Abstract
Peripheral blood leukocytes from rabbits were used in one‐way mixed leukocyte reaction (MLR), When the rabbits were injected with basic encephalitogenic protein in Freund's complete adjuvant (FCA), an impairment of the MLR occurred, partly resembling that previously described in certain human diseases. This impairment was found to be due to an effect on both the stimulating and the responding phase of the MLR. Similar, but much weaker effects were seen when cells from rabbits injected with saline in FCA were studied. Sera from rabbits with experimental autoimmune encephalomyelitis reduced the two‐way MLR between two normal rabbits, but no clear‐cut effect was seen with sera from rabbits injected with saline in FCA.