Effect of purified 1-hydroxyphenazine pigment on active and total T rosette formation againest secondary hydatidosis

Abstract EN

Background The effect of 1-hydroxyphenazine pigment which was isolated and purified from Pseudomonas aeruginosa on specific immune response T cells inside the body of white male BALB/C mice against experimental secondary hydatidosis and the infectivity of protoscoleces was studied.

Objectives The aim of this study was to found out the effect of this phenazine pigment (1- hydroxyphenazine) on one of the specific cell-mediated reaction against experimental hyadatidosis In vivo which may affect the infectivity of hydatid cyst protoscoleces.

Methods Six mice groups were used in this research, four of them were injected with(Primary and booster doses) of four concentrations of purified 1-hydroxyphenazine pigment (25, 50 , 75 and 100 μmole/ml) isolated from Pseudomonas areuginosa and then injected with 2000 protoscoleces /ml as a challenge dose after 7 days, active and total T rosette were calculated,and after 25 weeks the infectivity of prtoscoleces were studied in relative with the numbers and diameters of hydatid cysts which formed in vitro.

Results In comparison with negative control mice groups (P.B.S.) the results showed that the higher purified concentrations (50, 75 and 100 mole/ml) of the pigment had suppressive effect on the specific immune response T cells and this effect was highly significant (P<0.01) after 6 weeks from challenge dose with protoscoleces intraperitoneally (I.P) against this pigment.

This effect reflects that the protoscoleces infectivity was increased due to suppression of T rosette formation activity of T lymphocytes while the mitogen Phytohaemagglutinin (PHA) showed a significant stimulation of the specific cellular response which decrement protoscoleces infectivity in comparison with higher pigment concentrations.

Conclusion 1-hydroxyphenazine is a toxic pigment (dose dependent) causing decrementation of T cells activity especially at higher concentrations which allow protoscoleces development and growth.