Role Of Antibodies Research Articles

342: Obliterative Airway Disease (OAD) Induced by Antibodies to MHC-Class I Is B Cell Dependent: An Obligatory Role for Antibodies to Self Antigens in the Pathogenesis of OAD

342: Obliterative Airway Disease (OAD) Induced by Antibodies to MHC-Class I Is B Cell Dependent: An Obligatory Role for Antibodies to Self Antigens in the Pathogenesis of OAD

A case-control study of cutaneous squamous cell carcinoma among Caucasian organ transplant recipients: The role of antibodies against human papillomavirus and other risk factors

A case-control study of cutaneous squamous cell carcinoma among Caucasian organ transplant recipients: The role of antibodies against human papillomavirus and other risk factors

The role of antibodies in inflammatory arthritis

Inflammatory arthritis presents in a variety of diseases, from rheumatoid arthritis to hepatitis. Antibodies to autoantigens or to microbial constituents are commonly associated with these conditions. In some cases, the antibodies have diagnostic and prognostic relevance. It cannot as yet be determined definitively that any of them mediate joint damage, although the evidence from animal models indicates that this mechanism is likely. The purpose of this article is to give an overview of the spectrum of antibodies found in a variety of inflammatory arthritides. The relevant animal models are also discussed.

Immunological Challenges of Cardiac Transplantation: The need for Better Animal Models to Answer Current Clinical Questions

In the last decade, two advances have shifted attention from cellular rejection to antibody-mediated rejection (AMR) of cardiac transplants. First, more sensitive diagnostic tests for detection of AMR have been developed. Second, improvements in immunosuppression have made severe acute cellular rejection uncommon, but have had less effect on AMR. Antibodies can contribute to graft rejection by activation of complement, by activation of vascular endothelial and smooth muscle cells, and by activation of neutrophils, macrophages or natural killer cells. Because acute rejection is a risk factor for chronic rejection in all types of organ transplants, it is has been proposed that AMR can cause chronic rejection. Small animal models need to be developed to gain further insights into AMR and the role of antibodies in chronic graft arteriopathy. This article reviews the current clinical data and existing mouse models for AMR.

Prediction of radiographic progression in rheumatoid arthritis and the role of antibodies against mutated citrullinated vimentin: results from a 10-year prospective study

Objectives:Anti-citrullinated peptide antibodies (ACPAs) are established as useful predictors of radiographic progression in rheumatoid arthritis (RA). The main objective of this study was to test the prognostic capacity of the...

A case‐control study of cutaneous squamous cell carcinoma among Caucasian organ transplant recipients: The role of antibodies against human papillomavirus and other risk factors

A case-control study was conducted in 140 people with histology proven cutaneous squamous cell carcinoma (SCC) and 454 controls, nested within 2 cohorts of organ transplant recipients (OTR) recruited in London and Oxford between 2002 and 2006. All participants had a skin examination, completed a questionnaire and had serum tested for antibodies against the L1 antigen of 34 HPV types using Luminex technology. SCC was more common in men than women (odds ratio [OR] = 1.7, 95% confidence interval [CI]: 1.1-2.8, p = 0.02) and in people with susceptibility to burn easily (OR = 3.0, 95%CI: 1.9-4.8; p < 0.001). The risk increased with increasing age (p-trend < 0.001), increasing time since transplant (p-trend < 0.001), increasing self-reported number of sunburns as a child (p-trend < 0.001) and with the presence of viral warts (p < 0.001). As expected, antibodies against HPV 16 were associated with a self-reported history of an abnormal cervical smear among women (OR 5.1, 95%CI: 2.6-10.2) and antibodies against HPV 6 were associated with a self-reported history of genital warts (OR 4.0, 95%CI: 2.2-7.2). However, no clear associations between any of the HPV types examined (including cutaneous betaHPVs) and SCC were identified. For example, the seroprevalence of HPV 5 was 15% among cases and 9% among controls (p = 0.09) and the seroprevalence of HPV 8 was 23% among cases and 21% among controls (p = 0.6). Nor was seropositivity to multiple types associated with SCC. These serological data do not provide evidence for a role for HPV in the aetiology of cutaneous SCC among OTR in two UK-based populations.

