scholarly journals Phagocytosis of Vibrio cholerae O139 Bengal by Human Polymorphonuclear Leukocytes

1999 ◽  
Vol 6 (2) ◽  
pp. 276-278 ◽  
Author(s):  
M. John Albert ◽  
Firdausi Qadri ◽  
Nurul A. Bhuiyan ◽  
Shaikh M. Ahmad ◽  
M. Ansaruzzaman ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Vibrio Cholerae ◽  
Polymorphonuclear Leukocytes ◽  
Total Resistance ◽  
Serum Complement ◽  
Complement Resistance ◽  
Vibrio Cholerae O139 ◽  
Relative Rarity ◽  
Human Polymorphonuclear Leukocytes

ABSTRACT Capsulated bacteria exhibit serum (complement) resistance and resistance to phagocytosis, which result in disseminated infections.Vibrio cholerae O139 strains possess a thin capsule and have been found to be partially serum resistant in a previous study. In the present study, compared to a standard capsulated Klebsiella pneumoniae strain, which showed total resistance to killing by phagocytosis, V. cholerae O139 strains were shown to be only partially resistant, with most strains showing <40% survival. These findings may explain the relative rarity of V. cholerae O139 bacteremia in cholera caused by this organism.

scholarly journals Genomic Profiling Reveals Distinct Routes To Complement Resistance in Klebsiella pneumoniae

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Francesca L. Short ◽  
Gianna Di Sario ◽  
Nathalie T. Reichmann ◽  
Colin Kleanthous ◽  
Julian Parkhill ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Underlying Mechanism ◽  
Genomic Profiling ◽  
Serum Complement ◽  
Complement Components ◽  
Content Type ◽  
Complement Resistance ◽  
Gene Sets ◽  
Capsule Retention ◽  
Selection Of

ABSTRACT The serum complement system is a first line of defense against bacterial invaders. Resistance to killing by serum enhances the capacity of Klebsiella pneumoniae to cause infection, but it is an incompletely understood virulence trait. Identifying and characterizing the factors responsible for preventing activation of, and killing by, serum complement could inform new approaches to treatment of K. pneumoniae infections. Here, we used functional genomic profiling to define the genetic basis of complement resistance in four diverse serum-resistant K. pneumoniae strains (NTUH-K2044, B5055, ATCC 43816, and RH201207), and explored their recognition by key complement components. More than 90 genes contributed to resistance in one or more strains, but only three, rfaH, lpp, and arnD, were common to all four strains. Deletion of the antiterminator rfaH, which controls the expression of capsule and O side chains, resulted in dramatic complement resistance reductions in all strains. The murein lipoprotein gene lpp promoted capsule retention through a mechanism dependent on its C-terminal lysine residue; its deletion led to modest reductions in complement resistance. Binding experiments with the complement components C3b and C5b-9 showed that the underlying mechanism of evasion varied in the four strains: B5055 and NTUH-K2044 appeared to bypass recognition by complement entirely, while ATCC 43816 and RH201207 were able to resist killing despite being associated with substantial levels of C5b-9. All rfaH and lpp mutants bound C3b and C5b-9 in large quantities. Our findings show that, even among this small selection of isolates, K. pneumoniae adopts differing mechanisms and utilizes distinct gene sets to avoid complement attack.

Activation of latent collagenase from polymorphonuclear leukocytes by cathepsin G

1979 ◽  
Vol 44 (10) ◽  
pp. 3177-3182 ◽  
Author(s):  
Mária Stančíková ◽  
Karel Trnavský
Keyword(s):  
Affinity Chromatography ◽  
Trypsin Inhibitor ◽  
Polymorphonuclear Leukocytes ◽  
Soya Bean ◽  
Cathepsin G ◽  
Sepharose Column ◽  
Bean Trypsin Inhibitor ◽  
Human Polymorphonuclear Leukocytes

Cathepsin G was isolated from human polymorphonuclear leukocytes and purified by affinity chromatography on Antilysin-Sepharose column. Purified enzyme activated later collagenase isolated from leukocytes. Activation at 36°C was maximal after 30 min incubation. Inhibitors of cathepsin G - soya-bean trypsin inhibitor, diisopropyl phosphofluoridate and Antilysin were active in inhibiting the activation of latent collagenase by cathepsin G.

scholarly journals The mechanism of leukotriene B4 export from human polymorphonuclear leukocytes.

1990 ◽  
Vol 265 (23) ◽  
pp. 13438-13441
Author(s):  
B.K. Lam ◽  
L. Gagnon ◽  
K.F. Austen ◽  
R.J. Soberman
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Leukotriene B4 ◽  
Human Polymorphonuclear Leukocytes
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