Characteristics of PHA-L4, the mitogenic isolectin of phytohemagglutinin, as an ideal biologic response modifier.

Abstract

Phytohemagglutinin retains the properties of a theoretically ideal biologic response modifier in that it is available in a purely mitogenic L4 isolectin form that is stable; previously studied extensively; applicable as a simple skin test to assess immune competence and guide therapy; broadly immunostimulating with respect to both activation and proliferation of effector cell pathways; amenable to targeting maneuvers; stimulative of endogenous cytokine production; conveniently administrable by multiple routes; applicable to both active and adoptive immunotherapies; rapidly interacting irreversibly with lymphocytes; readily applied as a vaccine adjuvant; apparently nonsensitizing; relatively nontoxic, with maximum effective levels well below those for major toxicity; free from stress induction; nononcogenic; noninfectious; related to other mitogenic lectins that have augmenting therapeutic potential; compatible with other therapeutic modalities and conductive to collaborative use of other BRMs; well-suited to application as a surgical adjuvant and for prophylaxis against malignancies or infections in susceptible individuals; applicative to debilitated, immunosuppressed, and myelosuppressed patients; probably compatible with pregnancy; and potentially cost-effective.