Platforms comprising at least one lymphocyte affecting molecule and at least one molecular complex that, when bound to an antigen, engages a unique clonotype lymphocyte receptor can be used to induce and expand therapeutically useful numbers of specific lymphocyte populations. Antigen presenting platforms comprising a T cell affecting molecule and an antigen presenting complex can induce and expand antigen-specific T cells in the presence of relevant peptides, providing reproducible and economical methods for generating therapeutic numbers of such cells. Antibody inducing platforms comprising a B cell affecting molecule and a molecular complex that engages MHC-antigen complexes on a B cell surface can be used to induce and expand B cells that produce antibodies with particular specificities.