Non-specific defence against Pseudomonas infections--phagocytosis of Pseudomonas by human leukocytes

Abstract

The defence mechanism against infection with Pseudomonas aeurginosa was investigated from the viewpoint of phagocytosis by human PMNs. A study of the effect of antibody, complement, endotoxins and exsoenzymes on phagocytosis by PMNs was under taken by the Quie's method, as follows:1) Phagocytosis of Pseudomonas aeurginosa serotype G was inhibited by LPS from the same serotype, while that with different serotypes C and E was not.2) OEP from Pseudomonas aeruginosa serotype G did not inhibit the phagocytosis of Pseudomonas aeurginosa serotypes G, C and E.3) Elastase from Pseudomonas aeruginosa IF03455, protease from Pseudomonas aeruginosa IF03080 and slime from Pseudomonas aeruginosa IF03455 inhibited the phagocytosis of Pseudomonas aeruginosa serotype G. Especially, elastase most potentiality inhibited the phagocytosis of Pseudomonas aeruginosa and complement activity.4) OEP antibody enhanced the phagocytosis. The serum absorbed by Pseudomonas aeruginosa serotype G did not develop the phagocytosis of Pseudomonas aeruginosa serotype G.5) Pathway of activation of complements on phagocytosis of Pseudomonas aeruginosa as well as Staphylococcus aureus by leukocytes was examined. Phagocytosis of Staphylococcus aureus was inhibited by both EDTA and EGTA, while that of Pseudomonas aeruginosa was not by EGTA. This result suggests that the alternate pathway of activation of complements relates to the phagocytosis of Pseudomonas aeurginosa.6) When OEP antibody titer of opsonin was low, Anti-pseudomonas globulin (OEP-HA titer 256x) enhanced the phagocytosis of Pseudomonas aeruginosa.However, as OEP antibody titer of opsonin became higher, Anti-pseudomonas globulin did not influence the activity in phagocytosis of Pseudomonas aeruginosa by PMNs.