Isolation and study of active peptides in Salmonella H antigens

The monomer forms of Salmonella H-antigens a, b, d, i, 1, 2 have both specific antigenic determinants, characteristic of each H-antigen, and common determinants. The presence of two types of determinant groups leads to the appearance of cross reactions in the enzyme immunoassay. In this work the method for the isolation of peptides carrying only specific antigenic determinants is proposed.     

The common antigenic determinants of the H antigens of salmonellae]

Salmonella H-antigens have common and specific antigenic determinants. Studies on the determination of common antigenic determinants of H-antigens (a; b; d; i; 1,2 and nt) has been carried out. The order of the distribution of H-antigens according to the decrease of these common antigenic determinants in size is presented: d greater than a greater than 1,2 greater than b greater than nt. These data broaden our knowledge of the structure of H-antigens; they are also necessary for obtaining specific antibodies and conjugate preparations used in the enzyme immunoassay.     

Monosaccharide composition of the lipopolysaccharides of bacteria of the genus Citrobacter

The authors studied antigens obtained by Grasset's method from 13 strains of Citrobacter of the International collection. The strains possessed O- and H-antigens whose behaviur in the electric field differed. All the strains under study were divided into two groups (by the number of serologically-active components of their O-antigens); representatives of the second group had no cathode O-antigen component. Chemical composition of specific lipopolysaccharides (LPS) obtained by Westphal's method was determined. Fourteen different sugars were revealed. The strains under study were referred to the known chemotypes. Strain 16/52 (8a, 8c) was for the first time studied in respect to the monosaccharide composition of specific LPS, and was referred to chemotype designated as CC-L.     

The development of methods for obtaining monospecific ingredients for immunoenzyme analysis

The methods of the modification of Salmonella O- and H-antigens and the preparation of biologically active sorbents on their basis have been developed. The use of these sorbents has permitted the isolation of affinity antibodies with strictly defined specific activity. The work shows the possibility of the successful use of carriers obtained on the basis of porous glass, chemically modified by acrylic copolymers containing activated carboxylic groups, and intended for the immobilization of antigens of both protein and carbohydrate nature.     

Reactogenicity and immunological effectiveness study of a complex paratyphoid B antigen]

Reactogenic property and immunological efficacy of the paratyphoid preparation containing a complex of O-, K- and H-antigens obtained by single-stage antigens extraction were studied in a limited group of volunteers (22 persons). The antigen gave no untoward reactions and proved to be safe when given orally in doses of 25 to 150 mg. Paratyphoid B antigen was characterized by a marked immunization activity and stimulated formation of specific paratyphoid O-, K- and H-agglutinins and antibodies of the IgA,- IgG,- and IgM-classes.     

Molecular relationships of the human B cell alloantigens, MT2, MB3, MT4, and DR5

The human class II, HLA-linked, B cell alloantigens include the HLA-DR, MB, MT, and Te determinants. Interest in the molecular relationships of these antigens has recently intensified because of their homology to the murine Ia antigens and their possible importance in disease predisposition and transplantation. We have used alloantisera with carefully defined immunochemical as well as serologic specificity, and two immunochemical techniques, sequential immunoprecipitation with analysis by SDS-PAGE and two-dimensional gel electrophoresis, to explore the molecular relationships of the MT2, MB3, MT4, and HLA-DR5 antigenic determinants. The data presented here indicate that 1) all class II molecules that bear the DR5 antigenic determinant also bear the MT2 antigenic determinant; (2) the homozygous DR5 cell line, Swei, expresses at least two structurally distinct class II molecules, both of which bear MT2: one bears the MT2, MB3, and MT4 antigenic determinants, and the second bears the MT2, but not the MB3 or MT4 antigenic determinant; and (3) the DR5 determinant is located on at least one and possibly both of these distinct class II molecules.     

Immunoelectrophoretic analysis of the antigenic composition of Salmonella typhi in the process of L transformation and reversion

In the study of the antigenic composition of S. typhi L-forms and their revertants were determined. The stable L-forms were characterized by profound disturbances in the synthesis of Vi- and H-antigens. After reversion to bacterial forms all the revertants under study showed the complete restoration of their bacterial antigenic structure.     