Effects of Blood Transfusions Given After Renal Transplantation

Human leukocyte antigen (HLA) antibodies produced after transplantation are frequently measured in transplant recipients, because they are strongly associated with humoral rejection and graft loss. However, antibodies can be induced by posttransplant blood transfusions rather than by the graft, casting doubts about the possible role of antibodies in a patient with graft dysfunction. We recorded the posttransplant transfusions in 746 patients transplanted during a 6-year period. Rejection episodes were evaluated after exclusion of patients who were transfused proximate to the time of rejection. Specimens for solid-phase HLA antibody testing were available in 199 patients. The frequency of transfusions was 45%, but it was higher in deceased donor transplants (51%) than in live donor transplants (30%). Almost 80% of the transfusions were given during the first month after transplant. However, the incidence of posttransplant antibodies was similar in patients transfused and not transfused, and only 1 of 12 patients who received more than 10 transfusions produced antibodies. There was no evidence that posttransplant antibodies not directed to donor antigens were triggered by transfusions. The incidence of rejection episodes, allograft nephropathy, and graft loss was slightly more in transfused patients but the differences were not statistically significant. When HLA antibodies are detected posttransplant, they are likely induced by the graft rather than by any transfusions the patient may have received. The results suggest that posttransplant transfusions do not have the sensitizing or down-regulatory effects of pretransplant transfusions.

Antibody-mediated immunity to the obligate intracellular bacterial pathogen Coxiella burnetii is Fc receptor- and complement-independent

BackgroundThe obligate intracellular bacterial pathogen Coxiella burnetii causes the zoonosis Q fever. The intracellular niche of C. burnetii has led to the assumption that cell-mediated immunity is the most important immune component for protection against this pathogen. However, passive immunization with immune serum can protect naïve animals from challenge with virulent C. burnetii, indicating a role for antibody (Ab) in protection. The mechanism of this Ab-mediated protection is unknown. Therefore, we conducted a study to determine whether Fc receptors (FcR) or complement contribute to Ab-mediated immunity (AMI) to C. burnetii.ResultsVirulent C. burnetii infects and replicates within human dendritic cells (DC) without inducing their maturation or activation. We investigated the effects of Ab opsonized C. burnetii on human monocyte-derived and murine bone marrow-derived DC. Infection of DC with Ab-opsonized C. burnetii resulted in increased expression of maturation markers and inflammatory cytokine production. Bacteria that had been incubated with naïve serum had minimal effect on DC, similar to virulent C. burnetii alone. The effect of Ab opsonized C. burnetii on DC was FcR dependent as evidenced by a reduced response of DC from FcR knockout (FcR k/o) compared to C57Bl/6 (B6) mice. To address the potential role of FcR in Ab-mediated protection in vivo, we compared the response of passively immunized FcR k/o mice to the B6 controls. Interestingly, we found that FcR are not essential for AMI to C. burnetii in vivo. We subsequently examined the role of complement in AMI by passively immunizing and challenging several different strains of complement-deficient mice and found that AMI to C. burnetii is also complement-independent.ConclusionDespite our data showing FcR-dependent stimulation of DC in vitro, Ab-mediated immunity to C. burnetii in vivo is FcR-independent. We also found that passive immunity to this pathogen is independent of complement.

M2033 Role of Antibodies in the Long Term Follow Up of Patients with Celiac Disease to Predict the Adherence to Gluten-Free Diet

