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Biomedical subjects

S Albani

Publications and source records attributed to S Albani.

At least 19 recordsLinked to original sources
PubMed2003

Heat shock proteins (HSP) for immunotherapy of rheumatoid arthritis (RA).

Rheumatoid arthritis (RA) is an inflammatory disease that primarily involves the joints and has a worldwide prevalence of about one percent, with a female to male ratio of 3:1. This chapter summarizes some of the recent progress in molecular immunology, and discusses the application of this new knowledge for therapeutic purposes. We focus on our recent experiences and that of others in modulation of antigen specific responses as a tool for manipulating autoimmune inflammation. Particular emphasis is given to the concept of exploiting for therapeutic purposes a natural mechanism of immune regulation. This mechanism is based on sequential cross recognition of bacterial and human derived heat shock protein peptides.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

A genomewide screen in multiplex rheumatoid arthritis families suggests genetic overlap with other autoimmune diseases.

Rheumatoid arthritis (RA) is an autoimmune/inflammatory disorder with a complex genetic component. We report the first major genomewide screen of multiplex families with RA gathered in the United States. The North American Rheumatoid Arthritis Consortium, using well-defined clinical criteria, has collected 257 families containing 301 affected sibling pairs with RA. A genome screen for allele sharing was performed, using 379 microsatellite markers. A nonparametric analysis using SIBPAL confirmed linkage of the HLA locus to RA (P < .00005), with lambdaHLA = 1.79. However, the analysis also revealed a number of non-HLA loci on chromosomes 1 (D1S235), 4 (D4S1647), 12 (D12S373), 16 (D16S403), and 17 (D17S1301), with evidence for linkage at a significance level of P<.005. Analysis of X-linked markers using the MLOD method from ASPEX also suggests linkage to the telomeric marker DXS6807. Stratifying the families into white or seropositive subgroups revealed some additional markers that showed improvement in significance over the full data set. Several of the regions that showed evidence for nominal significance (P < .05) in our data set had previously been implicated in RA (D16S516 and D17S1301) or in other diseases of an autoimmune nature, including systemic lupus erythematosus (D1S235), inflammatory bowel disease (D4S1647, D5S1462, and D16S516), multiple sclerosis (D12S1052), and ankylosing spondylitis (D16S516). Therefore, genes in the HLA complex play a major role in RA susceptibility, but several other regions also contribute significantly to overall genetic risk.

Alleles↗
PubMed2000

Cell-mediated DNA transport between distant inflammatory sites following intradermal DNA immunization in the presence of adjuvant.

After intradermal genetic immunization, naked DNA is transported from the site of injection to regional lymph nodes. Little is known on how inflammation influences this process and whether DNA is transported beyond local lymph nodes. In the experiments herein reported, we injected naked DNA in the presence of adjuvant to address questions related to 1) the fate of naked DNA in the presence of inflammation; 2) the generation of immune responses to the encoded protein during inflammation; and, more in general, 3) the fate of ingested molecules beyond regional lymph nodes during inflammation. Two sites of inflammation were induced in vivo in mice. Naked DNA was injected in the nape together with adjuvant, and adjuvant only was injected at a distant peritoneal site. Injected DNA, uptaken at the primary dermal site of inflammation, was transported beyond regional lymph nodes to distant organs such as the spleen and to the distant peritoneal site of inflammation. This transport, mediated by CD11b+ cells, was cumulative during chronic inflammation. These results indicate a novel route of transport of DNA beyond regional lymph nodes and may have specific implications for DNA-based immune modulation.

Adjuvants, Immunologic↗
PubMed2000

Genetic immunization for the recovery and purification of recombinant proteins.

A system that uses genetic immunization for recombinant protein recovery and purification is described. The genetic sequence encoding a target protein is subcloned into both a eukaryotic and a prokaryotic vector. With the eukaryotic construct, a rabbit is genetically immunized and specific polyclonal antibodies to the encoded protein raised. The prokaryotic construct is used for bacterial transformation and expression of recombinant protein. Recovery and purification of target recombinant protein are obtained by passing the lysate of expressing bacteria through an immunoaffinity column prepared with the polyclonal antibodies raised in the genetically immunized animal. This method allows purification of recombinant protein without fusion tails and can be applied to purify any protein whose encoding genetic sequence is known.

