Calcium is involved in most cellular processes through calcium-binding proteins, belonging to the EF-hand superfamily. Recently new members of this family were found in the retina of vertebrates. Functions of these proteins and their relations to some neurological diseases are reviewed. Other EF-hand proteins found in the retina are also described.
Fimbriae play important role as pathogenic factors in many bacteria by their adhesive properties. Adhesin is located at the tip fimbriae but also in other parts of fimbriae. Recent findings on structure of fimbriae genes and their expression for the biosynthesis and formulation of complete fimbriae have been described. Special attention was focused on the participation of fimbriae in the mechanism of pathogenesis and their specificity towards tissue receptors. Most recent studies have been performed on E. coli and Klebsiella and those data predominate in this work. Fimbriae can be used for the construction of vaccine as a proteinous carrier for haptenic carbohydrate epitopes. In conjugates fimbriae express distinct immunogenic, adjuvant and protective properties.
Molecular mimicry is one of the most important pathogenic factor of microorganism and is defined as a structural similarity of microbial molecules to host tissue contributing to the pathogenicity. Mimicry can be observed at the molecular, serological and functional level. In the review the infectious diseases have been discussed where the mimicry phenomenon may occurr, and also autoimmune disease where due to the molecular mimicry bacterial structures are potent to induce adverse immune reactions. The cross-reacting molecules mimicking the host structures comprise colominic acid, sialic acid containing capsular polysaccharides of Streptococcus group B, phosphocholine containing antigen, lipopolysaccharides of Campylobacter jejuni contributing in induction of Guillain-Barre syndrome or Lewis antigen containing lipopolysaccharides of Helicobacter pylori inducing gut carcinoma. Knowledge on the phenomenon of molecular mimicry is important when new conjugate vaccine has to be constructed, because great care should be paid not to induce autoantibodies with synthetic immunogen. Investigation of microbial factors reveal that many autoimmune diseases are of infection etiology.
Introduction: Cancer-associated retinopathy (CAR) is a paraneoplastic neurological syndrome resulting in progressive loss of vision and clinical signs of retinal degeneration. It is associated with various types of cancer and is also considered to be an autoimmune disorder that involves cross-reaction between autoantibodies and retinal proteins. The aim of this study was to establish whether immunoreactivity to retinal antigens (RAs) observed in patients with breast cancer is accompanied by any visual impairments. Materials and Methods: Sera of 295 patients with diagnosed breast cancer were screened for the presence of anti-RAs antibodies using immunoblotting. Cellular immunoreactivity to RAs present in retinal extracts and to purified recoverin and arrestin was determined by means of a lymphocyte proliferation assay. Six patients with high-titer antibodies to RAs then underwent ophthalmic and neurological examinations. Results: Four serum samples contained high-titer antibodies to a 46-kDa protein, most probably retinal ?-enolase, three had antibodies to a 48-kDa protein identified as retinal arrestin, while 56-, 43-, 41-, and 34-kDa antigens were recognized only by one serum sample each. Moreover, weak cellular response to all the RAs tested was observed in one patient and another patient responded only to retinal extract. Two of the examined patients displayed symptoms of CAR. Conclusions: Immunoreactivity to RAs in patients with breast cancer may also be present in cases without clinical signs of CAR.
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