Antigenic differences between tumor-associated fetal antigens and rat histocompatibility antigens

Certain molecular properties of purified tumor-associated fetal antigens (TAFA) were analyzed by sequential immune precipitation (SIP), isoelectric focusing, and high-pressure liquid chromatography (HPLC). The antigenic relatedness of rat histocompatibility antigens and the various TAFA were determined by SIP. SIP of chloramine-T-labeled purified TAFA or lactoperoxidase-iodinated tumor cell membranes, in the presence of rat alloantisera and monospecific rabbit anti-TAFA sera demonstrated no antigenic cross-reactivities or similarities between H-antigens and TAFA. TAFA were also compared with histocompatibility antigens for isoelectric point optima and molecular weight. Rat H-antigens had isoelectric points in the 7.0–8.5 pH range, whereas all TAFA focused at pH 5.0–6.5 or above pH 8.0. Molecular weights were determined by HPLC. TAFA-I and TAFA-III had molecular weights of 16,000–17,500 daltons, whereas TAFA-II had a molecular weight of 12,000. The antigens were not coprecipitated by the rat alloantisera. Each TAFA was also isolated (via immune precipitation) from NP-40-solubilized tumor cell membranes. These TAFA were identical to the chloramine-T-labeled TAFA which had been previously extracted and purified from rat fibrosarcomas and osteosarcomas. These studies demonstrated that although TAFA and H-antigens cocap on embryonic and transformed cell membranes, these determinants are different molecules; they are not covalently linked on cell membranes; and TAFA are not cleavage products of normal NBR H-antigens.     

Antigenic characteristics of standard strains of Providencia rettgeri (O- and H-antigens)

Additions and changes have been introduced into the existing antigenic diagnostic scheme of P. rettgeri on the basis of the study of the antigenic structure of standard strains from foreign collections: new, formerly unknown varieties of somatic and flagellar antigens (O35, O36, H27, H28) have been discovered, the complex of antigenic factors for H-antigens 7, 10, 23, 27 has been discovered. Strains 958 (36 : 28) and 979 (16 : 27a, 23b, 2a), previously classified with the genus Morganella, have been identified by O- and H-antigens.     

抗肿瘤免疫毒素稳定性的研究进展

免疫毒素 (immunotoxins)是由某些细菌和植物产生的毒素蛋白与抗体或生长因子等靶向分子连接而成 ,用于杀伤表面带有特定抗原或受体的细胞。在试验中 ,免疫毒素在肿瘤周围环境中的稳定性是影响其抗肿瘤效果的主要因素之一。本文主要对几种由不同形式的抗体Fv段构建的免疫毒素的稳定性进行了比较 ,并对定点突变和PEG化学修饰提高免疫毒素稳定性的方法做一简要介绍。     

Relationship between the secretor status and the expression of ABH blood group antigenic determinants in human intestinal brush-border membrane hydrolases

At least six hydrolases of the human intestinal brush-border membrane bear ABH blood group antigenic determinants related to the erythrocyte phenotype: the intestinal glycoproteins of blood group A and B subjects express A or B determinants, respectively, while blood group O subjects express the H determinant identified with Ulex europaeus lectin I. These expressions are under the control of the secretor gene: ABH antigens were not detected in the hydrolases of non-secretor subjects.     

Parathyphoid B-antigen containing a complex of protective surface antigens]

The authors obtained a complex antigen from paratyphoid B bacilli containing complete O-, K- and H-antigens. The preparation was nontoxic and was characterised by marked antigenic properties. In intravenous and oral administration it stimulated production of specific O-, K-, and H-antibodies in high titres. Complex paratyphoid B antigen possessed a marked protective activity and provided intense immunity in subcutaneous and oral administration to experimental animals.     

Relationship between the secretor status and the expression of ABH blood group antigenic determinants in human intestinal brush-border membrane hydrolases

At least six hydrolases of the human intestinal brush-border membrane bear ABH blood group antigenic determinants related to the erythrocyte phenotype: the intestinal glycoproteins of blood group A and B subjects express A or B determinants, respectively, while blood group O subjects express the H determinant identified with Ulex europaeus lectin I. These expressions are under the control of the secretor gene: ABH antigens were not detected in the hydrolases of non-secretor subjects.     

