acting both as signal terminator and initiator.

BACKGROUND

Recent studies have shown that both steroids and angiotensin-converting enzyme (ACE) inhibitors improve kidney survival and decrease proteinuria in patients with immunoglobulin A nephropathy. In this study, we aim to investigate whether the addition of steroids to ACE-inhibitor therapy produces a more potent antiproteinuric effect and better protection of kidney function than an ACE inhibitor alone.

METHODS

Randomized controlled trial.

METHODS

Patients with biopsy-proven immunoglobulin A nephropathy with proteinuria of 1 to 5 g/d of protein.

METHODS

63 patients were randomly assigned to either cilazapril alone (ACE-inhibitor group; n = 30) or steroid plus cilazapril (combination group; n = 33).

METHODS

The primary end point was kidney survival, defined as a 50% increase in baseline serum creatinine level.

RESULTS

After follow-up for up to 48 months, 7 patients in the ACE-inhibitor group (24.1%) reached the primary end point compared with 1 patient (3%) in the combination group. Kaplan-Meier kidney survival was significantly better in the combination group than the ACE-inhibitor group after 24 and 36 months (96.6% versus 75.7%, 96.6% versus 66.2%; P = 0.001). Urine protein excretion significantly decreased in patients in the combination group compared with the ACE-inhibitor group (time-average proteinuria, 1.04 +/- 0.54 versus 1.57 +/- 0.86 g/d of protein; P = 0.01). Multivariate analysis showed that combination treatment (hazard ratio, 0.1; 95% confidence interval, 0.014 to 0.946) and time-average proteinuria (hazard ratio, 14.3; 95% confidence interval, 2.86 to 71.92) were independent predictors of kidney survival.

CONCLUSIONS

Small sample size, a single center, and slight imbalances at baseline.

CONCLUSIONS

Our results suggest that the addition of steroid to ACE-inhibitor therapy provided additional benefit compared with an ACE inhibitor alone. However, this was a pilot study with a small number of participants achieving the end points, and thus further validation is necessary.

Glycosylation is the most abundant and complex protein modification, and can have a profound structural and functional effect on the conjugate. The oligosaccharide fraction is recognized to be involved in multiple biological processes, and to affect proteins physical properties, and has consequentially been labeled a critical quality attribute of biopharmaceuticals. Additionally, due to recent advances in analytical methods and analysis software, glycosylation is targeted in the search for disease biomarkers for early diagnosis and patient stratification. Biofluids such as saliva, serum or plasma are of great use in this regard, as they are easily accessible and can provide relevant glycosylation information. Thus, as the assessment of protein glycosylation is becoming a major element in clinical and biopharmaceutical research, this review aims to convey the current state of knowledge on the N-glycosylation of the major plasma glycoproteins alpha-1-acid glycoprotein, alpha-1-antitrypsin, alpha-1B-glycoprotein, alpha-2-HS-glycoprotein, alpha-2-macroglobulin, antithrombin-III, apolipoprotein B-100, apolipoprotein D, apolipoprotein F, beta-2-glycoprotein 1, ceruloplasmin, fibrinogen, immunoglobulin (Ig) A, IgG, IgM, haptoglobin, hemopexin, histidine-rich glycoprotein, kininogen-1, serotransferrin, vitronectin, and zinc-alpha-2-glycoprotein. In addition, the less abundant immunoglobulins D and E are included because of their major relevance in immunology and biopharmaceutical research. Where available, the glycosylation is described in a site-specific manner. In the discussion, we put the glycosylation of individual proteins into perspective and speculate how the individual proteins may contribute to a total plasma N-glycosylation profile determined at the released glycan level.

Streptococcus mitis is a viridans streptococcus and a normal commensal of the human oropharynx. However, S. mitis can escape from this niche and cause a variety of infectious complications including infective endocarditis, bacteraemia and septicaemia. It uses a variety of strategies to effectively colonize the human oropharynx. These include expression of adhesins, immunoglobulin A proteases and toxins, and modulation of the host immune system. These various colonization factors allow S. mitis to compete for space and nutrients in the face of its more pathogenic oropharyngeal microbial neighbours. However, it is likely that in vulnerable immune-compromised patients S. mitis will use the same colonization and immune modulation factors as virulence factors promoting its opportunistic pathogenesis. The recent publication of a complete genome sequence for S. mitis strain B6 will allow researchers to thoroughly investigate which genes are involved in S. mitis host colonization and pathogenesis. Moreover, it will help to give insight into where S. mitis fits in the complicated oral microbiome. This review will discuss the current knowledge of S. mitis factors involved in host colonization, their potential role in virulence and what needs to be done to fully understand how a an oral commensal successfully transitions to a virulent pathogen.

