CD4+ T cell receptor recognizing CRM197-derived peptides (CRM197-specific TCR) (CRM197-specific TCR)

The CD4+ T cell receptor (TCR) recognizing CRM197-derived peptides is a critical mediator of the adaptive immune response to conjugate vaccines. CRM197 is a non-toxic mutant of the diphtheria toxin that serves as a carrier protein, providing the necessary T-cell epitopes to convert T-cell independent polysaccharide antigens into T-cell dependent ones [1]. Upon administration of a conjugate vaccine, antigen-presenting cells internalize the complex and process the CRM197 protein into peptides for presentation on MHC class II molecules [2]. These peptide-MHC complexes are specifically recognized by the TCRs of CD4+ T cells, leading to their activation and differentiation into follicular helper T cells [3]. These activated T cells then provide essential signals to B cells, facilitating isotype switching and the generation of high-affinity, long-term memory antibodies against the conjugated polysaccharides [4]. This mechanism is fundamental for the efficacy of vaccines against major bacterial pathogens like Streptococcus pneumoniae and Neisseria meningitidis, especially in infants [5].

Other names

CRM197-specific T-cell receptorCross-reacting material 197-specific TCRDiphtheria toxin CRM197-specific TCR

Recognition of CRM197-derived peptides presented on MHC class II molecules by CD4+ T cells, leading to T cell activation and subsequent B cell help for antibody production.