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Investigation on extracellular slime from Pseudomonas aeruginosa as interferon inducer in mice
M Cembrzyńska-Nowak1, A Czarny
1Department of Infectious Diseases, Polish Academy of Sciences, Wroclaw.
Abstract:
The investigation concerns interferon (IFN) production in the sera and spleens of 129/Ao/Boy mice induced with Pseudomonas aeruginosa slime extract. Interferon was present in the serum as early as 2 h after i.v. and i.p. injection of the immunogenic dose of the slime - 100 micrograms/mouse. Likewise, in the spleen the same dose induced interferon production at the second hour after its administration. In the spleen interferon was synthetized longer, even up to 7 days. On the other hand, it disappeared from the serum after 24 h. In vitro investigations on interferon induction in peritoneal cells and spleen revealed that after slime extract stimulation, only non-adherent cells are capable of IFN production; while adherent cells are not. Interferon synthesis in peritoneal cells in vitro was much enchanced if for the experiments, cells isolated 2 - 4 h after i.v. administration of mice with Ps. aeruginosa slime extract, were used. Besides, the stimulatory effect of the extract on interferon production was well marked in the Newcastle virus-induced peritoneal cells. For comparison, interferon obtained after induction with slime extract in vivo (in the serum) and in vitro (in peritoneal cells) was tested for its properties. The interferons although both acidstable, displayed significant differences. IFN obtained in vitro from peritoneal cells culture appeared thermolabile and susceptible for neutralization with gamma-globulin of rabbit serum against interferon from Newcastle virus-induced L929 cells (anti-MuIFN alpha/beta). IFN from serum was thermostabile, undergoing only slight neutralization with anti-MuIFN alpha/beta globulin.
Insights
Pseudomonas aeruginosa slime extract induces interferon (IFN) in mice. This immune response differs between serum and spleen, with in vitro studies revealing specific cell types responsible for IFN production and distinct IFN properties.
Area of Science:
- Immunology
- Microbiology
Background:
- Interferon (IFN) plays a crucial role in the innate immune response against bacterial infections.
- Pseudomonas aeruginosa is an opportunistic pathogen known for its ability to modulate host immune responses.
Purpose of the Study:
- To investigate interferon production in mice following induction with Pseudomonas aeruginosa slime extract.
- To characterize the kinetics and cellular sources of interferon induction in vivo and in vitro.
- To compare the properties of interferon produced in vivo versus in vitro.
Main Methods:
- Induction of interferon in 129/Ao/Boy mice using Pseudomonas aeruginosa slime extract via intravenous (i.v.) and intraperitoneal (i.p.) injection.
- Quantification of interferon levels in serum and spleen at various time points post-induction.
- In vitro interferon induction assays using peritoneal cells and spleen cells, differentiating between adherent and non-adherent cell populations.
- Characterization of interferon properties, including thermostability and susceptibility to neutralization.
Main Results:
- Interferon was detected in mouse serum and spleen as early as 2 hours after slime extract administration.
- Serum interferon levels decreased significantly within 24 hours, while splenic interferon persisted for up to 7 days.
- In vitro, only non-adherent peritoneal cells produced interferon upon stimulation with the slime extract.
- Interferon synthesized in vitro exhibited thermolabile properties and was neutralized by anti-IFN alpha/beta globulin, unlike the thermostable serum interferon.
Conclusions:
- Pseudomonas aeruginosa slime extract is a potent inducer of interferon in mice, with distinct temporal profiles in serum and spleen.
- Non-adherent peritoneal cells are the primary source of interferon production in response to the slime extract in vitro.
- Interferon produced in vivo and in vitro demonstrates differing physicochemical properties, suggesting distinct molecular forms or associated factors.