Studies on Typhus and Spotted Fever.
Abstract
Two major arms of protective typhus immunity have been investigated: cell mediated immunity which restricts intracellular rickettsial growth local at site of lesions and antibody-macrophage clearance of extracellular rickettsiae. Soluble factors in the supernatent fluids of leukocytes from typhus immune subjects stimulated with R. prowazekii antigen or from non-immune subjects stimulated with phytohemagglutinin had two separable effects on R. prowazekii-infected human somatic (fibroblast, Endotrhelial) or macrophage cells in vitro. Cells pulsed with stimulated supernatent fluids prior to infection caused the progressive loss of visible and viable rickettsiae without evidence of host cell damage (intracellular antirickettsial action). Cells incubated continuously in the presence of active leukocyte supernatants after infection underwent a progressive cytolysis (cytotoxic action). Treated uninfected host cells were not damaged; treated extracellular rickettsiae remained viable. Human, but not monkey, mouse or chicken cells, were responsive to supernatant fluids from human leukocytes. Strains of R. prowazekii and R. canada were susceptible to both intracellular antirickettsial and cyotoxic action; R. mooseri and R. rickettsii, to cytotoxic action only; and strains of R. tsutsugamushi, to neither. The factor(s) in the active supernatants were destroyed by heating to 56 C for 60 min and by exposure to pH 2.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1981
- Accession Number
- ADA131154
Entities
People
- Charles L. Wisseman Jr.
Organizations
- University of Maryland, Baltimore