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EN
Tuberculosis (TB) remains a global health problem. There is an intense effort to identify correlates of protective immunity and to design new TB vaccines. CD8 T cells are thought to play a significant role in controlling Mycobacterium tuberculosis infection. Relatively little has been published about the antigens and epitopes targeted by mycobacteria-specific CD8 T cells. Here we present an update of our 1999 overview of human CD8 T cell epitopes in mycobacterial antigens and discuss related issues relevant to TB diagnosis and vaccine development.
EN
Advanced glycation end-products play an important role in diseases related to diabetes and aging processes. Model compounds are synthesized in order to prepare the diagnostic and experimental tools for studying the mechanisms of pathogenesis. The objective of the present study was to accelerate glycation and upgrade its efficiency under high-pressure conditions.Aqueous solutions of proteins were kept with carbohydrates under a pressure of up to 850 MPa for several hours. Then the high-pressure glycation (HPG) products were fractionated on a Sephadex G-200 column and characterized with SDS-PAGE and MALDI-TOF mass spectrometry. The low-molecular-mass fraction of glycated proteins was separated from the two fractions containing high- and intermediate-molecular-mass cross-linked products of glycation. The products were then compared with those obtained with the high-temperature glycation (HTG) procedure carried out in dry conditions with a lyophilized mixture of substrates. The fractionated products were used to prepare rabbit sera. The immunoblotting experiments showed that the epitopes on the cross-linked glycation products formed in solution under high pressure differed from those originating in dry conditions at high temperature. Sera against the HPG products were specific to homologous material and did not interact with the fractions obtained by HTG. The antibodies against HTG products recognized HTG but not HPG products.
EN
Gram-negative bacteria of genus Proteus are common human intestinal and urinary tract pathogens. In the genus Proteus there are four clinically important named species: P. mirabilis, P. vulgaris, P. penneri, and P. hauseri, and three unnamed Proteus genomospecies: 4, 5, and 6. The clinical significance of P. penneri, described in 1982 as a new species, is poorly documented. The aim of this work is serological characterization and classification of a ceftriaxone-susceptible P. penneri S29 strain isolated from a 34-year-old patient with postneurosurgical meningitis. In this characterization we will also include a ceftriaxon-resistant strain, P. penneri R15, isolated from the same patient after 12 days' treatment with ceftriaxon and other antibiotics. Rabbit polyclonal O-antisera were obtained against these two strains and purified lipopolysaccharides (LPS) were extracted from the bacterial mass of the P. penneri S29 and R15 strains. In the serological investigations the following tests were used: enzyme immunosorbent assay (EIA), passive immunohemolysis (PIH), inhibition of these tests, absorption of rabbit O-antisera with the respective LPS, and repeated PIH, SDS/PAGE, and Western blot techniques. The serological studies of the LPS extracted from both P. penneri strains showed the identity of both preparations of O-polysaccharides from LPS.. In P. penneri S29 O-antiserum, four different types of antibodies were described and characterized. Both investigated P. penneri S29 and R15 strains were classified to the Proteus O31ab serogroup.
EN
Introduction: Proteus penneri lipopolysaccharide (LPS) core regions are characterized by a greater structural variability than that observed in other Enterobacteriaceae. This fact and the small amount of published data concerning the serological activity of this part of P. penneri LPS prompted an examination of which fragment might determine cross-reactions with antibodies. To date, such epitopes have been found in the LPS core regions of P. mirabilis and P. vulgaris strains. Materials and Methods: Proteus sp. LPSs were tested with unabsorbed rabbit antisera by enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot, and once again by ELISA or passive immunohemolysis after the absorption of these antisera with selected LPSs. Results: The serological studies of P. penneri 8 LPS demonstrated antibodies in the tested antisera recognizing a common epitope located in the core regions of six of the LPSs, i.e. P. penneri 8, 34, 133, 7, 14, and 15. Additionally, another type of antibody directed against some fragment of P. penneri 13 and the core regions of other LPSs investigated was observed in one antiserum. Conclusions: A distal, trisaccharide fragment of the P. penneri 8 LPS core region is suggested to determine the cross-reactions of the tested antisera with the six P. penneri LPSs.
EN
Introduction: Proteus rods are currently subdivided into five named species, i.e. Proteus mirabilis, P. vulgaris, P. penneri, P. hauseri, and P. myxofaciens, and three unnamed Proteus genomospecies 4 to 6. Based on the serospecificity of the lipopolysaccharide (LPS; O-antigen), strains of P. mirabilis and P. vulgaris were divided into 49 O-serogroups and 11 additional O-serogroups were proposed later. About 15 further O-serogroups have been proposed for the third medically important species, P. penneri. Here the serological classification of P. vulgaris strain TG 251, which does not belong to these serogroups, is reported. Serological investigations also allowed characterization of the epitope specificity of its LPS. Materials and Methods: Purified LPSs from five Proteus strains were used as antigens in enzyme immunosorbent assay (EIA), SDS/PAGE, and Western blot and alkali-treated LPSs in the passive immunohemolysis (PIH) test, inhibition of PIH and EIA, and absorption of the rabbit polyclonal O-antisera with the respective LPS. Results: The serological studies of P. vulgaris TG 251 LPS indicated the identity of its O-polysaccharide with that of P. penneri O65. The antibody specificities of P. vulgaris TG 251 and P. penneri O65 O-antisera, were described. Conclusions: P. vulgaris TG 251 was classified to the Proteus O65 serogroup. Two disaccharide-associated epitopes present in P. vulgaris TG 251 and P. penneri O65 LPSs are suggested to be responsible for cross-reactions with three heterologous Proteus strains.
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