Antibody reactivity against thyroid peroxidase and myeloperoxidase in autoimmune thyroiditis and systemic vasculitis.

Potential cross-reactivity between thyroid peroxidase (TPO) and myeloperoxidase (MPO) molecules was evaluated by analysing the binding of 199 TPO antibody- and MPO antibody-positive sera to TPO and MPO molecules. Sera from six patients with autoimmune thyroiditis (AITD) and four patients with systemic vasculitis (SV) with different TPO-MPO antibody findings were then chosen for further analyses. All six patients with AITD had TPO antibodies in enzyme immunoassay (EIA) and four of them had simultaneously MPO antibodies in EIA.

Definition of three minimal T helper cell epitopes of rubella virus E1 glycoprotein.

To characterize T cell-recognized epitopes on rubella virus (RV) E1 glycoprotein, IL-2-dependent RV-specific T cell lines were established from 14 rubella-seropositive healthy donors. The responses of these lines were studied by using a panel of 94 partially overlapping synthetic peptides of 15 amino acids (aa) length covering the known nucleotide sequence of RVE1 glycoprotein. Two to seven peptide-defined epitopes were recognized by the T cell lines, but a large interindividual variation was found.

Antibody response to B cell epitopes of Chlamydia trachomatis 60-kDa heat-shock protein and corresponding mycobacterial and human peptides in infants with chlamydial pneumonitis.

To study antibody response to the hypersensitivity protein B of Chlamydia trachomatis, also known as the 60-kDa heat-shock protein (hsp60), epitope scanning was done over the entire protein. Human sera with antibodies to C. trachomatis identified 5 major antigenic regions (peptides 2, 5, 9, 17, and 21) and several minor regions (peptides 34-37, 39, 50, and 59-62).

Antibody reactivity to an Epstein-Barr virus BERF4-encoded epitope occurring also in Asp-57 region of HLA-DQ8 beta chain. Childhood Diabetes in Finland Study Group.

A five amino acids-long sequence (GPPAA) in the region of the 57th amino acid of HLA-DQ8 beta chain, which seems to be important in defining the risk for type 1 diabetes, occurs also in the BERF4-encoded EBNA3C protein of Epstein-Barr virus (EBV) in six successive repeats. The antigenicity of this region was analysed using synthetic peptides containing different modifications of the GPPAA sequence. Two of the seven individuals who had acute EBV infection produced antibodies against an EBV-derived peptide (GPPAAGPPAAGPPAA) paralleling the EBNA2 antibodies.

Antibodies to E1b protein-derived peptides of enteric adenovirus type 40 are associated with celiac disease and dermatitis herpetiformis.

Sera from 41 children with untreated celiac disease (CD), and 16 children with dermatitis herpetiformis (DH), and 57 matched controls were studied for serum antibodies to synthetic peptides derived from an early E1b protein of adenovirus type 12 and type 40 (Ad12, Ad40) and A-gliadin. In addition to peptides which share homology with A-gliadin, "nonhomologous" peptides derived from Ad12 and Ad40 E1b proteins were used as antigens in ELISA. Patients with CD and DH had significantly higher IgG antibody levels than those of controls to the nonhomologous Ad40 E1b peptide.

Evaluation of serum antibody response to a newly identified B-cell epitope in the minor nucleocapsid protein L2 of human papillomavirus type 16.

The aim of this work was to identify B-cell epitopes in the minor nucleocapsid (L2) protein of human papillomavirus (HPV) type 16 and characterization of allied antibody response. Serum samples of 513 individuals (323 women with various degrees of cervical atypia, 150 men and 40 small children) were available for the study. Synthetic peptides overlapping the L2 protein of HPV 16 twice were applied in ELISA for epitope scanning and antibody determination.

Defective HLA class II expression in monocytes of type 1 diabetic patients. The Childhood Diabetes in Finland Study Group.

Activation of T-helper cells is modulated by the intensity of HLA class II expression on antigen-presenting cells. We evaluated whether any abnormalities could be found in the expression of HLA-DR and -DQ molecules on monocytes in type 1 diabetic subjects. DR and DQ molecules were induced by human recombinant interferon-gamma on cultured peripheral blood monocytes obtained from children with type 1 diabetes (N = 28), their siblings (N = 18) and unrelated healthy controls (N = 21).

Common peptide epitope in mumps virus nucleocapsid protein and MHC class II-associated invariant chain.

The present study describes a 7 amino acid-long sequence (YQQQGRL) which is identical in HLA-associated invariant chain and mumps virus nucleocapsid protein and is additionally followed by one conservative amino acid pair. As such a long amino acid homology is extremely rare in two evolutionarily unrelated proteins the possibility that it could induce immunological cross-reactivity was evaluated. Several antigenicity indices suggested high antigen potential within this region.

Cross-reactivity between antibodies to thyroid microsomal antigens and myeloperoxidase.

Antibodies against thyroid microsomal antigen (thyroid peroxidase, TMA/TPO) and myeloperoxidase (MPO) were measured from 115 patients with vasculitic disorders and 144 patients with suspected thyroid disorders. Nineteen patients, three with vasculitis and 16 with thyroid disorders, were shown to have both TPO and MPO antibodies, suggesting cross-reactivity of these antibodies. Their cross-reactivity was further strengthened by studying the capacity of antibodies to tolerate dilution in enzyme immunoassay and reactivity with synthetic TPO/MPO peptides.

Determination of antibodies to non-structural and structural adenovirus antigens by ELISA.

We evaluated possibilities to analyze serum antibodies to non-structural (peptides derived from adenovirus E1b protein) and structural (hexon) adenovirus antigens by ELISA. Synthetic dodecapeptides covering a putative A-gliadin cross-reactive antigenic determinant of the E1b protein were used. The aminoterminus of the peptides appeared to be important for antibody binding but the exact sequence of a possible common B-cell epitope within the peptides remained open.

Mumps virus infects beta cells in human fetal islet cell cultures upregulating the expression of HLA class I molecules.

The ability of mumps virus to infect pancreatic Beta cells and cause alterations in their HLA expression was evaluated in cultured human fetal islet cell clusters. Mumps virus could be isolated during the whole culture period (6-8 days) and 60% of cells, including Beta cells, contained viral nucleocapsid protein at the end of the culturing. A minor decrease in insulin secretion was observed in some of the infected cultures.

Demonstration of evolutionary differences between conserved antigenic epitopes in the minor nucleocapsid protein of human papillomavirus types 6b, 16 and 18.

We studied human papillomavirus (HPV) minor nucleocapsid protein (L2) by epitope scanning. Conserved antigenic epitopes identified by rabbit antiserum to bovine papillomavirus (BPV) were revealed in HPV-6b (amino acids, aa, 196-205); HPV-16 (aa:s 376-85) and HPV-18 (aa:s 221-230). L2 proteins.