|
| Type I IFN | Type II IFN | Type III IFN |
|
| Source of stimulation | Bacterial and viral components [13] | IL-12 and IL-2 [14] | Viral components [15] |
| Source of production | Every cell in the body (leukocytes, fibroblasts, and endothelial cells) [17] | T-cells (especially CD4+ T-cells) [17] | Epithelial cells [18] |
| Type | IFN-α, IFN-β, IFN-κ, IFN-ε, IFN-ω, and IFN-τ [10] | Only IFN-γ [11] | IFN-λ1 (IL-29), IFN-λ2
(IL-28A), IFN-λ3 (IL-28B), and
IFN-λ4 [12] |
| Receptor | IFNAR1 and IFNAR2 [10] | IFNγR1 and IFN-γR2 [11] | IL10R2 (also called CRF2-4) and IFNLR1 (also called CRF2-12) [12] |
| Intracellular signaling | JAK | JAK1, TYK2 [20] | JAK1, JAK2 [20] | JAK1, TYK2 [21] |
| STAT | STAT1, STAT2 [20] | STAT1 [20] | STAT1, STAT2 [21] |
| Translocation complex to nucleus | (i) IFN-stimulated gene factor 3 (ISGF3) [20]
(ii) STAT1-STAT1 homodimers [20] | STAT1-STAT1 homodimers [20] | (i) IFN-stimulated gene factor 3 (ISGF3) [22]
(ii) STAT1-STAT1 homodimers [22] |
| Promoters stimulated | (i) IFN-stimulated response element (ISRE) [20]
(ii) IFN-γ-activated site (GAS) [20, 23] | IFN-γ-activated site (GAS) [20] | (i) IFN-stimulated response element (ISRE) [22]
(ii) IFN-γ-activated site (GAS) [22] |
| Function in tuberculosis | | (i) Induce the immunosuppressive/macrophage-deactivating cytokine, IL-10 [24, 25]
(ii) Either block [24, 25] or polarize [26] Th1 immune response
(iii) Suppress host-protective cytokines such as TNF-α, IL-12, and IL-1β [24, 25]
(iv) Limit the expression of IFN-γ-induced MHC class II on APCs [29]
(v) Synergistic effect with IFN type II promoting protection against Mtb infection in mice [8]
(vi) Inhibition of alternative macrophage activation [27] | (i) Stimulate Th1 type cytokines [8]
(ii) Recruitment of T-cells [8]
(iii) Induction of expression of MHC class II molecules and augmentation of APCs [8]
(iv) Promotes cellular proliferation, cell adhesion, apoptosis, and autophagy [30] | Not essential for Mtb infection control, but may contribute to the modulation of Th1/Th2 immune responses [25] |
| Use in diagnosis | No report | IFN-γ release assays (IGRAs) [43–55] | No report |
| Use in therapeutics | Adjunctive therapy with IFN-α by aerosol route to treat pulmonary TB. Precaution need to be taken while treating immunodeficiency patients as it may lead to TB reactivation [26, 27, 64–70] | Adjunctive therapy with IFN-γ by aerosol or subcutaneous routes to treat pulmonary TB or extrapulmonary TB [58–63] | No report |
| Use in vaccine | Combination of IFN-α and IFN-γ enhance production of IL-12 which induce CD4+ T-cell Th1 polarization [71] | (i) Use as adjuvant to induce Th1 immunity [73, 74]
(ii) Development of fusion proteins, genetic constructions, or live vectors expressing cytokines related to the induction of IFN-γ [75–113] | No report |
|
