Figure 2From: Transcellular migration of neutrophil granulocytes through the blood-cerebrospinal fluid barrier after infection with Streptococcus suis Effect of S. suis and TNFα on PMN transmigration through PCPEC and barrier function. (A, B, C) PCPECs were infected with S. suis strain 10 and the non-encapsulated mutant strain 10 Δcps (MOI 10) or stimulated with TNFα (10 ng/ml) as described in Methods. PMNs were applied after 24 h of stimulation to the basolateral side of PCPEC. Effects on barrier function were measured by TEER (A) and TR-dextran flux (B) of PCPEC monolayers. The TEER results are expressed as absolute TEER values (Ω × cm2). (A) For simplification only TEER values of IL-8-treated PCPECs are shown because they did not differ from TEER values of PCPEC cultures without IL-8. TEER was measured before stimulation, 24 h later that was directly before PMN transmigration and after 4 h of PMN transmigration. #, P value of < 0.001, compared to time point before.(B) The TR-dextran flux was measured in the basolateral-to-apical direction (upper to lower compartment) with or without S. suis infection, respectively, and TNFα stimulation and is expressed as percentage of tracer in the basolateral (upper) compartment. TR-dextran flux was determined after 4 h of PMN transmigration. In indicated samples IL-8 (10 ng/ml) was used as chemoattractant. Data are shown are mean ± SD for four independent experiments, each performed in triplicate. *, P value of < 0.05 compared to corresponding control PCPECs without IL-8 stimulation. §, P value of < 0.05 compared to corresponding control PCPECs with IL-8 stimulation. (C) BCECF-loaded PMNs were applied after 24 h of stimulation to the basolateral side of inverted PCPEC in a PCPECs:PMNs ratio of 1:10. In indicated samples IL-8 (10 ng/ml) was used as chemoattractant. The number of PMNs was fluorometrically measured after 4 h of transmigration. PMN transmigration is expressed% PMN transmigration from totally applied PMNs. Data are shown as mean ± SD for four independent experiments, each performed in triplicate. *, P value of < 0.0001 compared to PCPEC without IL-8; #, P value of < 0.0001, compared to corresponding control PCPEC +/- IL-8; §, P value of < 0.0001 compared between different stimuli.Back to article page