Fig. 8
M. circinelloides promotes the recruitment and apoptosis of macrophages in the infection site. (A) Representative serial sections of zebrafish head kidneys challenged with PBS, 2.5×105 R7B spores/fish and 107 (high dose, HD) NRRL spores/fish at 16 hpi and immunostained with anti-Lcp1, anti-Mpx, and anti-active Casp3 antibodies. Infiltrated leukocytes (black arrows) at 16 hpi were PAS+, Lcp1+ and most of them Casp3+ in the fish infected with the virulent strain (R7B) and the HD of the avirulent NRRL strain. Scale bars 20 µm. (B) Quantification of Lcp1+, Mpx+, and Casp3+ cells is shown as the mean ± SEM of the immunostained area/total area of 4 randomly distributed optical regions from 4 fish at ×200 magnification. *P<0.05.