The Viral Immune Response — From Interferon to Cytokine Storm
The immune response to viral infection follows a predictable cascade: infected cells detect viral nucleic acids through pattern recognition receptors (TLRs, RIG-I, cGAS-STING), triggering type I and III interferon production within hours. IFN-α and IFN-β induce an antiviral state in neighboring cells; IFN-λ (IL-29) provides mucosal-specific antiviral protection with less systemic inflammation. Inflammatory cytokines (IL-6, TNF-α, IL-1β) recruit and activate innate effector cells. Chemokines (IP-10, MCP-1, MIP-1α) direct immune cell trafficking to infected tissue. Days later, T-cell polarization cytokines (IFN-γ, IL-4, IL-5, IL-10) reflect the adaptive immune response. When this cascade is appropriately calibrated, the virus is cleared with minimal tissue damage. When dysregulated — as in severe COVID-19, influenza pneumonia, or EBV-associated HLH — the cytokine storm causes the immunopathology that determines outcome. Our panels capture each phase of this cascade from a single 25 µL sample.
Key Immune Dimensions Captured
- Interferon response (hours 0–24): IFN-α2a, IFN-β, IFN-γ, IFN-λ1/IL-29 — the four interferons that determine early viral control. The Interferon 4-Plex is the dedicated subtyping panel.
- Inflammatory cascade (hours 6–72): IL-6, TNF-α, IL-1β, IL-8 — core acute-phase cytokines. Elevated levels correlate with disease severity in COVID-19, influenza, and other viral infections.
- Immune cell recruitment (hours 12–96): IP-10, MCP-1, MIP-1α — chemokines directing monocytes, NK cells, and T cells to infected tissue. IP-10 is one of the most consistently elevated chemokines in viral infection.
- Adaptive polarization (days 3–14): IFN-γ, IL-4/IL-5, IL-10, IL-17A — reflecting the transition from innate to adaptive immunity and T-cell response quality.