ASSAY – ADCP
HUMAN CELL LINE BASED
Antibody Dependent Cellular Phagocytosis (ADCP) Assays
Phagocytosis is an immunologic mechanism involved in apoptosis, necrosis, infection and tumour conditions that is mediated by leukocytes such as macrophages, DCs, neutrophils, etc. One of the types of phagocytosis is antibody-dependent cellular phagocytosis (ADCP) in which antibody-opsonised target cells activate phagocytes via Fc-FcR binding. This leads to internalization and degradation of the target cell which is a useful mechanism in infection and tumour biology, and the basis of many antibody-based drugs.
In vitro ADCP phagocytosis Assays
Our in-house phagocytosis assay using cell line based macrophages is adapted to an ADCP assay where the target cell is co-cultured with phagocytes. In addition to generating microscopy based co-localisation readings of target cell and phagocyte (representing cell attachment) we generate flow cytometry based phagocytosis readings in which the values of the phagocytosed vs non-phagocytosed populations can be quantified. In this model the target cell can be an adherent or a suspension cell.
ADCP is important in studies of various therapeutic areas and biological pathways:
- Tumour biology and oncology
- Immuno oncology
- Tissue damage and cell death
In recent years much attention has been given to in vitro ADCP models in oncology.
Cell Line Based Approach
We use myeloid and lymphocytic cell lines for various immune response assays such as dendritic cell maturation, T cell activation, phagocytosis, etc. We are among the few groups who can generate and demonstrate the use of dendritic cells and macrophages (including M1 and M2) from monocytic cell lines and T cells in activation studies. Conventionally dendritic cells are generated from primary monocytes or bone marrow and T cells or monocytes are separated from primary PBMCs from human donors. The use of cell lines in the initial stage offers a consistent reference assay prior to using primary human cells. Primary human cells used in the initial stage can be variable, expensive, time consuming, and often inconclusive.