The present invention provides methods for producing antibodies against peptides, proteins, or such to which immune tolerance is easily established, by using antigen-binding molecules comprising a domain that binds to a molecule expressed on the surface of a cell having an immune response-suppressing function and a T cell receptor (TCR) complex-binding domain. The present invention also provides pharmaceutical compositions for use in combination with therapeutic vaccines and agents for enhancing a humoral immune response, each comprising the antigen-binding molecules as active ingredients.