Introduction: The prevalence of celiac disease (CD) is 0.5-1% in the Western population. As CD is widely underdiagnosed, the majority of CD patients is still untreated and therefore at greater risk of developing complicated CD, including Enteropathy Associated T-cell Lymphoma (EATL). Differentiation between various T-cell lymphomas is difficult because of similar morphology and immunophenotype. The final diagnosis is based on clinical presentation and localisation of the lymphoma. Consequently, T-cell lymphomas in CD patients and T-cell lymphomas in the small bowel are always diagnosed as EATLs. However, 25% of EATLs are located extra-intestinal. The most frequent type of T-cell lymphomas is anaplastic large cell lymphoma (ALCL). ALCLs are either anaplastic lymphoma kinase (ALK) negative or positive. EATLs are always ALK negative. As is the case for most EATLs, ALCLs are CD30 positive. CD and EATL are strongly associated with HLA-DQ2 and/or -DQ8. HLADQ2 and/or -DQ8 expression is found in 98% of CD and EATL patients, compared to 40% in the Western population. Aims and Methods: We investigated whether the frequency of HLA-DQ2 and/or -DQ8 is increased in extra-intestinal ALCLs compared to the general population, in order to determine if extra-intestinal ALCLs might in fact be undiagnosed EATLs. For this purpose, extra-intestinal ALCL samples, ALK-positive and ALK-negative, were collected and DNA was isolated. DQA1 and DQB1 alleles were amplified using PCR. HLA-DQ typing was subsequently performed using a single strand conformation polymorphism / heteroduplex based method (SSCP/HD). Results: So far, 21 anaplastic large-cell lymphomas have been HLA-DQ typed. HLA-DQ2 was present in 10 lymphomas, of which 3 were homozygous. HLA-DQ8 was present in 4 lymphomas, all heterozygous. In total, twelve lymphomas (57%) were HLA-DQ2 and/or -DQ8 positive, indicating only a slightly higher prevalence than in the general population. However, within the subgroup of ALKnegative ALCLs, representing potentially undiagnosed EATLs, 71% was HLA-DQ2 and/or DQ8 positive (p=0.05). Conclusion: The increased prevalence of HLA-DQ2 and/or -DQ8 in ALK-negative ALCLs suggests underdiagnosis of EATL within this group of extra-intestinal T-cell lymphomas.

Role of antibodies in controlling dengue virus infection

The incidence and disease burden of arthropod-borne flavivirus infections have dramatically increased during the last decades due to major societal and economic changes, including massive urbanization, lack of vector control, travel, and international trade. Specifically, in the case of dengue virus (DENV), the geographical spread of all four serotypes throughout the subtropical regions of the world has led to larger and more severe outbreaks. Many studies have established that recovery from infection by one DENV serotype provides immunity against that serotype, whereas reinfection with another serotype may result in severe disease. Pre-existing antibodies thus play a critical role in controlling viral infection. Both neutralization and enhancement of DENV infection by antibodies are thought to be related to the natural route of viral entry into cells. In this review, we will describe the current knowlegde on the mechanisms involved in flavivirus cell entry and discuss how antibodies may influence the course of infection towards neutralization or enhancement of viral disease.

Development of a three-dimensional model of lung cancer using cultured transformed lung cells

Despite great strides in understanding cancer biology, the role cellular differentiation and three-dimensional (3-D) structural organization play in metastasis and malignancy remains unclear. Development of 3-D cultures may ultimately provide a model facilitating discovery and interpretation of more relevant information for the expression and role of antibodies in lung cellular pathobiology. The purpose was to develop traditional monolayer (ML) and 3-D cultures of a known transformed metastatic lung cell line and then determine similarities and differences between cultures in terms of differentiation, molecular marker expression and metastasis. A transformed lung cell line (BZR-T33) was initially transfected with green fluorescent protein (GFP) in ML culture. Nude mice were inoculated with BZR-T33 and observed for metastasis. BZR-T33 was grown as ML and 3-D cultures under identical conditions. Immunohistochemical comparison for degree of antibody expression between cultures and control tissue were studied. Electron microscopy (EM) for identification of ultra structures was done and compared between cultures. A 3-D co-culture containing GFP-transformed cells over an immortalized lung-cell line was developed. The GFP-transfected cell line formed tumors and metastasized in mice. EM identified significant mitochondrial and granular endoplasmic reticular pathology in ML not seen in 3-D. Degree of differentiation shows ultra structures and antibody expressions were more representative of control tissue in 3-D than ML. The co-culture experiment in 3-D demonstrates the ability of transformed cells to penetrate the sub-layer of immortalized cells. Development of 3-D cultures will provide a new and powerful tool to study lung biology and pathobiology.