Eosinophils are multifunctional leukocytes that reside in the gastrointestinal (GI) lamina propria, where their basal function remains largely unexplored. In this study, by examining mice with a selective deficiency of systemic eosinophils (by lineage ablation) or GI eosinophils (eotaxin-1/2 double deficient or CC chemokine receptor 3 deficient), we show that eosinophils support immunoglobulin A (IgA) class switching, maintain intestinal mucus secretions, affect intestinal microbial composition, and promote the development of Peyer's patches. Eosinophil-deficient mice showed reduced expression of mediators of secretory IgA production, including intestinal interleukin 1β (IL-1β), inducible nitric oxide synthase, lymphotoxin (LT) α, and LT-β, and reduced levels of retinoic acid-related orphan receptor gamma t-positive (ROR-γt(+)) innate lymphoid cells (ILCs), while maintaining normal levels of APRIL (a proliferation-inducing ligand), BAFF (B cell-activating factor of the tumor necrosis factor family), and TGF-β (transforming growth factor β). GI eosinophils expressed a relatively high level of IL-1β, and IL-1β-deficient mice manifested the altered gene expression profiles observed in eosinophil-deficient mice and decreased levels of IgA(+) cells and ROR-γt(+) ILCs. On the basis of these collective data, we propose that eosinophils are required for homeostatic intestinal immune responses including IgA production and that their affect is mediated via IL-1β in the small intestine.

BACKGROUND

Systemic lupus erythematosus (SLE) is a highly heterogeneous disorder, characterized by differences in autoantibody profile, serum cytokines, and clinical manifestations. SLE-associated autoantibodies and high serum interferon alpha (IFN-α) are important heritable phenotypes in SLE which are correlated with each other, and play a role in disease pathogenesis. These two heritable risk factors are shared between ancestral backgrounds. The aim of the study was to detect genetic factors associated with autoantibody profiles and serum IFN-α in SLE.

METHODS

We undertook a case-case genome-wide association study of SLE patients stratified by ancestry and extremes of phenotype in serology and serum IFN-α. Single nucleotide polymorphisms (SNPs) in seven loci were selected for follow-up in a large independent cohort of 538 SLE patients and 522 controls using a multi-step screening approach based on novel metrics and expert database review. The seven loci were: leucine-rich repeat containing 20 (LRRC20); protein phosphatase 1 H (PPM1H); lysophosphatidic acid receptor 1 (LPAR1); ankyrin repeat and sterile alpha motif domain 1A (ANKS1A); protein tyrosine phosphatase, receptor type M (PTPRM); ephrin A5 (EFNA5); and V-set and immunoglobulin domain containing 2 (VSIG2).

RESULTS

SNPs in the LRRC20, PPM1H, LPAR1, ANKS1A, and VSIG2 loci each demonstrated strong association with a particular serologic profile (all odds ratios>> 2.2 and P < 3.5 × 10-4). Each of these serologic profiles was associated with increased serum IFN-α. SNPs in both PTPRM and LRRC20 were associated with increased serum IFN-α independent of serologic profile (P = 2.2 × 10-6 and P = 2.6 × 10-3 respectively). None of the SNPs were strongly associated with SLE in case-control analysis, suggesting that the major impact of these variants will be upon subphenotypes in SLE.

CONCLUSIONS

This study demonstrates the power of using serologic and cytokine subphenotypes to elucidate genetic factors involved in complex autoimmune disease. The distinct associations observed emphasize the heterogeneity of molecular pathogenesis in SLE, and the need for stratification by subphenotypes in genetic studies. We hypothesize that these genetic variants play a role in disease manifestations and severity in SLE.

The activation signal from tyrosine kinase receptors, such as the epidermal growth factor receptor (EGFR), is relayed via a highly conserved intracellular pathway involving Ras, Raf, and MAPK. In Drosophila, the EGFR and components of the intracellular pathway are broadly expressed, yet receptor activation evokes tissue-specific cell responses. Extracellular events that lead to receptor activation are one mechanism by which signaling is modulated. Here we show molecular and genetic evidence that Drosophila vein (vn) encodes a candidate EGFR ligand and that vn expression is spatially restricted. Consequently, vn may promote tissue-specific receptor activation. Unlike two other ligands, Gurken (Grk) and Spitz (Spi), which are transforming growth factor alpha-like proteins, Vn has both an immunoglobulin-like and an EGF-like domain. This combination of domains mirrors those in the vertebrate neuregulins that bind EGFR relatives.

