Major histocompatibility complex class II-CD4+ T-cell receptor complex (CRM197-specific) (MHC II-TCR (CRM197))

The MHC class II – CD4+ T cell receptor complex recognizing CRM197-derived peptides is a pivotal immunological assembly required for the success of conjugate vaccines (Pichichero, 2013 [1]). CRM197, a non-toxic mutant of diphtheria toxin, serves as a carrier protein that provides T-cell epitopes for polysaccharide antigens (Bröker et al., 2011 [3]). Upon vaccination, antigen-presenting cells process CRM197 and display its peptides on MHC class II molecules to be recognized by specific CD4+ T-cell receptors (TCRs) (Avci et al., 2011 [2]). This recognition triggers the activation of T helper cells, which in turn provide the necessary signals for B cells to undergo isotype switching and develop into high-affinity memory B cells (Stefanetti et al., 2022 [4]). This target is central to the prevention of infections caused by encapsulated bacteria, such as Streptococcus pneumoniae and Neisseria meningitidis (Avci et al., 2011 [2]). Therapeutic agents targeting this complex include widely used conjugate vaccines like Prevnar 13 and Menveo (Stefanetti et al., 2022 [4]).

Other names

CRM197-specific T-cell receptorMHC-II/CRM197 peptide complexDiphtheria toxin CRM197-specific TCRCD4+ TCR-MHC II (CRM197)CRM197-specific CD4+ T-cell receptor

Activation of CD4+ T helper cells through TCR recognition of MHC-II-presented CRM197 peptides, facilitating B-cell isotype switching and memory formation (Pichichero, 2013; Avci et al., 2011).