A Good Vaccine Is Hard to Find: Nonprofit Biotechs Tackle Tuberculosis

The Aeras Global TB Vaccine Foundation was founded in 2003 as a spinoff of Maryland BIOTECH Sequella. The 130 person nonprofit biotech intends to develop a TB vaccine by 2016. “The word everybody uses in the nonprofit TB drug field is accessibility,” said Peg Willingham. “People have got to afford them, or have somebody pay for them, so that they can afford the therapies.”In 2007, The Gates Foundation awarded Aeras $200 million over 5 years to push a TB vaccine through phase II, building on a 2003 grant. Aeras estimates it will cost $120 million to bring a TB vaccine candidate to phase III trials. Aeras has six vaccine candidates in the pipeline, two in preclinical, two in phase I/II, and one in phase II.“Our ideal would be a vaccine that would prevent initial infection and later reinfection,” said Willingham. “At a minimum … it should be 60% effective. No vaccines on the market are 100% effective.” Production has to scale very cheaply to 100 million doses a year. To that end, Aeras has its own in-house vaccine manufacturing facility.“Our strategy is called a prime boost strategy,” said Dr. Lewellys Barker, senior medical advisor. Aeras is developing an improved BCG vaccine for newborns. According to Barker, BCG is a live vaccine, and Aeras's goal is to modify it so it overexpresses certain antigens to make it safer, particularly for patients with HIV. Long-term follow-up studies suggest that TB vaccine protection doesn't last, so a booster is necessary.Aeras, along with Nevada-based Crucell, has developed AERAS-402/Crucell Ad35, a replication-deficient adenovirus that expresses TB antigens meant to elicit high levels of CD8+ T cell responses. AREAS-402/Crucell AD35 completed a phase I clinical trial in the US in 2006. Another phase I trial started in South Africa in 2007 in healthy adults vaccinated at birth with BCG.Aeras is currently partnering with the South African Tuberculosis Vaccine Initiative of the University of Capetown (http://www.satvi.edu) to test the Oxford University MVA viral-vector vaccine. According to Willingham, South Africa has good technical capabilities and infrastructure. It also has a high rate of endemic TB, which is necessary for testing the vaccine in large and varied populations to get significant data. Aeras also has agreements in Kenya, India, Uganda, and Cambodia.“First we have to get a vaccine that works well,” said Barker. “And that is the challenge in TB. We don't know what kind of immune response we need to get for a recipient to be protected.” According to Barker, cell-mediated responses are thought to be important, but the role of antibodies is unknown. A major accomplishment will be the ability to gauge T cell responses. “Aside from a better regime for immunizing against TB, we would like it to work for people infected with HIV,” Barker said.Aeras also has a few preclinical projects: an oral vaccine using a bacteriophage capsid inserted in attenuated shigella bacteria as well as an inhaled vaccine being tested on animals at Tulane University in New Orleans. Barker noted that it is uncertain whether animal tests could predict vaccine performance in people or what would be the indication of the immune response needed for animals. Researchers do not know what immune response is needed to judge the effectiveness of early childhood immunization. “Clinical testing will be difficult, as diagnosis of TB in early childhood is difficult,” said Barker.“We have relatively little drug-resistant TB in this country, but this not really true in the rest of the world,” said Barker.