Animals↗
PubMed2000

Artificial antigen-presenting cells as a tool to exploit the immune 'synapse'.

Recent progress in molecular medicine has provided important tools to identify antigen-specific T cells. In most cases, the approach is based on oligomeric combinations of recombinant major histocompatibility complex-peptide complexes fixed to various rigid supports available for binding by the T-cell receptor. These tools have greatly increased our insight into mechanisms of immune responses mediated by CD8+ T cells. Examples of the diverse fields of application for this technology include immunization, viral infections and oral tolerance induction.

Antigen Presentation↗
PubMed1999

Ontogeny of synonymous T cell populations with specificity for a self MHC epitope mimicked by a bacterial homologoue: an antigen-specific T cell analysis in a non-transgenic system.

By means of a novel technique for identification and isolation of MHC class II-restricted antigen-specific T cells, we describe here in non-transgenic BALB / c mice physiological positive selection of an oligoclonal population of T cells which recognizes both a self MHC-derived peptide (Ialpha52) and a bacterial homologoue (Hi15). The results support a model for self peptide-mediated generation of T cells which have specificity for microbial antigens through molecular mimicry. This mechanism may be a model for the ontogeny of a physiological T cell response to infectious agents. Loss of control of these circuits may be part of the inciting factors of autoimmunity.

Animals↗
PubMed1999

Isolation of an IgG monoclonal anti-dnaJ antibody from an immunoglobulin combinatorial library from a patient with rheumatoid arthritis.

OBJECTIVE: Previously, we showed that rheumatoid arthritis (RA) had both antibodies and T cells specific for the QKRAA-encompassing Escherichia coli dnaJ protein. These findings suggest that the bacteria induced anti-dnaJ responses may cross react with the human homolog of bacterial dnaJ in the joint, resulting in tissue damage. METHODS: We used the combinatorial library technique to isolate and characterize an IgG monoclonal anti-dnaJ antibody (designated CG1) from the blood of a patient with RA. RESULTS: Sequence analysis of CG1 revealed that its heavy and light chain V regions were respectively most homologous to the 3d279d VH4 and the O18 Vk1 genes. Interestingly, 3d279d is frequently expressed by B cells stimulated with staphylococcal enterotoxin; and O18 is the main gene employed by the Vk1 IgG antibodies against Haemophilus influenzae. CONCLUSION: The combinatorial immunoglobulin library method represents an interesting model of how to approach the isolation and characterization of antibody-like reagents in the elucidation of autoantigens in RA.

Amino Acid Sequence↗
PubMed1998

Mucosal modulation of immune responses to heat shock proteins in autoimmune arthritis.

Induction of oral tolerance to antigens that are targets of self-reactive immune responses is an attractive approach to antigen-specific immune therapy of autoimmune diseases. Oral tolerization has indeed proven to be safe and effective in amelioration of autoimmune diseases in animal models. In humans, results have been somewhat controversial. The emphasis given to clinical outcome rather than to immunomodulation, and the difficulty in identifying appropriate candidate antigens contribute to the controversy. Heat shock proteins are promising targets for immune intervention. Immune reactivity to heat shock proteins has indeed been correlated with autoimmune arthritis in animal models, and abnormal immune responses to heat shock proteins have been described in human arthritis as well. Despite significant recent progress, little is known at a molecular level regarding the mechanisms which are responsible for a switch from autoimmunity to tolerance in humans. This is particularly true with respect to sequential analysis of several molecular and immunologic markers during both the course and treatment of disease. Novel approaches are currently under way to fill the gaps. We will briefly detail here the experience gained to date, and identify some of the avenues which future research will explore.

