Screening of Immunomodulatory Drugs

Screening of Immunomodulatory Drugs

1. Definition, rationale & the immune targets that assays probe

• Immunomodulator screening = the preclinical bench-and-animal battery used to detect whether a test compound suppresses (immunosuppressant) or augments/restores (immunostimulant) an immune response, and to grade its potency against reference standards (Vogel V2 Part IX, "Methods for Testing Immunological Factors", pp.2091–2113).
• The immune response is functionally partitioned, and each arm has its own validated read-out assay — a screening cascade typically samples ≥ 3 arms to profile a compound (Vogel V2 Part IX, pp.2091–2173):
  • Humoral (antibody-mediated) immunity — B-cell/plasma-cell output → plaque-forming-cell (PFC) assay to sheep red blood cells (SRBC); classically also the haemagglutination antibody titre ⚠ (see §9 gap — HA-titre not detailed in the provided chapters).
  • Cell-mediated immunity (CMI) — T-cell effector function → delayed-type-hypersensitivity (DTH) footpad swelling; mitogen-/MLR-driven lymphocyte proliferation; leucocyte-migration-inhibition ⚠ (LMI not detailed in the provided chapters — §9 gap).
  • Non-specific / innate & reticuloendothelial (RES) function — macrophage/neutrophil oxidative burst and phagocytosis → macrophage chemiluminescence; carbon-clearance phagocytic index ⚠ (carbon-clearance not in the provided chapters — §9 gap); neutrophil-adhesion.
  • Effector hypersensitivity reactions — mast-cell/IgE-mediated (anaphylaxis, Arthus) as models of drug-modifiable allergic inflammation.
• Why animal + in-vitro tiers are both needed: in-vitro assays (enzyme, cell-culture proliferation) allow high-throughput lead selection with small compound amounts; whole-animal models test the compound in an intact, cytokine-networked immune system, which no single cell assay reproduces (SK Gupta Ch.33, pp.501–502 — "animal studies … tested in intact biological systems"; Vogel V2 Part IX, p.2091).
• A recurring caveat threaded through both sources: mouse models of inflammatory/immune disease correlate poorly with human conditions — SK Gupta's revised chapter explicitly shifts emphasis toward rat models for superior pain behaviour and surgical tractability (SK Gupta Ch.33, p.502, citing Seok et al., PNAS 2013).