Complex fucolipids of hog gastric mucosa. Structure of the ceramide eikosahexoside

The structure of a complex fucolipid from hog gastric mucosa containing twenty sugar residues and exhibiting blood-group (A + H) activity has been investigated. Based on the results of immunological assays, partial acid hydrolysis, sequential degradation with specific exoglycosidases, oxidation with periodate and chromium trioxide, and permethylation analysis, we suggest that the carbohydrate chain of this fucolipid contains four termini. One of the termini bears beta Gal1 leads to 4 beta GlcNAc disaccharide, two bear blood-group A determinant and one bears H determinant. Two of the branches, terminated by beta Gal1 leads to 4 beta GlcNAc and blood-group A determinant, and two terminated by blood-group A and H determinants, are linked through beta Gal1 leads to 4 beta GlcNAc1 leads to 3/6 and beta Gal1 leads to 4 beta GlcNAc1 leads to 4 beta GlcNAc1 leads to 3/6 to the galactose residue adjacent to glucosylceramide core.     

Differential ability of tumor-unique and cross-reactive antigen(s) on two murine hepatoma cell lines to induce Lyt-1+2- T cells responsible for in vivo protective immunity

The role of the tumor-unique determinant(s) on two syngeneic murine hepatoma cells in inducing in vivo protective immunity was investigated in comparison with that of the tumor-cross-reactive determinant(s). Induction of vaccinia-reactive helper T cells in C3H/He mice by intraperitoneal (i.p.) inoculation of viable vaccinia virus and then immunization with vaccinia-infected syngeneic MH134 or MH129 tumor cells resulted in the production of potent anti-MH134 or -MH129 antibody as well as the generation of in vivo protective immunity. Neither antibody reacted with other syngeneic plasmacytoma or fibrosarcoma cells, but both cross-reacted appreciably with the other hepatoma cells as well reacted strongly as with the tumor cells used for immunization. The absorptions of anti-MH134 and -MH129 antisera with the respective hepatoma cells abolished their reactivities with both the corresponding hepatoma cells and the other hepatoma cells. In contrast, the absorption of these antisera with the other tumor cells resulted in loss of their cross-reactivities with the other hepatoma cells, but not loss of their specific reactivity to the respective hepatoma cells. Although in these hematoma systems, the above-mentioned immunization protocol resulted in in vivo induction of protective immunity and generation of antibodies, in vivo immunity as observed by Winn assays was mediated by Lyt-1+2- T cells and was specific for each type of hepatoma cells. These results indicate that these two types of hepatoma cells bear two kinds of antigenic determinants, one kind unique to each hepatoma and the other kind cross-reactive with the other hepatoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Determination of Salmonella typhimurium antigens in the excreta of children with salmonellosis using the passive hemagglutination reaction

1,390 samples of different excreta obtained from salmonellosis patients have been tested for the presence of S. typhimurium O- and H-antigens. S. typhimurium antigens, detected with the use of antibody diagnostica, have been found to occur more frequently than S. typhimurium cells. Particulate O- and H-antigens capable of agglutinating antibody diagnostica are excreted differently with saliva and urine. Salmonella antigens are best detected in feces in the passive hemagglutination test with the use of antibody diagnostica, but not in the antibody neutralization test. The combination of the passive hemagglutination test, carried out with the use of antibody diagnostica, and bacteriological study considerably enhances the efficiency of diagnosing salmonellosis in children in comparison with bacteriological study alone.     

Monoclonal antibodies specific for type 3 and type 4 chain-based blood group determinants: Relationship to the A1 and A2 subgroups

Two monoclonal antibodies, specific for A type 3 and A type 4 blood group determinants, are described. These antibodies recognized A1 but not A2 erythrocytes. A third monoclonal antibody showing specificity for A type 3 and A type 4, and also for H type 3 and H type 4, did not discriminate between A1 and A2 erythrocytes. On red cells these three antibodies recognized glycosphingolipids and binding to glycoproteins could not be demonstrated. On paraffin-embedded tissue sections the three antibodies labelled a supranuclear area, characteristic of the Golgi apparatus, of all cells producing A antigens. This labelling occurred irrespective of the A1, A2 status.The results suggest that glycolipids of erythrocytes and possibly of other cell types bear the A type 3/4 determinant specific for the A1 subgroup and that A type 3/4 determinants of glycoproteins might be present in both A1 and A2 subgroups on short oligosaccharide chains which are only detectable at the level of the Golgi apparatus.     