Administration, Oral↗
PubMed1997

Genetic bias in immune responses to a cassette shared by different microorganisms in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease associated with HLA-DRbeta1 alleles which contain the QKRAA amino acid sequence in their third hypervariable region(s). The QKRAA sequence is also expressed by several human pathogens. We have shown previously that an Escherichia coli peptide encompassing QKRAA is a target of immune responses in RA patients. Here we address two questions: first, whether QKRAA may function as an "immunological cassette" with similar, RA-associated, immunogenic properties when expressed by other common human pathogens; and second, what is the influence of genetic background in the generation of these responses. We find that early RA patients have enhanced humoral and cellular immune responses to Epstein-Barr virus and Brucella ovis and Lactobacillus lactis antigens which contain the QKRAA sequence. These results suggest that the QKRAA sequence is an antigenic epitope on several different microbial proteins, and that RA patients recognize the immunological cassette on different backgrounds. ANOVA of immune responses to "shared epitope" antigens in monozygotic twin couples shows that, despite significantly elevated responses in affected individuals, a similarity between pairs is retained, thus suggesting a role played either by hereditary or shared environmental factors in the genesis or maintenance of these responses.

Antigen Presentation↗
PubMed1995

Positive selection in autoimmunity: abnormal immune responses to a bacterial dnaJ antigenic determinant in patients with early rheumatoid arthritis.

A novel 'multistep molecular mimicry' mechanism for induction of rheumatoid arthritis (RA) by bacterial antigens that activate T lymphocytes previously 'educated' by peptides derived from a class of human histocompatibility antigens is reported here. These antigens have the amino acid sequence QKRAA, which is also present on the Escherichia coli heat-shock protein dnaJ. Synovial fluid cells of early RA patients have strong immune responses to the bacterial antigen, but cells from normal subjects or controls with other autoimmune diseases do not. The activated T cells may cross-react with autologous dnaJ heat-shock proteins that are expressed at synovial sites of inflammation. Our findings may have direct relevance to new strategies for the immune therapy of RA.

Amino Acid Sequence↗
PubMed1995

Lack of temporal association of iridocyclitis with IgG reactivities to core histones and nucleosome subparticles in pauciarticular juvenile chronic arthritis.

This study aimed to measure IgG reactivities to DNA-free nucleosome subparticles (H2AH2B, H3H4) and nucleosome subparticles (H2AH2B-DNA, H3H4-DNA) and to evaluate the temporal relation of these reactivities, as well as those to single core histones, with iridocyclitis (IC) in patients with antinuclear antibody positive (ANA+) pauciarticular juvenile chronic arthritis (JCA). Reactivities to nuclear substrates were determined by enzymatic immunoassays in 120 sera from 45 children with ANA+ pauciarticular JCA. Significantly elevated IgG levels to H3 and H4, to DNA-free nucleosome subparticles, and to the nucleosome subparticle H3H4-DNA were present in patients with ANA+ pauciarticular JCA; no evidence of recognition of conformational epitopes was found. In both horizontal and follow-up studies, no relation between the reactivities studied and the development, presence, or history of IC was found. Our results show the absence of a relation of antibodies to histone molecules or to nucleosome subparticles with IC in patients with ANA+ pauciarticular JCA.

Adolescent↗
PubMed1994

Hypocomplementemic urticarial vasculitis syndrome with severe systemic manifestations.

We describe two children with clinical and laboratory features of hypocomplementemic urticarial vasculitis syndrome. Both patients had severe, life-threatening manifestations: rapidly progressive glomerulonephritis (patient 1) and pulmonary hemorrhage (patient 2). We conclude that this syndrome may be a potentially severe multisystem disease.

Adolescent↗
PubMed1994

Immune responses to the Escherichia coli dnaJ heat shock protein in juvenile rheumatoid arthritis and their correlation with disease activity.

