Production of anti-neurotoxin antibody is enhanced by two subcomponents, HA1 and HA3b, of Clostridium botulinum type B 16S toxin–haemagglutinin

Abstract

Clostridium botulinum type B strain produces two forms of progenitor toxin, 16S and 12S. The 12S toxin is formed by association of a neurotoxin (NTX) and a non-toxic non-haemagglutinin (NTNH), and the 16S toxin is formed by conjugation of the 12S toxin with a haemagglutinin (HA). HA consists of four subcomponents designated HA1, HA2, HA3a and HA3b. When mice were immunized with formalin-detoxified NTX, 12S or 16S, a significantly greater amount of anti-NTX antibody (Ab) was produced in the mice injected with 16S than in NTX-or 12S-injected mice. Immunization with NTX mixed with HA1 and/or HA3b also increased the anti-NTX Ab production, whereas NTX mixed with HA2 did not, indicating that HA1 and HA3b have adjuvant activity. This was further confirmed by immunizing mice with human albumin (Alb) alone or Alb mixed with either HA1 or HA3b. When mouse-spleen cells were stimulated with NTX, 16S or different HA subcomponents, 16S, HA1, HA3b and the mixture of HA1 and HA3 significantly increased interleukin 6 (IL6) production compared with NTX alone. Transcription of IL6 mRNA was low after stimulation with NTX alone, but increased to 16S-stimulation levels when NTX was mixed with HA1 or HA3b. In flow cytometry using labelled Abs against CD3 and CD19, the percentage of CD19 cells was higher following stimulation with 16S or NTX mixed with HA1 or HA3b compared with stimulation with NTX. The percentage of CD3 cells remained unchanged. These results suggest strongly that HA1 and HA3b demonstrate adjuvant activity via increasing IL6 production.

Expression of the Clostridium botulinum A2 Neurotoxin Gene Cluster Proteins and Characterization of the A2 Complex

“…The biological and structural roles of the complex proteins are not completely characterized, although it has been proposed that they serve the role of protecting BoNT from harsh conditions, including pH, salt, temperature, and digestive enzymes, and that they assist BoNT translocation across the intestinal epithelial layer (2,6,17). A recent report indicated that the nontoxic proteins serve as adjuvants and contribute to the immunogenicity of BoNT/A (25).…”

Development of Enzyme-Linkage Immunosorbent Assay Against Type B of Clostridium Botulinum: A Preliminary Study

“…These considerations have led the researchers to develop a more practical method of testing by applying the principles of immunodiagnostics such as ELISA. Lee et al (2005), Atassi (2006), and Keller (2008) suggested that if immunodiagnostics need to be developed, it would be better if using antibodies produced from modified C. botulinumintact toxin. They found that "home-made vaccine" from native C. botulinum antigens were more immunogenic and more protective than those of commercial antigens (Keller, 2008).…”

Botulinum neurotoxin-A treatment of lower urinary tract symptoms in multiple sclerosis

“…39 Various factors might affect BONT-A immunogenicity. They include product-related factors, such as manufacturing process and antigenic protein load (accessory proteins have been shown to increase the immunological response to NTX-A [40][41][42] ), as well as treatment-related factors, such as overall toxin dose and prior vaccination or exposure.…”