The CD4 coreceptor interacts with non-polymorphic regions of major histocompatibility complex class II molecules on antigen-presenting cells and contributes to T cell activation .
the cd4 coreceptor interacts with non-polymorphic regions of major histocompatibility complex class ii molecules on antigen-presenting cells and contributes to t cell activation .
O B-protein_molecule I-protein_molecule O O B-protein_domain_or_region I-protein_domain_or_region O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O B-cell_type I-cell_type O O O B-other_name I-other_name I-other_name O