Figure 1.

(A ) Hierarchy of lymphocytic choriomeningitis virus (LCMV) epitope‐specific memory populations which expand upon vaccinia virus (VV) infection. Determined by private specificity of the T‐cell receptor (TCR) repertoire of each individual mouse, NP₂₀₅(50% of mice) > GP₃₄(23%) > GP₁₁₈(15%). (B) Structural modeling demonstrates similar structures evident in areas important for TCR interaction between VV a11r₁₉₈ and LCMV GP₁₁₈, LCMV GP₃₄, LCMV NP₂₀₅, and VV e7r₁₃₀. Using the concept of molecular mimicry, LCMV epitopes were identified that induced cross‐reactive CD8⁺ T‐cell responses recognizing the VV a11r₁₉₈ epitope (shown in green). The arrows mark positions 4, 7 (white), and 6 (yellow), which are important for TCR interaction. For modeling 3‐D structures of putative peptide‐H‐2K^b complexes, we used X‐ray coordinates of the crystallized TCR(2C)–dEV8–H‐2K^b (PDB access number 2CKB). Using Swiss‐PDB Viewer software (GlaxoSmithKline R & D, Geneva, Switzerland), we mutated dEV8 to simulate the peptides whose sequences are shown in (B). The modified variants with minimal rotamer penalties were subjected to an energy minimization protocol. For graphical presentation of the simulated peptide‐H‐2K^b complexes, PyMol software (DeLano scientific LLC, San Carlos, California) was utilized. The H‐2K^b‐restricted ovalbumin epitope, SIINFEKL, is shown as the actual crystal structure adapted from PDB access number 1VAC (185).