Immune cells (modulated via ex vivo cell–cell contact and paracrine signaling)

The term provided does not refer to a single molecular target or receptor but rather describes a complex therapeutic modality known as ex vivo cellular therapy or adoptive cell transfer. In this approach, immune cells such as T cells, Natural Killer (NK) cells, or Dendritic cells are isolated from a patient or donor and stimulated outside the body. This stimulation occurs through direct cell-to-cell contact—often involving the engagement of the T-cell receptor (TCR) by major histocompatibility complex (MHC) molecules—and paracrine signaling via exogenous cytokines that direct cell differentiation and proliferation (June et al., 2018, Science). This process is fundamental to the production of advanced therapies like CAR-T cells, where cells are engineered and expanded to recognize specific tumor antigens. Once re-infused, these modulated cells exert their effects by secreting further paracrine factors and engaging in direct contact with target cells to induce apoptosis or suppress inflammation (Galipeau & Sensébé, 2018, Nature Biomedical Engineering). While highly effective in treating certain hematologic malignancies and potentially autoimmune conditions, this modality is associated with significant safety challenges, including systemic inflammatory responses like cytokine release syndrome (Shimabukuro-Vornhagen et al., 2018, Journal for ImmunoTherapy of Cancer).

Other names

Ex vivo cell therapyAdoptive cell transferCell-based immunotherapyAdoptive immunotherapyEx vivo primed immune cells

Therapeutic cells are harvested and manipulated ex vivo through direct physical interaction with other cells (e.g., antigen-presenting cells) or exposure to secreted paracrine factors (e.g., cytokines like IL-2, IL-7, or IL-15) to enhance their activation, expansion, or regulatory functions before re-infusion into the patient.