Structural studies of West Nile virus in complex with neutralizing antibodies

West Nile virus (WNV) is a positive strand RNA virus in the family Flaviviridae, which includes members such as dengue, Japanese encephalitis, tick-borne encephalitis, yellow fever and Hepatitis C. As with other members of the genus, it is arthropod transmitted and has recently established itself as an endemic virus in the United States. Although most infections are asymptomatic, clinical manifestations of WNV include encephalitis and death. We have been interested in investigating the nature of the immune response with particular emphasis on the role of antibodies in reducing the level of infection. We have used a combination of techniques, but primarily structure, as a tool to probe the nature of antibody-mediated virus neutralization. Our results suggest that neutralization of virus particles is more complex than originally envisioned, with multiple mechanisms utilized. Using a combination of Xray crystallography and cryo-electron microscopy, several virus-antibody complexes have been determined at pseudo-atomic resolution. These studies suggest the following: 1) flavivirus particles exhibit dynamic motions or breathing that transiently expose cryptic epitopes; 2) although there are 180 potential binding sites for each monoclonal antibody the quasi-equivalent nature of the virion usually permits only a subset of sites to be utilized; 3) the availability of these sites, the epitope itself, and the avidity of antibody directly influence the mechanism of neutralization; and 4) particles thought to be incapable of infecting cells, so-called immature viruses, may play a critical role in immune surveillance and reactivity. The structure of the flavivirus virion and complexes of monoclonal antibodies will be presented along with data to support mechanisms antibody-mediated flavivirus neutralization. from Infectious diseases of the nervous system: pathogenesis and worldwide impact Paris, France. 10–13 September 2008

The role of antibodies to mutated citrulinated vimentin (anti-MCV) in juvenile idiopathic arthritis patients

Anti-MCV antibodies (Ab) have high sensitivity and prognostic value in patients with RA. We attempt to correlate positive anti-MCV Ab in different subtypes of JIA patients with six core outcome variables. Anti-MCV Ab and Anti-CCP Ab were tested by ELISA (Orgentec, Germany) in sera from 57 JIA, and 14 control patients (12 patients with SLE, 1 with MCTD and 1 with synovial cyst). (16 boys, 41 girls), The mean age was 11, 2 years (range 2, 5– 18, 0), and mean disease duration was 3, 4 years (SD ± ; 2.9). Cut off value ≥ 20 U/mL was considered positive. Positive anti-MCV Ab were detected in only 3/58 (5, 2%) JIA patients, and were significantly elevated in two RF positive polyartritis patients, and slightly elevated in 1/19 (5, 3%) patients with enthesitis-related arthritis (ErA). Among all patients, anti-CCP Ab were positive only in one anti-MCV positive polyarticular JIA patient. Anti-MCV and RF positivity correlated statistically (r = 0, 504, P = 0, 028) in ErA, while no association between anti-MCV Ab and six core outcome variables was observed in this, or other JIA subtypes. Unexpectedly, anti-MCV was detected in 3/12 (25%) SLE patients (2 low positive and 1 significantly positive), and in 1 patient with MCTD. All of these patients were both RF and anti-CCP negative. In contrast to RA, anti-MCV antibodies are not specific for JIA. However, within JIA patients, significantly elevated levels are almost exclusively found in two RF positive, polyarticular patients.

Adhesion of Escherichia coli in urinary tract infection.

In individuals prone to urinary tract infections the intestine is colonized by E. Coli strains that possess a combination of properties determining virulence. Such an E. coli strain may colonize the vaginal and periurethral area and ascend the urinary tract. The ability to attach to the mucosal surface is thought to be essential for E. coli to colonize and to remain in the urinary tract. Most E. coli from patients with urinary tract infection show one or both of two adherence properties. One may depend on the recognition by type 1 fimbriae of mannose-containing residues in the urinary slime. It is measured as mannose-sensitive haemagglutination and is found on most E. coli strains. The second adherence property is detected as attachment to human urinary tract epithelial cells and as mannose-resistant agglutination of human erythrocytes. This may depend on the recognition of globo-series glycolipids in the epithelial cell surface. Possession of this adherence factor is strongly related to virulence. Most strains from patients with acute pyelonephritis and cystitis have this property but it is rare in strains from patients with asymptomatic bacteriuria and strains from normal faeces. Local antibodies may interfere with bacterial attachment, thus possibly preventing the colonization that precedes urinary tract infection or modifying an established infection. Vaginal antibodies are known to coat E. coli from the stools. Antibodies in the urine of patients with acute pyelonephritis inhibit attachment of the infecting strain to uroepithelial cells. Antibodies directed against several bacterial surface structures, for example O antigen and fimbriae, are likely to inhibit attachment by steric hindrance or agglutination. The role of antibodies in adhesion-mediating structure such as fimbriae in susceptibility to and the outcome of human urinary tract infection remains to be investigated.

