Monoclonal antibodies to staphylococcal enterotoxins B and C: cross-reactivity and localization of epitopes on tryptic fragments

Abstract

Murine monoclonal antibodies reactive with staphylococcal enterotoxins B (SEB) and C1 (SEC1) were isolated by hybridoma techniques. Of the nine antibodies, three reacted only with SEB, two reacted with SEB and SEC1, three reacted with all subtypes of SEC, and one reacted only with SEC2 and SEC3. All of the antibodies reacted with protein blotted onto nitroceliulose from electrophoresis gels which corresponded to the enterotoxin band. Fragments of SEB and SEC1 were generated by limited digestion of the toxin with trypsin. With the immunoblot technique, four of the five antibodies reactive with SEB reacted with the tryptic fragment of molecular weight 17,000, and the five antibodies reactive with SEC, reacted with the tryptic fragment of molecular weight 14,000.

Murine monoclonal antibodies against staphylococcal enterotoxin B: production and characterization

“…Absorbances in each case (IgG~ or IgG2b) were markedly higher than in other subclasses (data not shown). The percentage of mAbs belonging to IgGzb subclass (42.85%) is much higher than those described by other authors for SEs [2,9,17] and most authors describe antibodies belonging only to lgG 1 subclass [6,10,14].…”

“…No mAb in our study reacted with the minor bands (=-15.5 kDa and = 13 kDa) reported previously by Spero et al [27] and others [13,17]. These minor bands are believed to result from nicking of the toxin by contaminating proteases at the cysteine loop [13,17]. These two bands clearly appear in SEB used for immunizing ( Fig.…”

“…Some mAbs reacted exclusively with the homologous toxin (SEB) (B5, B12 and B14), but most showed cross-reactions with SEGI. This fact described by others [2,10,17] is not surprising when the homologies in amino acid sequence of these two molecules are considered [2]. No reactions were seen against any other serovar.…”

“…There are many reports on the development and use of monoclonal antibodies (mAbs) produced against SEs [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. mAbs to all of the identified enterotoxins have been prepared [2], either specific or cross-reactive.…”

Staphylococcal enterotoxin C1‐induced pyrogenic cytokine production in human peripheral blood mononuclear cells is mediated by NADPH oxidase and nuclear factor‐kappa B

“…production in humans and primates [2,3]. Staphylococcal enterotoxins are relatively heat stable [2], and ingestion of staphylococcal enterotoxins causes emesis and diarrhea [4]. Staphylococcus aureus is also an important microorganism of bovine, ovine and caprine mastitis [5].…”