The influence of the exocyclic amino group characteristic of GC base pairs on molecular recognition of specific nucleotide sequences in DNA by Berenil and DAPI

The expedient of preparing homologous DNA samples substituted with inosine for guanosine residues, 2,6-diaminopurine (DAP) for adenine residues, or both, has been used to investigate the role of the purine 2-amino group in determining the preferred binding sites for the drugs berenil [1,3-bis(4-phenylamidinium) triazene] and DAPI (4′,6-diamidino-2-phenyl indole) on DNA. The selectivity of these two minor groove binders for AT-rich sequences is seen to be radically altered in the substituted DNA molecules. Neither berenil nor DAPI bind to DAP-substituted DNA where all purine residues bear a 2-amino group. By contrast, they bind to AT-rich, IC-rich and even mixed sequences of the inosine DNA where all purine residues lack the 2-amino group. With the inosine and DAP double substituted DNA, both berenil and DAPI bind preferentially to IC-rich clusters instead of their canonical tracts endowed with an extra 2-amino group through substitution with DAP. These results establish that the location of the purine 2-amino group represents a critical determinant for recognition of DNA nucleotide sequences by the two drugs. © 1997 John Wiley & Sons, Ltd.     

Further characterization of the suppressor cells, activated by goat anti-Th-B antibody reagent and responsible for enhanced growth of sarcoma 180 in AKR mice.

In our previous study, thymus cells were shown to be responsible for enhancing the growth of the allogeneic sarcoma 180 (S180) in AKR mice that had been injected with goat anti-Th-B antibody reagent (antiserum raised in goats against Balb/c myeloma MOPC 104E cells and purified). We suggested that the cells producing enhancement are suppressor T cells. We now show that the cells responsible for tumor enhancement are indeed T cells, since they carry the Thy-1 antigen on their surface. Treatment of the cells in vitro with anti-Thy-1 plus complement completely eliminates their ability to enhance tumor growth. The thymocytes responsible for tumor enhancement do not carry the Th-B determinant. Treating thymocytes in vitro with goat anti-Th-B antibody reagent plus complement does not abrogate their tumor-enhancing activity. This suggests that the suppressor T cells involved in tumor enhancement are generated by the interaction of anti-Th-B antibodies with precursor suppressor cells which do carry Th-B. Once generated, the active suppressor cells lose the Th-B antigen. This suggestion is supported by our finding that the thymic precursors of Con A-inducible suppressor cells bear Th-B, since they are killed by anti-Th-B plus complement, whereas active suppressor cells induced by Con A do not carry Th-B, since they are not killed by anti-Th-B plus complement. Neither splenic precursors of Con A-inducible suppressor cells nor the active suppressor cells thus induced carry Th-B since neither is killed by anti-Th-B plus complement. We have also found that there are apparently nonthymic suppressor cell precursors which can also be activated by anti-Th-B, since spleen cells from thymectomized mice bearing S180 and treated with anti-Th-B can transfer the tumor-enhancing effect. We conclude that precursors of suppressor cells carry the Th-B determinant. These precursors differentiate to active suppressor cells when stimulated by anti-Th-B antibodies. This process can take place either outside the thymus or in the thymus. Once differentiated, the mature suppressor cells no longer bear the Th-B marker and migrate from their sites of induction. Such cells can suppress immune mechanisms responsible for allogeneic tumor graft rejection and thus cause tumor enhancement.     

Antigenic marker of human erythrokaryocytes similar to mouse erythroblastosis antigen]

Identical antigenic determinants are discovered on the surface of human erythrokaryocytes with antibodies against specific antigen of murine erythroblasts (Ag-Ed), previously revealed in study of Rauscher leukemia, in the immunofluorescent and cytotoxic tests. The antigen is present on the membranes of the majority of human embryonic liver and adult bone marrow nuclear erythroid cells, but is not found in fetal thymocytes, newborn kidney cells, adult human hepatic cells and in peripheral blood erythrocytes. Ag-Eb appears to possess an inter-species determinant, shared by mammalian nuclear erythroid cells, and may be used as their specific marker.