FIG 1.

CLDN4 plays a role in PRRSV infection. (A) Changes in TJ mRNA expression during TA-12 infection of MARC-145 cells. MARC-145 cells were infected with PRRSV TA-12, and the mRNAs were collected at 0, 12, 24, 36, and 48 hpi. The levels of CLDN3, CLDN4, OCLN, ZO-1, ZO-2, and JAM-1 mRNA were measured by relative qPCR. (B) Western blot analysis of the effects of PRRSV infection on CLDN4. MARC-145 cells were infected with TA-12, and the cells were collected at 12, 24, 36, and 48 hpi. The cellular proteins were analyzed by Western blotting using anti-CLDN4, anti-CLDN3, and anti-N antibodies. (C) Changes in CLDN4 expression in PAMs during TA-12 infection. PAMs were infected with PRRSV TA-12, and the cells were collected at 0, 12, 24, 36, and 48 hpi. The levels of mRNA and protein expression of CLDN4 were measured by relative qPCR and Western blotting, respectively. β-Actin was used as an internal control. The asterisks indicate significant differences relative to the control values: *, P < 0.05; **, P < 0.01 (Student's t test).