One of the major difficulties in mining low abundance biomarkers from serum or plasma is due to the fact that a small number of proteins such as albumin, alphaimmunoglobulins, may represent as much as 80% of the total serum protein. The large quantity of these proteins makes it difficult to identify low abundance proteins in serum using traditional 2-dimensional electrophoresis. We recently used a combination of multidimensional liquid chromatography and gel electrophoresis coupled to matrix-assisted laser desorption/ionization-quadrupole-time of flight and Ion Trap liquid chromatography-tandem mass spectrometry to identify protein markers in sera of Alzheimer's disease (AD), insulin resistance/type-2 diabetes (IR/D2), and congestive heart failure (CHF) patients. We identified 8 proteins that exhibit higher levels in control sera and 36 proteins that exhibit higher levels in disease sera. For example, haptoglobin and hemoglobin are elevated in sera of AD, IR/D2, and CHF patients. The levels of several other proteins including fibrinogen and its fragments, alpha 2-macroglobulin, transthyretin, pro-platelet basic protein, protease inhibitors clade A and C, as well as proteins involved in the classical complement pathway such as complement C3, C4, and C1 inhibitor, were found to differ between IR/D2 and control sera. The sera levels of proteins, such as the 10 kDa subunit of vitronectin, alpha 1-acid glycoprotein, apolipoprotein B100, fragment of factor H, and histidine-rich glycoprotein were observed to be different between AD and controls. The differences observed in these biomarker candidates were confirmed by Western blot and the enzyme-linked immunosorbent assay. The biological meaning of the proteomic changes in the disease states and the potential use of these changes as diagnostic tools or for therapeutic intervention will be discussed.

The interferons are a family of cytokine mediators critically involved in alerting the cellular immune system to viral infection of host cells. Interferons not only exhibit important antiviral effects but also exert a key influence on the quality of the cellular immune responses and amplify antigen presentation to specific T cells. Type I interferon (IFN-alpha and IFN-beta) is secreted by virus-infected cells while type II, immune or gamma interferon (IFN-gamma) is mainly secreted by T cells, natural killer (NK) cells and macrophages. Interferons interact with specific cellular receptors, which promote production of second messengers ultimately leading to expression of antiviral and immune modulatory genes. The IFN genes themselves are regulated by transcriptional and posttranscriptional mechanisms including modulation by a family of interferon regulatory factors (IRFs) synthesised by host cells. IFNs activate macrophages, induce B cells to switch immunoglobulin type, alter T helper response, inhibit cell growth, promote apoptosis and induce an antiviral state in uninfected cells. The therapeutic potential of the IFNs is currently the focus of intense attention in a number of virus-associated diseases, tumours and autoimmune disorders.

A common residue numbering scheme for all immunoglobulin variable domains (immunoglobulin light chain lambda (V(lambda)) and kappa (V(kappa)) variable domains, heavy chain variable domains (V(H)) and T-cell receptor alpha (V(alpha)), beta (V(beta)), gamma (V(gamma)) and delta (V(delta)) variable domains) has been devised. Based on the spatial alignment of known three-dimensional structures of immunoglobulin domains, it places the alignment gaps in a way that minimizes the average deviation from the averaged structure of the aligned domains. This residue numbering scheme was applied to the immunoglobulin variable domain structures in the PDB database to automate the extraction of information on structural variations in homologous positions of the different molecules. A number of methods are presented that allow the automated projection of information derived from individual structures or from the comparison of multi-structure alignments onto a graphical representation of the sequence alignment.

BACKGROUND

The appropriate choice of an internal reference is critical for quantitative RNA analysis. However, no comparison of frequently used "housekeeping" genes is available for renal biopsy studies.

METHODS

Microdissected biopsies from 165 patients, including a wide range of histopathologic diagnoses, were analyzed [immunoglobulin A (IgA) nephritis, membranous glomerulopathy, rapid progressive glomerulonephritis, minimal change disease, focal segmental glomerulosclerosis (FSGS), nephrosclerosis, diabetic nephropathy, interstitial nephritis, and controls]. Expression of three frequently used housekeeping genes [glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 18S rRNA, and cyclophilin A] was examined by real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Absolute expression values of reference genes obtained from the renal biopsies were related to each other. In tubulointerstitial compartment, a positive correlation coefficient (r) of 0.96 was observed between 18S rRNA and cyclophilin A. However, a subset of samples showed lower expression levels for GAPDH in relation to 18S rRNA or cyclophilin A, resulting in a decrease to r = 0.77 and r = 0.73, respectively, consistent with considerable mRNA regulation of GAPDH. In glomerular samples, a comparable low correlation between GAPDH versus 18S rRNA (r = 0.75) was obtained.