Patients with juvenile rheumatoid arthritis frequently have abnormal immune responses to the hsp65 class of bacterial heat shock proteins. However, lymphocytes from children with other inflammatory diseases may also recognize hsp65, and the role of these antigens in juvenile rheumatoid arthritis remains controversial. We have studied humoral and cellular immune responses to a distinct, recently described bacterial heat shock protein, designated dnaJ. The Escherichia coli dnaJ gene was cloned and expressed, and the purified recombinant protein was used as an antigen. Neither normal children nor children with various chronic inflammatory diseases had lymphocyte proliferative responses to recombinant dnaJ. However, lymphocytes from patients with polyarticular, pauciarticular, and systemic manifestations of juvenile rheumatoid arthritis responded strongly to the antigen. Cellular immune responses to dnaJ were higher in synovial fluid than in blood and higher in children with active disease than in children in remission. These data show that increased immune reactivity to dnaJ is characteristic of juvenile rheumatoid arthritis and that the magnitude of the immune response is linked to disease activity. The results suggest that an abnormal immune response to antigens on commensal gut bacteria may contribute to the generation of chronic inflammation in juvenile rheumatoid arthritis.

Adolescent↗
PubMed1994

Serum soluble interleukin 6 (IL-6) receptor and IL-6/soluble IL-6 receptor complex in systemic juvenile rheumatoid arthritis.

By using a sandwich ELISA, soluble human IL-6 receptor (sIL-6 R) levels were measured in the sera of 20 healthy children and of 25 patients with systemic juvenile rheumatoid arthritis (JRA). In patients with systemic JRA, serum sIL-6 R levels (114.6 +/- 37.7 ng/ml) were significantly lower (P < 0.01) than those of healthy children (161.2 +/- 45.5 ng/ml). Serum sIL-6 R levels were negatively correlated (r = -0.610, P < 0.001) with serum IL-6 levels measured with the B9 cells. The serum IL-6/sIL-6 R complex was detected using an ELISA based on a monoclonal antibody to IL-6 for capture and on a monoclonal antibody to human sIL-6 R for detection. Healthy controls had little, if any, detectable serum IL-6/sIL-6 R complex (OD 0.024 +/- 0.027), while the majority of patients with systemic JRA presented measurable serum IL-6/sIL-6 R complex (OD 0.492 +/- 0.546). IL-6 levels estimated in the circulating IL-6/sIL-6 R complexes were in the range of nanograms per milliliter and approximately 20-fold higher than those measured by the B9 cells. Since serum C-reactive protein concentrations were much more correlated with serum levels of IL-6/sIL-6 R complexes (r = 0.713, r2 = 0.51, P < 0.0001) than with the serum IL-6 levels measured with the B9 cells (r = 0.435, r2 = 0.19, P = 0.05), the large quantities of serum IL-6 present in IL-6/sIL-6 R complexes appear to be biologically relevant in vivo, at least as far as the induction by IL-6 of acute phase protein production.

Adolescent↗
PubMed1993

Association of methotrexate treatment with a decrease of double negative (CD4-CD8-) and gamma/delta T cell levels in patients with juvenile rheumatoid arthritis.

OBJECTIVE: It has been suggested that double negative (CD4-CD8-) (DN) and gamma/delta T cells may be involved in some autoimmune diseases. We investigated peripheral blood DN and gamma/delta T cell levels in patients with active juvenile rheumatoid arthritis (JRA). METHODS: DN and gamma/delta T cell levels were measured in 42 patients with active JRA and in 10 healthy controls comparable for age by an immunofluorescence double staining procedure. RESULTS: All 3 JRA onset types had DN and gamma/delta T cell levels not significantly different from those of controls, although a wide scattering of data was present. No correlation was found between DN or gamma/delta T cell levels and erythrocyte sedimentation rate values or the number of active joints. When patients were divided according to treatment, we found that DN and gamma/delta T cell levels were significantly lower (p = 0.001, p = 0.02, respectively) in patients receiving methotrexate (MTX) than in patients not receiving MTX. The association of MTX treatment with a decrease in DN and gamma/delta T cell levels was also confirmed in a followup study of individual patients. Among patients not receiving MTX, patients with systemic JRA presented DN T cell levels significantly higher than those of controls. In 5 patients with pauciarticular JRA DN and gamma/delta T cell levels were higher in synovial fluid than in the peripheral blood. CONCLUSIONS: We found an increase in peripheral blood DN T cell levels in systemic JRA; treatment with MTX appears to be associated with a decrease in DN and gamma/delta T cell levels.

Adolescent↗