Immune Modulation by Coxiella burnetii: Characterization of a Phase 1 Immunosuppressive Complex Differentially Expressed among Strains
Abstract
Coxiella burnetii, the etiological agent of Q fever, possesses immunomodulatory activity which positively and negatively regulates host immune responses. We wish to determine the Coxiella strain differences and the chemical nature of cellular components suppressing lymphocyte responsiveness. The bacterial components responsible for the immunomodulatory activity are associated with phase I cells. In its natural state, the phase I cell- associated, immunosuppressive complex (ISC) was resistant to chemical and enzymatic treatment. The ISC was inactivated and rendered accessible by chloroform-methanol (CM) (4:1) extraction of phase I cells which produced a CM residue (CMRI) and CM extract (CME). The suppressive components in either CMRi or CME did not induce ISC activity in the host when injected separately. Reconstitution of of the CMRI with CME prior to injection produced the same pathological reactions characteristic or phase I cell. The CMRI suppressive component was sensitive to alkali, acid, periodate, lysozyme, and neuraminidase, but resistant to lipase and protease. An active component of CMRI was attached to the cell matrix by disulphide bonds. The amphipathic, lipophilic, CME suppressive component was ubiquitously distributed in procaryotes and eukaryotes because ISC activity of CMRI was regained after association with reagent-grade lipids and different CMEs. The ISC was expressed by phase I stains with smooth lipopolysaccharide (LPS) but not only by phase II strains with rough LPS. Reprints. (aw)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA201144
Entities
People
- David W. Waag
- Jim C. Williams
Organizations
- United States Army Medical Research Institute of Infectious Diseases