Intrathecal antibody production in the Theiler's murine encephalomyelitis model of multiple sclerosis

Objective: To assess the role of intrathecal antibody production (ITAbP) in a murine model of multiple sclerosis(MS).Background: ITAbP is a hallmark of MS, but is poorly understood. Infection of mice with Theiler's murine encephalomyelitis virus (TMEV) results in a progressive disabling demyelinating disease resembling MS, but the role of antibody in central nervous system(CNS) injury in this model is unknown.Design/Methods: ITAbP in TMEV‐induced demyelinating disease(TMEV‐IDD) was measured using ELISpot for IgG‐producing cells and RT‐PCR for IgG1 mRNA, viral load was determined by RT‐PCR for TMEV RNA, and CNS injury was measured by Rotarod analysis of infected mice. Demyelination and immunoglobulin deposition were assayed histologically in the spinal cord by luxol fast blue and immunofluorescent staining, respectively.Results‐Robust ITAbP was present in 85% of infected mice and correlated positively with CNS injury and viral load. Demyelination and immunoglobulin deposition in injured tissue was prominent in mice with ITAbP.Conclusions/Relevance: ITAbP and immunoglobin deposition is highly associated with CNS injury in a murine viral model of MS. These data provide evidence that intrathecally produced antibody may contribute to CNS injury.

Therapeutic Antibodies in Multiple Sclerosis

ment of ever more effective drugs for the treatment of MS. The first immunomodulatory agents to benefit from the development mentioned above, interferon(Avonex , Betaferon/Betaseron , Rebif ) and glatiramer acetate (Copaxone ), have been on the market for more than a decade now and are established, safe, yet only mildly effective treatments for MS. They reduce the frequency of new relapses by 30–40%, and their effect on disease progression has remained controversial. Additionally, the necessity to self-inject these drugs in intervals between once daily (Copaxone ) to once weekly (Avonex ), as well as common side effects, such as flu-like symptoms and injection site reactions, limit patient compliance to some degree. Numerous researchers have demonstrated that both interferonand glatiramer acetate exert ‘pleiotropic effects’ on the immune system and the CNS, while essentially leaving the question unanswered as to which of these multiple modes of action are central in treating MS. In contrast, antibodies, in principal a natural component of the immune system, constitute a different kind of therapeutic agents, which can interact with precisely defined targets. This issue of Neurodegenerative Diseases focuses on the role of antibodies as a therapy for MS. The article by Soelberg Sorensen is dedicated to a truly ‘natural’ human antibody preparation: these so-called ‘intravenous immunoglobulins’ are polyclonal human antibodies isolated from the pooled plasma of thousands of human donors. Intravenous immunoglobulins contain the normal humoral immune repertoire and have been Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system (CNS). MS commonly strikes young adults, exposing them to an uncertain future dimmed by neurological impairment. In spite of immense research efforts in the last decades, there is still no cure for MS. In fact, the cause of MS, leading to variable degrees of inflammation, demyelination and axonal damage in the CNS, is enigmatic. While a strong genetic predisposition is established, environmental factors, possibly infectious agents encountered during childhood and puberty, seem to play an equally important role. Until the early 1990s, immunosuppressive agents like azathioprine were the mainstay of MS treatment. Since then, MS therapy has dramatically changed. New immunobiological findings and pathophysiological concepts as well as advances in biotechnology lead to the identification of a variety of potential therapeutic targets. Improvements in clinical trial design and the development of magnetic resonance imaging have made it possible to objectively quantify the therapeutic benefit of new treatment modalities in a disease as heterogeneous and unpredictable as MS. Also, both society and health insurances have recognized that prevention or delay of neurological impairment in MS patients is important and may be cost effective even in spite of the high prices of modern immunomodulatory drugs, when taking into account the reduced quality of life and the enormous secondary costs due to disability. This in return has made it worthwhile for pharmaceutical companies to invest in the developD i s e a s e s

