Figure 4.

Basolateral V8 protease exposure of the cells prevents dIgA stimulation of pIgR transcytosis. (A) The cells were treated according to the protocol presented in Figure 1 with the modification shown and described in the text. V8 protease was included in stages D and E in all samples. (B) Quantitation of the apical transport of pIgR in the presence of dIgA or medium alone added at stage B. n = 5; p > 0.5 for +dIgA.