CONCLUSIONS

Using a single housekeeper gene as reference for renal biopsy studies, differences in gene expression ratios may reflect regulation of the internal control rather than the mRNA under investigation. Relating the gene expression to several housekeepers in parallel (i.e., 18S rRNA and cyclophilin A) should result in robust expression data.

The serum antibody response of 50 infants and children infected with respiratory syncytial virus (RSV) was determined by a glycoprotein-specific enzyme-linked immunosorbent assay, and the effects of age and preexisting antibody titer at the time of RSV infection on response to the G and F glycoproteins of RSV were examined. The immune response to the G and F glycoproteins was assessed with anti-human immunoglobulin A to permit measurement of the response of young infants in the presence of maternally derived immunoglobulin G. The findings suggested that age primarily affects the response to the F glycoprotein and that preexisting antibody titer affects the response to the G glycoprotein.

Murine V<em>alpha</em>14 natural killer T (NKT) cells are thought to play a crucial role in various immune responses, including infectious, allergic, and autoimmune diseases. Because V<em>alpha</em>14 NKT cells produce large amounts of both interleukin (IL)-4 and interferon (IFN)-gamma upon in vivo stimulation with a specific ligand, <em>alpha</em>-galactosylceramide (<em>alpha</em>-GalCer), or after treatment with anti-CD3 antibody, a regulatory role on helper T (Th) cell differentiation has been proposed for these cells. However, the identity of the cytokine produced by V<em>alpha</em>14 NKT cells that play a dominant role on the Th cell differentiation still remains controversial. Here, we demonstrate by using V<em>alpha</em>14 NKT-deficient mice that V<em>alpha</em>14 NKT cells are dispensable for the induction of antigen-specific <em>immunoglobulin</em> (Ig)E responses induced by ovalbumin immunization or Nippostrongylus brasiliensis infection. However, upon in vivo activation with <em>alpha</em>-GalCer, V<em>alpha</em>14 NKT cells are found to suppress antigen-specific IgE production. The suppression appeared to be IgE specific, and was not detected in either V<em>alpha</em>14 NKT- or IFN-gamma-deficient mice. Consistent with these results, we also found that ligand-activated V<em>alpha</em>14 NKT cells inhibited Th2 cell differentiation in an in vitro induction culture system. Thus, it is likely that activated V<em>alpha</em>14 NKT cells exert a potent inhibitory effect on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-gamma. In marked contrast, our studies have revealed that IL-4 produced by V<em>alpha</em>14 NKT cells has only a minor effect on Th2 cell differentiation.

OBJECTIVE

To evaluate the use of tumor necrosis factor (TNF)-alpha blockade for treatment of patients with Kawasaki syndrome (KS) who fail to become afebrile or who experience persistent arthritis after treatment with intravenous gamma globulin (IVIG) and high-dose aspirin.

METHODS

Cases were retrospectively collected from clinicians throughout the United States who had used infliximab, a chimeric murine/human immunoglobulin (Ig)G1 monoclonal antibody that binds specifically to human TNF-alpha-1, for patients with KS who had either persistent arthritis or persistent or recrudescent fever>> or =48 hours following infusion of 2 g/kg of IVIG.

RESULTS

Response to therapy with cessation of fever occurred in 13 of 16 patients. C-reactive protein (CRP) level was elevated in all but one patient before infliximab infusion, and the level was lower following infusion in all 10 patients in whom it was re-measured within 48 hours of treatment. There were no infusion reactions to infliximab and no complications attributed to infliximab administration in any of the patients.

CONCLUSIONS

The success of TNF-alpha blockade in this small series of patients suggests a central role of TNF-alpha in KS pathogenesis. Controlled, randomized clinical trials are warranted to determine the role of anti-TNF-alpha therapy in KS.

