The study of the antigenic properties of cells of the HeLa strain using the agglutination reaction

SummaryRabbits immunized against human AHG fibrinogen-free preparations, were shown to produce anti-AHG antibodies. The inhibitory activity of these antibodies was tested by thromboplastin generation test, thrombelastography, and the specific anti-AHG antibodies neutralization test. The latter test permitted quantitative determination of antigenic form of factor VIII. The inhibitory activity of anti-FI-O-Ta serum resulted exclusively from the anti-AHG antibodies which in coagulation tests behaved like circulating anticoagulants directed against factor VIII.The anti-AHG antibodies were neutralizable by normal human serum or plasma even contained only trace of AHG activity after storage. There was no antigenic form of factor VIII in the severely affected patients with hemophilia A, von Willebrand’s disease nor in the normal plasma adsorbed on bentonite. The presented results suggest a molecular defect of factor VIII in patients with hemophilia A. The severe form of this disease depends, probably, on a major impairment of AHG biosynthesis, leading to changes in the antigenic properties of the molecule. The AHG from rabbit, porcine and bovine plasma respectively did not neutralize the anti-AHG antibodies formed in rabbits immunized against human factor VIII preparations.

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CHEMISTRY OF GONADOTROPHINS IN RELATION TO THEIR ANTIGENIC PROPERTIES

Acta Endocrinologica ◽

10.1530/acta.0.062s013 ◽

1969 ◽

Vol 62 (1_Suppl) ◽

pp. S13-S30 ◽

Cited By ~ 8

Author(s):

W. R. Butt

Keyword(s):

Biological Activity ◽

Guinea Pigs ◽

Complement Fixation ◽

Neuraminic Acid ◽

Fixation Technique ◽

Immunological Activity ◽

Antigenic Properties ◽

Specific Antisera ◽

Structural Differences

ABSTRACT Several chemical differences between FSH, LH and HCG have been reported: thus LH and HCG are richer in proline than FSH and FSH and HCG contain more N-acetyl neuraminic acid than LH. Sub-units of LH are formed by treatment with urea, guanidine or acid. HCG also may contain two sub-units. The sub-units from LH are biologically inert but retain their immunological activity: biological activity is restored when the sub-units are incubated together. There is much evidence from chemical and enzymic reactions that antigenic groups are distinct from those parts of the molecule essential for biological activity. N-acetyl neuraminic acid and probably other carbohydrates in FSH and HCG are not involved in immunological activity but are necessary for biological activity. Histidine, methionine and possibly cysteine appear to be essential for biological but not immunological activity of FSH, while tryptophan and possibly tyrosine are not essential for either. A few highly specific antisera to gonadotrophins have been prepared in rabbits and guinea pigs to crude antigens: there is no evidence that purified antigens are more likely to produce specific antisera. Differences in the immunological reactivities of urinary compared with pituitary gonadotrophins have been observed both by radioimmunoassay and by the complement fixation technique. The latter may be particularly useful for detecting structural differences in the hormones.

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Agglutination reaction procedures for normal and tumor tissue cells and for the cytotoxic reaction in vitro

Bulletin of Experimental Biology and Medicine ◽

10.1007/bf00782326 ◽

1964 ◽

Vol 57 (5) ◽

pp. 587-590 ◽

Cited By ~ 2

Author(s):

B. D. Brondz

Keyword(s):

Tumor Tissue ◽

Agglutination Reaction ◽

Cytotoxic Reaction ◽

Tissue Cells

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Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽

10.3390/v13071385 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1385

Author(s):

Giulia Pezzoni ◽

Lidia Stercoli ◽

Eleonora Pegoiani ◽

Emiliana Brocchi

Keyword(s):

Hepatitis E Virus ◽

Hepatitis E ◽

Recombinant Antigen ◽

Open Reading Frame ◽

Reading Frame ◽

E Coli ◽

Antigenic Characterization ◽

Antigenic Properties ◽

Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

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Brown Spiders’ Phospholipases-D with Potential Therapeutic Applications: Functional Assessment of Mutant Isoforms

Biomedicines ◽

10.3390/biomedicines9030320 ◽

2021 ◽

Vol 9 (3) ◽

pp. 320

Author(s):

Thaís Pereira da Silva ◽

Fernando Jacomini de Castro ◽

Larissa Vuitika ◽

Nayanne Louise Costacurta Polli ◽

Bruno César Antunes ◽

...

