Conjugated peptides include a first peptide component which is an antigen associated with autoimmune disease, allergy, asthma or transplantation rejection and binds to an antigen-specific receptor on a T cell, and a second peptide component which corresponds to an "antigen presenting molecule" namely, a peptide binding to a T cell surface receptor, which would normally promote T cell activation when the first peptide is bound to its antigen-specific T cell receptor. However, in this invention, the second peptide component has an amino acid sequence which is a modification of an antigen presenting T cell binding peptide, such modification blocking or inhibiting the engagement of receptor sites on the T cell surface (other than the antigen-specific T cell receptor). As a result of the inhibition/blocking, T cell activation is prevented, and is directed through antigen-specific T cell receptor occupation, without T cell activation, leading to antigen-specific T cell anergy and cell death. Administration of the conjugated peptide to an animal, e.g., human, will provide that animal with protection against the disease associated with the first peptide component, resulting from the elimination of the T cells bearing the antigen-specific receptors for that antigenic peptide. The conjugated peptides of this invention provide antigen-specific protection without impairing the immune response to other antigens, including pathogens.