| 1. |
- Muthukkaruppan, V. R., et al.
(author)
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Monoclonal antibodies against Salmonella porins : generation and characterization
- 1992
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In: Immunology Letters. - Amsterdam : Elsevier. - 0165-2478 .- 1879-0542. ; 33:2, s. 201-206
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Journal article (peer-reviewed)abstract
- Monoclonal antibodies (mAbs) were generated against porins, one of the major outer membrane proteins of Salmonella typhi. Six clones, designated MP1, MP2, MP3 (IgG2ak), MPN4, MPN6 (IgG1k) and MPN5 (IgG2bk) were characterized by enzyme immunoassay (ELISA) for their reactivity to porins from S. typhi, Salmonella paratyphi A, S. paratyphi B, S. paratyphi C, Salmonella choleraesuis, Salmonella enteritidis, Salmonella krefeld, Salmonella panama, Salmonella typhimurium, Escherichia coli B, Shigella flexneri 1b and Pseudomonas aeruginosa. All the clones positive for S. typhi porins showed varying reactivity towards several Salmonella species. However, none of them was positive for porins from other Gram-negative bacteria or for lipopolysaccharide (LPS). The affinity constant of these mAbs, except MPN4, was found to be in the higher range. Dot ELISA revealed that the mAbs recognized porins only in their native form. The results of inhibition ELISA using horseradish peroxidase (HRP)-conjugated MP1 suggest that the clones MP1, MP2, MP3, MPN5 and MPN6 secreted antibodies to identical epitope(s) of a 36-kDa peptide and MPN4 to a different epitope of a 35-kDa peptide. The possible applications of these mAbs were discussed.
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| 2. |
- Nandakumar, Kutty Selva, 1965-, et al.
(author)
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Diagnosis of typhoid fever : detection of Salmonella typhi porins-specific antibodies by inhibition ELISA
- 1993
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In: Clinical and Experimental Immunology. - Chichester : Wiley-Blackwell Publishing Inc.. - 0009-9104 .- 1365-2249. ; 94:2, s. 317-321
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Journal article (peer-reviewed)abstract
- Porins are highly immunogenic outer membrane proteins of Salmonella. Sera from typhoid patients contained a high level of IgG antibodies directed to porins of Salm. typhi. Since porins are highly conserved proteins, anti-porins antibodies both from typhoid patients and healthy normals reacted with porins from several Gram-negative bacteria. Therefore, in order to improve the specificity of detecting Salm. typhi porins-specific antibodies, an inhibition ELISA was developed using enzyme-conjugated MoAbs (MP1 and MPN4) specific to Salm. typhi porins. Sera from typhoid patients with positive haemoculture (16 out of 17) inhibited the binding of MP1 to porins, thus showing a positive test for typhoid, whereas sera from patients with other Gram-negative bacterial infections (n = 7) and from healthy volunteers (66 out of 67) were found to be negative. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of this assay were 94.1, 98.7, 97.8, 94.1 and 98.7% respectively. The validity of our inhibition ELISA for typhoid was higher than that of the Widal test. The diagnosis of typhoid fever as early as 3 days after the onset of fever, using a single specimen is possible.
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| 3. |
- Nandakumar, Kutty Selva, 1965-, et al.
(author)
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Influence of immunopotentiators on the antiporin immunoglobulin G subclass : distribution and protective immunity against murine salmonellosis
- 1999
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In: Scandinavian Journal of Immunology. - Chichester : Wiley-Blackwell Publishing Inc.. - 0300-9475 .- 1365-3083. ; 50:2, s. 188-194
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Journal article (peer-reviewed)abstract
- To improve the immune potential of porin (a pore-forming protein of Salmonella sp.), different immunopotentiators such as Freund's complete adjuvant (FCA), lipopolysaccharide (LPS) and polyoxydonium (PO) were evaluated by studying the nature of the protective immune response induced against murine Salmonellosis. The nontoxic, synthetic heteropolymer polyoxydonium was as good as LPS at inducing antiporin immunoglobulin G (IgG) antibodies and protective immunity. Analysis of the antiporin IgG subclass pattern revealed a preferential increase in a particular subclass based on the immunopotentiator used. Porin, alone or emulsified in FCA, elicited predominantly antiporin IgG1 antibodies, whereas LPS preferentially evoked antiporin IgG2a, IgG2b and IgG3 antibodies. Polyoxydonium induced a clear shift towards antiporin IgG2b antibodies. The significance of these antiporin IgG subclass antibodies in protection against murine Salmonellosis was studied by passive immunization and by analysing the infected mouse sera.
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