Redox processes in allergic reactions of the delayed type to microbial antigens]

The influence of common allergic response of delayed type to brucellosis antigen on the processes of glycolysis and dehydrogenase activity of Krebs' cycle in guinea pigs' blood and organs was studied. Along with inhibitory activity of four dehydrogenases investigated there was a depression of the glucolysis processes connected with reduction of the lactate, pyruvate content, and with depression of the LDH activity. An increase of the anaerobic fractions and lowering of aerobic fractions content and of the spectrum excess was seen in the isoenzyme LDH spectrum.     

Specific experimental therapy in sensitization to group A streptococci]

A model of delayed hypersensitivity to Streptococcus hemolyticus, group A, were obtained in guinea pigs and rabbits. Studies of spontaneous changes of the immuno-allergic reactivity revealed that after a month of sensitization there developed delayed hypersensitivity only; according to the results of late skin tests it lasted not less than 6 months (the duration of investigation). The delayed hypersensitivity component began to manifest itself in 2 1/2 to 3 months and increased later on. Specific hyposensitization was performed with streptococcus allergens differing by physico-chemical conditions, i.e. the corpuscula allergen, the one that was lysed by ultrasonic waves, and Ando-Verzhikovsky's allergen. The latter had the most intensive hyposensitizing features. Specific hyposensitization was more demonstrative after the intracutaneous long-term course injections of threshold doses. Administration of subthreshold doses, as well as subcutaneous or intravenous injections of the allergen, was ineffective.     

The type antigen III of group F streptococci separation of group and type antigens and partial characterization of type III antigen

Polysaccharides extracted from Z₃III streptococci either with formamide or with dilute hydrochloric acid or isolated from the growth medium could be fractionated in type III- and group Z₃ antigens by alcohol precipitation. No good separation could be obtained from TCA extracts. When the same extractions and fractionations were applied to streptococci carrying type III antigen, but different group antigens, good separations were again obtained of all formamide extracts, but not of all hydrochloric acid extracts. The group antigens showed a rhamnose content of at least 50% and contained hexosamines. Type III antigens contained mainly rhamnose, glucose and galactose in relative amounts of approximately 1:2:3. Analysis of the methylated type III antigen suggests it to be a polysaccharide with a linear structure. Type III antigen isolated from the medium was characterized not only by a different sugar ratio, but also by its fucose content of 20%. In some cases the purified polysaccharides contained considerable amounts of glycogen-like material. Partial acid hydrolysis of the type III antigen extracted with formamide yielded a great number of oligosaccharides. Analyses, inhibition reactions and methylation studies gave indications that the most probable structure of a determinant group of type III antigen is β-glucosyl-(1-6)-galactosyl-(1-6)-galactosyl-(1-3)-rhamnose. The possibility of the existence of a second determinant group is discussed.     

Heart cross-reactive antigens of mutans streptococci share epitopes with group A streptococci and myosin

Monoclonal antibodies (mAb) generated by immunization of mice with membranes of Streptococcus pyogenes Manfredo (M type 5) were tested for their reactivity with sodium dodecyl sulfate extracts of Streptococcus mutans GS5, Streptococcus rattus BHT (formerly S. mutans, serotype b), and S. mutans Ingbritt 175 in the Western blot. The reaction of the sodium dodecyl sulfate-extracted proteins of whole S. mutans, serotype b), and S. rattus with the mAb revealed that the shared cross-reactive antigens were near m.w. 62,000 to 67,000. Several higher m.w. proteins in S. mutans Ingbritt 175 reacted with the mAb but were not observed in the other two strains of streptococci. Cytoplasmic membranes of S. rattus BHT reacted with these mAb in the enzyme-linked immunosorbent assay and Western blot. The most reactive BHT membrane component detected by these mAb was a 62-kDa polypeptide that was similar in m.w. to the membrane component recognized by these antibodies in purified S. pyogenes membranes. The reactivity of the mAb with BHT membranes in the enzyme-linked immunosorbent assay was absorbed by rabbit skeletal muscle myosin. The patterns of reactivity observed in the BHT membrane immunoblots in this study closely resemble those previously obtained using polyclonal rabbit anti-human heart sera.     

Immunodiffusion methods of studying the F-fraction antigens obtained from group A streptococci]

F fractions, obtained by the extraction of cultures of group A streptococci with distilled water at different pH, were studied by immunodifusion methods and subjected to chemical analysis. F fractions were shown to contain polyglcerophosphate, antigen E4 and in some cases group polysaccharide. Besides, F fractions were found to contain an antigen insensitive to trypsin and identical to one of the antigens of the thermostable fraction, as well as an antigen sensitive to the action of proteolytic enzymes and common to various types of group A streptococci. The antigen sensitive to the action of proteolytic enzymes were identical to one of the antigens showing no type specificity and contained in HC1 extracts prepared from group A streptococci. In grouping and typing group A streptococci the present of some F fraction antigens unrelated either to polysaccharide or to M substance should be taken into consideration. The antigens of F fraction have no protective properties.