Evaluation of antibody-dependent cell cytotoxicity using lactate dehydrogenase (LDH) measurement

In order to improve therapeutic antibodies efficacy in cancer patients, several strategies were developed. One of these strategies consists in the enhancement of effector functions. Antibody-dependent cellular cytotoxicity (ADCC) was shown to mediate the activity of several therapeutic antibodies through interaction of the constant fragment (Fc) with immune cells. The interactions of Fc fragment can be modulated by engineering through modifications of the carbohydrate moieties or through modifications of some critical amino acids for its binding. Such modifications have to be studied in an in vitro assay to evaluate their impact on the regulation of effector functions. Here, we described a method to evaluate ADCC using a nonradioactive assay based on the measurement of lactate dehydrogenase (LDH) release. NK cells were purified by negative immunomagnetic selection and used as effector cells to trigger ADCC against specific target tumor cells. The LDH release measurement from lysed cells is performed after 4 h incubation. This method can replace the (51)Cr release assay since it is less restrictive and highly sensitive.