Many complex natural products contain immune modulating compounds that may rapidly alter immune cell function, migration, and activation status. It is often desirable to verify that a potent immunomodulatory product or compound does not, by itself, induce cell division (proliferation). If a product is capable of inducing cell proliferation directly, it can raise safety concerns. Thus, the basic assay doubles as a safety evaluation as well.
Studying the immune response may require an immune challenge, whether in a clinical immune study or in lab tests.
To examine immune modulation by natural products ideally a panel of tests is applied, where each test asks specific questions.
When studying the immune response to an immune challenge in the laboratory, we add a mitogen to trigger a complex set of cellular cross-talk, activation, and cell proliferation. The mitogen Pokeweed Mitogen (PWM) serves as one model for this type of challenge, as it requires communication between monocytes/macrophages, T and B lymphocytes to engage in a robust response.
The cell cultures are treated with serial doses of natural product before adding PWM to initiate the immune reaction. If the natural product triggers cellular re-programming and activation events, the cells may respond differently to the PWM challenge.
This test is ideally combined with cytokine testing of the culture medium as well.