TABLE 1.

Transendothelial migration of neutrophils and monocytes in response to infection with C. trachomatis and C. pneumoniae

Treatmenta	Level of transendothelial migration (cells/HPF) ofb:
	Neutrophils	Monocytes
Mock	5.9 ± 0.6	2.9 ± 0.4
C. trachomatis L2
Live	9.4 ± 1.7	7.0 ± 1.6*
Heat inactivated	8.0 ± 1.6	4.9 ± 0.9
UV inactivated	12.0 ± 1.3	4.8 ± 0.6
C. pneumoniae TW-183
Live	22.8 ± 3.2**	12.9 ± 1.2***
Heat inactivated	10.5 ± 1.1	4.7 ± 0.6
UV inactivated	16.0 ± 1.1**	6.2 ± 1.1

^aHUVEC monolayers cultured in transwells were inoculated with C. trachomatis L2 or C. pneumoniae TW-183 at a multiplicity of infection of 1:1. Equivalent inoculum concentrations of each strain were inactivated by heat or UV light before infection (see Materials and Methods). Mock-infected cells were treated with a suspension of lysed HEp-2 cells. 

^bLevels of neutrophil and monocyte transendothelial migration were determined following 24 h of incubation as described in Materials and Methods. Data represent means ± standard errors of the means of three separate experiments. In each experiment, triplicate wells were assayed separately for each condition for neutrophil and monocyte migration. *, P < 0.05; **, P < 0.01; ***, P < 0.001.