Keyword(s):

Structural Changes ◽

Capillary Permeability ◽

Structural Data ◽

Histopathological Analysis ◽

Amino Acid Residues ◽

Wild Type ◽

Antigenic Properties ◽

Harmful Effects

Phospholipases-D (PLDs) found in Loxosceles spiders’ venoms are responsible for the dermonecrosis triggered by envenomation. PLDs can also induce other local and systemic effects, such as massive inflammatory response, edema, and hemolysis. Recombinant PLDs reproduce all of the deleterious effects induced by Loxosceles whole venoms. Herein, wild type and mutant PLDs of two species involved in accidents—L. gaucho and L. laeta—were recombinantly expressed and characterized. The mutations are related to amino acid residues relevant for catalysis (H12-H47), magnesium ion coordination (E32-D34) and binding to phospholipid substrates (Y228 and Y228-Y229-W230). Circular dichroism and structural data demonstrated that the mutant isoforms did not undergo significant structural changes. Immunoassays showed that mutant PLDs exhibit conserved epitopes and kept their antigenic properties despite the mutations. Both in vitro (sphingomyelinase activity and hemolysis) and in vivo (capillary permeability, dermonecrotic activity, and histopathological analysis) assays showed that the PLDs with mutations H12-H47, E32-D34, and Y228-Y229-W230 displayed only residual activities. Results indicate that these mutant toxins are suitable for use as antigens to obtain neutralizing antisera with enhanced properties since they will be based on the most deleterious toxins in the venom and without causing severe harmful effects to the animals in which these sera are produced.

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Schistosoma mansoni: a comparative study of artificially transformed schistosomula and schistomula recoverd after cercarial penetration of isolated skin

Parasitology ◽

10.1017/s0031182000047545 ◽

1977 ◽

Vol 74 (1) ◽

pp. 73-86 ◽

Cited By ~ 81

Author(s):

Linda H. Brink ◽

Diane J. McLaren ◽

S. R. Smithers

Keyword(s):

Comparative Study ◽

Schistosoma Mansoni ◽

Amorphous Material ◽

Surface Membrane ◽

Antigenic Determinants ◽

Agglutination Reaction ◽

Rat Serum ◽

Mechanical Separation ◽

B Blood Group

A comparison was made of the ultrastructure, development and antigenic nature of the surfaces and of the viability of three types of schistosomula of Schistosoma mansoni: schistosomula formed afrer cercariae had penetrated isolated skin (SS), schistosomula produced after mechanical separation of cercarial tails from bodies (MS), and schistosomula transformed from cercariae after incubation in fresh rat serum (RS).Within 2 h of transformation, the surface membrane of all three types of schistosomula had changed from trilaminate to heptalaminate structures and SS and MS had lost their cercarial glycocalyx. Initially a dense amorphous material was demonstrated on the surfaces of RS, which was thought to be the result of an interaction between a factor in rat serum and the glycocalyx: this material was greatly reduced within 2 h of transformation. The pre-acetabular glands of SS were emptied while those of MS and RS retained their contents. Immunofluorescent studies showed that all schistosomula bound serum from mice immune to S. mansoni, but the binding was stronger with MS and RS. The mixed agglutination reaction demonstrated the presence of human A and B blood group-like antigenic determinants on approximately 30% of 3 h old SS; these determinants were not detected on MS or RS. In vitro, the development of MS and RS was similar to SS; the first schistosomula reached the ‘gut-closed’ stage by day 10; 50–70% of SS reached this stage by day 12, in contrast to only 25–50% of MS and RS. Between 28 and 45% of all schistosomula developed to maturity when injected intravenously into mice.It was concluded that the two types of artificially prepared schistosomula fultil the main criteria of transformation from cercaria to schistosomulum. Further, it is suggested that MS are the most appropriate source of material for immunochemical and physiological studies.

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In-silico design of envelope based multi-epitope vaccine candidate against Kyasanur forest disease virus

Scientific Reports ◽

10.1038/s41598-021-94488-8 ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Sathishkumar Arumugam ◽

Prasad Varamballi

Keyword(s):

Disease Virus ◽

In Silico ◽

Hemorrhagic Fever ◽

Epitope Vaccine ◽

Epitope Region ◽

Vaccine Candidates ◽

Forest Disease ◽

In Silico Design ◽

Antigenic Properties ◽

Kyasanur Forest Disease

AbstractKyasanur forest disease virus (KFDV) causing tick-borne hemorrhagic fever which was earlier endemic to western Ghats, southern India, it is now encroaching into new geographic regions, but there is no approved medicine or effective vaccine against this deadly disease. In this study, we did in-silico design of multi-epitope subunit vaccine for KFDV. B-cell and T-cell epitopes were predicted from conserved regions of KFDV envelope protein and two vaccine candidates (VC1 and VC2) were constructed, those were found to be non-allergic and possess good antigenic properties, also gives cross-protection against Alkhurma hemorrhagic fever virus. The 3D structures of vaccine candidates were built and validated. Docking analysis of vaccine candidates with toll-like receptor-2 (TLR-2) by Cluspro and PatchDock revealed strong affinity between VC1 and TLR2. Ligplot tool was identified the intermolecular hydrogen bonds between vaccine candidates and TLR-2, iMOD server confirmed the stability of the docking complexes. JCAT sever ensured cloning efficiency of both vaccine constructs and in-silico cloning into pET30a (+) vector by SnapGene showed successful translation of epitope region. IMMSIM server was identified increased immunological responses. Finally, multi-epitope vaccine candidates were designed and validated their efficiency, it may pave the way for up-coming vaccine and diagnostic kit development.

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