Behaviorally conditioned enhancement of delayed-type hypersensitivity in the mouse.
Cyclophosphamide (CY), previously used to condition suppression of a number of different immune responses, was used to condition an enhancement of a delayed-type hypersensitivity (DTH) response in mice. Three weeks before sensitization with sheep red blood cells (SRBC), mice were conditioned by pairing their consumption of a saccharin solution (SAC) with injection of CY. Two, three, and four days after sensitization (Day 0), animals were reexposed to SAC and, on Day +3, they were injected with a low dose of CY. This dose suppressed the DTH response to a challenge with SRBC on Day +4 in both conditioned and control animals. Following rechallenge with SRBC on Days +11 and +18, however, DTH responses were enhanced. Conditioned mice that had been reexposed to SAC showed a significantly greater enhancement than either nonconditioned animals or conditioned mice that were not reexposed to SAC. Thus, enhancement as well as suppression of immune responses can be conditioned with CY.
Bovbjerg
D
D
Department of Microbiology (Division of Immunology), University of Rochester School of Medicine and Dentistry, New York 14642.
Cohen
N
N
Ader
R
R
D000818:Animals; D003214:Conditioning, Classical; D003520:Cyclophosphamide / Q000494:pharmacology*; D006968:Hypersensitivity, Delayed / Q000276:immunology / Q000523:psychology*; D007108:Immune Tolerance; D007114:Immunization; D008297:Male; D051379:Mice; D012439:Saccharin; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology; D013997:Time Factors
D003520:Cyclophosphamide; D012439:Saccharin