Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 14, 1995
Publication Date: N/A
Technical Abstract: Twenty two protein fractions (106 to <18 kDa) from cell lysates of Brucella abortus smooth strain 2308 and its rough mutant, strain RB51, were tested for their capacity to alter antigen presentation or the proliferation of a bovine T cell clone in response to either specific antigen or cytokines. Proliferation of the T cell clone (300B1 cells) in response to specific antigen (conalbumin) and antigen-presenting cells was not altered by prior incubation of the antigen-presenting cells with each of the 22 protein fractions of 2308 or RB51. In addition, the 300B1 cells when incubated each of the 22 protein fractions of 2308 or RB51 did not have altered proliferation in response to stimulation with interleukin 1. However, among the 22 protein fractions (106 to < 18 kDa) a group of 18 kDa proteins from 2308, but not from RB51, was found to inhibit 300B1 proliferation in response to interleukin 2. The action of the inhibitory group of proteins appeared to result from direct inhibition of the 300B1 cells and not from consumption of interleukin 2 because interleukin 2 did not bind to the proteins. The significance of the absence of these proteins in RB51 is not clear although it may be a contributing factor which results in RB51 being less virulent than 2308.