IMMUNOLOGIC STUDIES OF ANTHRAX. IV. EVALUATION OF THE IMMUNOGENICITY OF THREE COMPONENTS OF ANTHRAX TOXIN
Abstract
Three components of anthrax toxin (edema factor, protective antigen and lethal factor) were separated and tested singly at three dose levels and in factorial combination (27 treatments) to determine their efficacy as immunogens in a resistant host (rat) and in a susceptible host (guinea pig). Each treatment was evaluated as an immunogen by five criteria: (1) protection of the host against challenge, (2) influence on the number of bacilli/milliliter of blood at death, (3) change in the units of toxin/milliliter of blood at death, (4) a development of antibody titer (Ouchterlony) and (5) units of toxin neutralized/milliliter of blood. These evaluations showed that (1) the LF component was highly immunogenic in rats against either toxin or spore challenge and in guinea pigs against spore challenge; (2) the PA component was immunogenic against spore challenge in rats and guinea pigs, but completely ineffective against toxin challenge in rats; (3) the EF component alone was nonimmunogenic; (4) the effects of LF and PA were additive and (5) EF added to LF, PA or LF-PA combinations interacted significantly with LF to increase resistance in the rat, but was not additive in resistance in the guinea pig. The number of organisms/ milliliter of terminal blood decreased as resistance to establishment of disease increased. The units of toxin/milliliter of terminal blood were closely related to the number of bacilli/milliliter of blood at death. Only 17% of the prechallenge serum of guinea pigs, principally among the LF treatments, produced antigen antibody precipitin lines on Ouchterlony plates.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0640357
Entities
People
- B. G. Mahlandt
- B. W. Haines
- F. Klein
- R. E. Lincoln
- R. H. Friedman
- W. I. Jones Jr.
Organizations
- United States Army Biological Warfare Laboratories