TABLE 2.

Blocking by antibodies of apical measles virus infection of polarized epithelial cells^a

MAb (400 μg/ml)	Apical supernatant		Cell lysate
	Virus titer (10−2 PFU/ml)	% Reduction of virusb	Virus titer (10−4 PFU/ml)	% Reduction of virusb
Anti-H IgA	0c	100	0.68 ± 0.07c	82
Anti-H IgG	4.55 ± 0.70c	41	3.20 ± 0.42d	15
Anti-F IgA	5.00 ± 0.28c	35	2.78 ± 0.81d	26
Anti-F IgG	4.40 ± 0.57c	43	3.20 ± 0.28d	15
Anti-N IgA	5.75 ± 0.35c	26	3.55 ± 0.35d	6
Anti-N IgG	6.90 ± 0.57d	11	3.57 ± 0.11d	6
Irrelevant IgA	8.10 ± 0.07	0	4.40 ± 0.14	0
None	7.75 ± 0.35	0	3.78 ± 0.60	0

^aExperiments were repeated on at least three occasions with similar results. Results of a representative experiment are shown. Data are means ± standard deviations (n = 3).

^bCompared to no-antibody control.

^cMean virus titers were significantly lower (P ≤ 0.002) than those from cells exposed to no antibody.

^dMean virus titers were not significantly lower (P ≥ 0.05) than those from cells exposed to no antibody.