Congenital and acquired toxoplasmosis: diversity and role of antibodies in different compartments of the host

The apicomplexan parasite Toxoplasma gondii is remarkable in several aspects, since it is a protozoan that infects most nucleated cells in many warm-blooded animals, worldwide. Although the cellular immune response against T. gondii is critical for infection control, antibodies may either enhance or block protective mechanisms, and even mediate immunological damage, directly or indirectly. Since cytokines regulate the class/subclass switch, antibodies may also be the biomarkers of protective or pathological cellular immune events. There is a scientific and clinical interest in the presence of natural and autoreactive antibodies, as well as in the 'chronic' immunoglobulin M (IgM) response and the post-treatment 'rebound'. Another interesting aspect is compartmentalization; certain immunoglobulins may uniquely be found in specific host fluids. Local synthesis has been demonstrated, but antibodies may also traverse several cell layers, like the blood-brain and haemato-ocular barriers, and the placenta. In some instances, Fc receptors (FcRs) facilitate transport and may even have a concentrator effect, which can be related to resistance or pathology. These aspects of the humoral response against T. gondii are reviewed in the present paper.

Systematic analysis of longitudinal serological responses of pigs infected experimentally with African swine fever virus

The protective immune response to African swine fever virus (ASFV) includes both cellular and serological components. In this study, the role of antibodies in the pathogenicity and diagnosis of African swine fever (ASF) was explored. Accordingly, total and Ig isotype antibody responses against the 12 viral proteins previously demonstrated to be the main targets of serological immunity were evaluated in longitudinally collected sera from pigs infected experimentally with the non-pathogenic ASFV/NH/P68 isolate. Strong total IgG antibody responses were observed against viral proteins E183L/p54, K205R/'unassigned', A104R/histone-like and B602L/'unassigned'; therefore, IgM, IgG1 and IgG2 responses to these proteins were also determined. One protein stimulating IgM (K205R) may have practical potential for the detection of recently infected animals. There was a clear trend towards an IgG1 response to all of the proteins. This may reflect a dominant Th2-controlled immune response. In order to identify possible correlations between these serological responses and the pathogenesis of ASF, total IgG responses to the 12 recombinant proteins were compared in asymptomatic and chronically infected animals. For the proteins NP419L/DNA ligase, CP312R, B646L/p73, K196R/thymidine kinase and K205R, the antibody titres were significantly higher in animals developing lesions. One exception was the antibody response to the A104R/histone-like protein, which was higher in asymptomatic than in chronically infected pigs, suggesting that antibodies against this protein might be an indicator of an effective immune response or that this response is somehow involved in protection.

Construction of miniantibodies for the in vivo study of human autoimmune diseases in animal models

BackgroundPhage display antibody libraries have been made from the lymphocytes of patients suffering from autoimmune diseases in which the antibodies are known to play a role in the pathogenesis or are important for the diagnosis of the disease. In the case of Celiac Disease, the immune response is directed against the autoantigen tissue transglutaminase. However, despite numerous studies, the role of these antibodies in the pathogenesis of this disease has not been elucidated.ResultsWe were able to engineer specific anti-transglutaminase antibody fragments in the form called "miniantibody". These are produced by genetic fusion of anti-tTG scFv to Human, Mouse or Rat Fc domains, making them suitable for in vivo expression. The results obtained here indicate that the miniantibody molecule is efficiently secreted, and that the reactivity to the antigen is retained even after fusion to heterologous Fc domains. Further analysis demonstrate that the molecule is secreted as homodimeric, mimicking original antibody structure. Finally, the in vivo expression in mice leads to detectable serum levels with no apparent gross immune response by the host.ConclusionIn this work we demonstrated the usefulness of a method for the in vivo expression of miniantibodies specific to transglutaminase, corresponding to the autoimmune specificity of Celiac Disease. This can be proposed as a general method to study the pathogenic role of autoimmune antibodies in autoimmune diseases.