Figure 2.

“Ignorance” toward proteolipid protein (PLP) epitope #2 in TCR-PLP2 transgenic mice. (A) Thymocyte subset composition of TCR-PLP2 transgenic mice on Plp^KO or Plp^WT background. The average frequency ± SEM of CD4SP cells (upper plot), TCR-PLP2⁺ cells (Vα2⁺Vβ14⁺) among gated CD4SP thymocytes (middle), and CD25⁺Foxp3⁺ cells among gated TCR-PLP2⁺ CD4SP cells is indicated (n ≥ 8 per genotype). The bar diagrams on the right show absolute cell numbers of the respective subsets. (B) Peripheral phenotype of TCR-PLP2 transgenic mice on Plp^KO or Plp^WT background. The average frequency ± SEM of CD4 T cells (upper plot), TCR-PLP2⁺ cells (Vα2⁺Vβ14⁺) among gated CD4 T cells (middle) and CD25⁺Foxp3⁺ cells among gated TCR-PLP2⁺ CD4 T cells (lower) are indicated (n ≥ 8 per genotype). (C) Proliferation of purified CD4 T cells from TCR-PLP2 transgenic mice on Plp^KO or Plp^WT background upon in vitro stimulation with PLP_172–183. Data are from individual mice representative for n ≥ 3 each. (D) CFSE-labeled CD4 T cells from Plp^KO or Plp^WT TCR-PLP2 transgenic mice (CD45.2) were i.v. injected into Plp^WT recipients (CD45.1) that had (right) or had not (left) been immunized with PLP_172–183 the day before. Four days later, lymph node cells were harvested and analyzed by FACS. Histograms show the CFSE intensity of gated CD4⁺CD45.2⁺ cells. The filled histogram overlay is from undivided control cells in a Plp^KO recipient. Data are representative of three experiments with n = 5 each. (E) Experimental autoimmune encephalomyelitis (EAE) disease course in TCR-PLP2 Plp^WT mice upon immunization with the 12-mer peptide PLP_172–183 together with administration of pertussis toxin on days 0 and 2 (n = 14).