Fig. 4

JAK/STAT Pathway Cooperates with Glucocorticoid Receptor-Mediated Signaling to Regulate Infection-Responsive irg1 Expression within Macrophage-Lineage Cells

(A–C) Expression of irg1 within infected DMSO (control)-, AG490 (0.5 mM)-, and STAT3 inhibitor peptide (62.5 µM)-treated larvae, respectively, at 1 hpi.

(D) Quantification of irg1⁺ cells within individual infected larvae treated with DMSO, AG490 (0.5 and 1.0 mM), or STAT3 inhibitor peptide (62.5 and 125 µM), at 1 hpi (mean ± SD).

(E and F) Expression of irg1 within infected control MO-injected and Stat3-depleted larvae, respectively, at 1 hpi.

(G) Quantification of irg1⁺ cells within individual infected larvae as shown in (E) and (F) (mean ± SD).

(H and I) Expression of cebpβ within infected control MO-injected and Stat3-depleted larvae, respectively, at 1 hpi.

(J and K) Immunofluorescence detection of phosphorylated Stat3 (Stat3-P, Alexa 568) and Mpeg1/EGFP (Alexa 488) within the midbrain/hindbrain region of PBS-injected and infected Tg(mpeg1:EGFP) larvae, respectively, at 1 hpi. Yellow asterisks mark macrophage-lineage cells containing phosphorylated Stat3.

(L) Quantification of Stat3-P⁺ macrophage-lineage cells within the midbrain/hindbrain region of individual larvae as shown in (J) and (K) (mean ± SD). Region assessed, 100 µm from dorsal-most surface of midbrain/hindbrain (512 × 512, 50 z sections at 2 µm).

(M and N) Expression of irg1 within infected control MO-injected and Stat3 + Nr3c1-depleted larvae, respectively, at 1 hpi.

(O) Quantification of irg1⁺ cells within individual infected control MO-injected, Stat3-depleted, Nr3c1-depleted, and Stat3 + Nr3c1-depleted larvae, at 1 hpi (mean ± SD).

(P) Schematic illustrating proposed regulation of infection-responsive irg1 expression within macrophage-lineage cells. Asterisks, arrows, and arrowheads mark blood-specific, liver-specific, and gut-specific cebpβ expression, respectively. All views anterior to left. Numbers represent frequency of larvae with displayed phenotype. Scale bar, 100 µm in (A). p < 0.0001. See also Figure S4.