T-Cell-Receptor-Dependent Signal Intensity Dominantly Controls CD4+ T Cell Polarization In Vivo

Abstract

Summary Polarization of effector CD4+ T cells can be influenced by both antigen-specific signals and by pathogen- or adjuvant-induced cytokines, with current models attributing a dominant role to the latter. Here we have examined the relationship between these factors in shaping cell-mediated immunity using intravital imaging of CD4+ T cell interactions with dendritic cells (DCs) exposed to polarizing adjuvants. These studies revealed a close correspondence between strength of T cell receptor (TCR)-dependent signaling and T helper-1 (Th1) vs. Th2 cell fate, with antigen concentration dominating over adjuvant in controlling T cell polarity. Consistent with this finding, at a fixed antigen concentration, adjuvants inducing Th1 cells operated by affecting DC costimulation that amplified TCR signaling. TCR signal strength controlled downstream cytokine receptor expression, linking the two components in a hierarchical fashion. These data reveal how quantitative integration of antigen display and costimulation regulates downstream checkpoints responsible for cytokine-mediated control of effector differentiation.

CD20 alternative splicing isoform generates immunogenic CD4 helper T epitopes

“…Briefly, these mice are H-2 Class I and IA Class II knockout, and their CD8 T and CD4 T cells are restricted by the sole HLA-A*0201 and HLA-DR1*0101 molecules, respectively. 11,15 For D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] (20mer) and D393-CD20 33-41 (9mer) immunization, mice were injected twice with 100 lg of D393-CD20 20mer or 50 mg of D393-CD20 9mer were emulsified in incomplete Freund adjuvant (IFA, Sigma-Aldrich). All peptide vaccinations were done subcutaneously at the base of the tail at Days 1 and 14.…”

“…2c). To further investigate the promiscuous HLA-DR binding capacity of D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] peptide and the degeneracy of T cell recognition, the reactivity of the CD4 T cell clones was evaluated against various HLA-DR-positive and D393-CD20-negative loaded with the D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] peptide. CD4 T cell clones from patient P#1 (HLA-DRB1*04 homozygote) and patient P#7 (HLA-DRB1*04 and -DRB1*11) were reactive against the HLA-DRB1*04 positive cell line FaDu loaded with the cognate peptide (Fig.…”

“…The three first amino-acids used to name these peptides are indicated in boldface. T cell lines were obtained from healthy donors' PBMCs after two rounds of in vitro stimulation in microplates with 10 lg/mL of D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] peptide. Specific responses were assessed by CD4 and IFN-g staining.…”

“…To assess the capacity of the 20mer long peptide D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] (LP) to prime a specific T cell response in vivo, we performed a peptide immunization in HLA-A2/HLA-DR1 transgenic mice and specific T cell responses were measured by ex vivo IFN-g ELISPOT assay. As shown in Figure 5a, specific CD4 T cell responses were induced in vivo against the D393-CD20 28-47 LP and against four of the six D393-CD20 derived 15mer peptides supporting that these peptides effectively binds to HLA-DR1 molecules.…”

“…24 We then evaluated the capacity of the D393-CD20 28-47 long peptide (LP) to prime HLA-A2-restricetd CTL response. To this end, mice were immunized either with the D393-CD20 [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] LP or with the HLA-A2-restricted D393-CD20 derived short peptide D393-CD20 [33][34][35][36][37][38][39][40][41] (SP). As shown in Figure 5b, higher IFN-g producing specific-CTL were detected ex vivo after immunization with the D393-CD20 28-47 LP than with the SP.…”