Journal: Advanced Science
Article Title: High‐Affinity Superantigen‐Based Trifunctional Immune Cell Engager Synergizes NK and T Cell Activation for Tumor Suppression
doi: 10.1002/advs.202310204
Figure Lengend Snippet: Identification of SEB variants with enhanced immunoreceptor binding affinity. a) The stepwise illustration of the SEB yeast library establishment. The library was incubated with 1 µ m of recombinant human CD28, and the population exhibiting a higher binding affinity to human CD28 was sorted through flow cytometry. The sorted library was then amplified, resulting in the production of 4 subsequent generations of libraries. b) The binding affinity of all the sorted SEB libraries to mouse and human CD28 as measured by flow cytometry. c) Missense mutations were identified from 9 single clones selected from the S4 SEB yeast library. d) In the SEB structure (pdb: 1sbb), the wild‐type SEB (upper panel) and the 9 mutated amino acids on the S4 clone (SEB #3) (lower panel) are shown in the pink sticks using PyMol. e) Schematic illustration demonstrating the potential hindrance effect of the D55G mutation on TCR interaction and downstream NFAT signaling. f) The binding affinity of all the SEB variants toward the immunoreceptors (CD28, CD80, CD86, and MHC‐II) was tested using flow cytometry. The mean fluorescence of protein binding on the surface‐displayed population is shown.
Article Snippet: For the other immunoreceptors binding affinity tests, induced yeast cells were incubated with 1 µ m human Fc tagged mouse CD28 recombinant protein (SinoBiological, 50103‐M02H), 5 µ m His tagged human CD80 recombinant protein (SinoBiological, 10698‐H08H), 5 µ m His tagged mouse CD80 recombinant protein (SinoBiological, 50446‐M08H), 5 µ m His tagged human CD86 recombinant protein (SinoBiological, 10699‐H08H), 5 µ m His tagged mouse CD86 recombinant protein (SinoBiological, 50068‐M08H), 2 µ m His tagged human HLA‐DRA recombinant protein (Cusabio, CSB‐EP360793HU), 0.5 µ m human Fc tagged human CD2 recombinant protein (SinoBiological, 10982‐H02H), 2 µ m His tagged mouse CD2 recombinant protein (SinoBiological, 50537‐M08H), 0.5 µ m human Fc tagged human CD58 recombinant protein (SinoBiological, 12409‐H02H), and 0.5 µ m human Fc tagged mouse CD48 recombinant protein (SinoBiological, 50415‐M02H) at 4 °C for 2 h. Yeast cells were washed with PBS once and stained with the anti‐human IgG Fc antibody (Abcam, ab131612), the anti‐His tag antibody (Biolegend, 362603), and the anti‐HA tag antibody (Biolegend, 682404) at 4 °C for 30 min.
Techniques: Binding Assay, Incubation, Recombinant, Flow Cytometry, Amplification, Clone Assay, Mutagenesis, Fluorescence, Protein Binding