Table I.

Contact with hepatocytes triggers cleavage of CSP

Experiment	Cells	Conditiona	Method for sporozoite visualization	Number of sporozoites visualizedb
1	Hepa 1-6	CD	3D11	244 ± 3
	Hepa 1-6	CD + E-64	3D11	230 ± 4
	Hepa 1-6	CD	α-N	41 ± 1
	Hepa 1-6	CD + E-64	α-N	237 ± 5
	no cells	control	α-N	80% ± 0.4
	no cells	CD	α-N	85% ± 1.1
	no cells	E-64	α-N	90% ± 4.1
	no cells	CD + E-64	α-N	84% ± 0.5
	no cells	CD + 10% serum	α-N	80% ± 3.7
2	Hepa 1-6	CD	GFP	452 ± 8
	Hepa 1-6	CD	α-N	98 ± 2
	Hepa 1-6	CD + E-64	GFP	444 ± 6
	Hepa 1-6	CD + E-64	α-N	436 ± 8

^a P. berghei sporozoites (wild type in experiment 1; GFP in experiment 2) were preincubated ± E-64, and before addition to coverslips, CD was added to the indicated samples. Sporozoites were spun onto coverslips, with or without cells as indicated, brought to 37°C for 2 min, fixed, and stained with the indicated antisera.

^bEach point was plated in duplicate, 50 fields/coverslip were counted, and the means ± SD are shown. When sporozoites were plated without cells, 100–200 sporozoites/coverslip were counted, and the percentage staining with the NH₂- terminal antiserum is shown.