There is increasing interest in the concept of using nanopores as the sensing elements in biosensors. The nanopore most often used is the alpha-hemolysin protein channel, and the sensor consists of a single channel embedded within a lipid bilayer membrane. An ionic current is passed through the channel, and analyte species are detected as transient blocks in this current associated with translocation of the analyte through the channel-stochastic sensing. While this is an extremely promising sensing paradigm, it would be advantageous to eliminate the very fragile lipid bilayer membrane and perhaps to replace the biological nanopore with an abiotic equivalent. We describe here a new family of protein biosensors that are based on conically shaped gold nanotubes embedded within a mechanical and chemically robust polymeric membrane. While these sensors also function by passing an ion current through the nanotube, the sensing paradigm is different from the previous devices in that a transient change in the current is not observed. Instead, the protein analyte binds to a biochemical molecular-recognition agent at the mouth of the conical nanotube, resulting in complete blockage of the ion current. Three different molecular-recognition agents, and correspondingly three different protein analytes, were investigated: (i) biotin/streptavidin, (ii) protein-G/immunoglobulin, and (iii) an antibody to the protein ricin with ricin as the analyte.

Mercury is an immunotoxic substance that has been shown to induce autoimmune disease in rodent models, characterized by lymphoproliferation, overproduction of immunoglobulin (IgG and IgE), and high circulating levels of auto-antibodies directed at antigens located in the nucleus (antinuclear auto-antibodies, or ANA) or the nucleolus (antinucleolar auto-antibodies, or ANoA). We have reported elevated levels of ANA and ANoA in human populations exposed to mercury in artisanal gold mining, though other confounding variables that may also modulate ANA/ANoA levels were not well controlled. The goal of this study is to specifically test whether occupational and environmental conditions (other than mercury exposure) that are associated with artisanal gold mining affect the prevalence of markers of autoimmune dysfunction. We measured ANA, ANoA, and cytokine concentrations in serum and compared results from mercury-exposed artisanal gold miners to those from diamond and emerald miners working under similar conditions and with similar socio-economic status and risks of infectious disease. Mercury-exposed gold miners had higher prevalence of detectable ANA and ANoA and higher titers of ANA and ANoA as compared to diamond and emerald miners with no occupational mercury exposure. Also, mercury-exposed gold miners with detectable ANA or ANoA in serum had significantly higher concentrations of pro-inflammatory cytokines IL-1beta, TNF-alpha, and IFN-gamma in serum as compared to the diamond and emerald miners. This study provides further evidence that mercury exposure may lead to autoimmune dysfunction and systemic inflammation in affected populations.

Voltage-gated sodium channels localize at high density in axon initial segments and nodes of Ranvier in myelinated axons. Sodium channels consist of a pore-forming alpha subunit and at least one beta subunit. beta1 is a member of the immunoglobulin superfamily of cell adhesion molecules and interacts homophilically and heterophilically with contactin and Nf186. In this study, we characterized beta1 interactions with contactin and Nf186 in greater detail and investigated interactions of beta1 with NrCAM, Nf155, and sodium channel beta2 and beta3 subunits. Using Fc fusion proteins and immunocytochemical techniques, we show that beta1 interacts with the fibronectin-like domains of contactin. beta1 also interacts with NrCAM, Nf155, sodium channel beta2, and Nf186 but not with sodium channel beta3. The interaction of the extracellular domains of beta1 and beta2 requires the region 169TEEEGKTDGEGNA181 located in the intracellular domain of beta2. Interaction of beta1 with Nf186 results in increased Nav).2 cell surface density over alpha alone, similar to that shown previously for contactin and beta2. We propose that beta1 is the critical communication link between sodium channels, nodal cell adhesion molecules, and ankyrinG.

Preformed immune aggregates, containing antigen and either IgG (immunoglobulin G) or F(ab')2 rabbit antibody, were incubated with normal human serum under conditions allowing activation of only the alternative pathway of complement. Both the IgG and F(ab')2 immune aggregates bound C3b, the activated form of the complement component C3, in a similar manner, 2-3% of the C3 available in the serum being bound to the aggregates as C3b, and the rest remaining in the fluid phase as inactive C3b or uncleaved C3. It was found that the C3b was probably covalently bound to the IgG in the aggregates, since C3b-IgG complexes could be demonstrated on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, after repeated washing with buffers containing high salt or boiling under denaturing conditions. Incubation of the C3b-antibody-antigen aggregates in buffers known to destroy ester linkages had little effect on the C3b-IgG complexes, which suggested that C3b and IgG might be linked by an amide bond. Two main types of C3b-IgG complexes were found that had apparent mol.wts. of 360000 and 580000, corresponding to either one to two C3b molecules respectively bound to one molecule of antibody. On reduction of the C3b-IgG complexes it was found that the beta-chain, but not the alpha'-chain, of C3b was released along with all the light chain of IgG but only about half or less of the heavy chain of IgG. These results indicate that, during activation of the alternative pathway of complement by immune aggregates containing IgG antibody, the alpha'-chain of C3b may become covalently bound at one or two sites in the Fd portion of the heavy chain of IgG.