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Induction of interferon and erythropoietic differentiation in cells transformed by Friend virus
Abstract:
Two lines of Friend virus (FV)-transformed mouse spleen cells have been analyzed in respect to their interferon production capacity: neither F4 cells, which liberate infectious FV when kept under tissue culture conditions, nor the thymidine kinase-deficient B8 cells, which do not produce significant amounts of FV, release detectable amounts of autogenous interferon into cell supernatants. However, interferon is produced in these cells in amounts comparable to that in L-929 cells when interferon induction is initiated with UV-inactivated Newcastle disease virus. Conversely poly(I)-poly(C), a potent interferon inducer in L-929 cells, proved ineffective in this capacity in F4 or B8 cells. When erythropoietic differentiation is induced in these cells by dimethyl sulfoxide, no autogenous interferon production occurs, but with NDV-induction a four- to fivefode increase of interferon production is observed. A similar elevation of interferon production is achieved during 5-bromodeoxyuridine stimulation of differentiation in the thymidine kinase-deficient B8 cells. The refractiveness against poly(I)-poly(C) displayed in unstimulated cells is not overcome at any stage of differentiation, indicating major differences of Newcastle disease virus and poly(I)-poly(C) induction mechanisms.
Insights
Friend virus-transformed mouse spleen cells do not produce interferon spontaneously. However, they produce interferon upon Newcastle disease virus induction, but not with poly(I):poly(C), revealing distinct induction pathways.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- Friend virus (FV)-transformed mouse spleen cells (F4 and B8) were studied for interferon production.
- Understanding interferon responses in FV-transformed cells is crucial for viral pathogenesis research.
Purpose of the Study:
- To investigate the interferon production capacity of FV-transformed mouse spleen cells.
- To compare the efficacy of different interferon inducers (Newcastle disease virus and poly(I):poly(C)) in these cells.
- To determine the effect of induced differentiation on interferon production.
Main Methods:
- Analysis of interferon production in F4 and B8 cells under basal conditions.
- Interferon induction using UV-inactivated Newcastle disease virus (NDV) and poly(I):poly(C).
- Induction of erythropoietic differentiation using dimethyl sulfoxide (DMSO) and 5-bromodeoxyuridine (BrdU).
Main Results:
- Neither F4 nor B8 cells produced detectable autogenous interferon.
- UV-inactivated NDV effectively induced interferon production in F4 and B8 cells.
- Poly(I):poly(C) failed to induce interferon in F4 and B8 cells, unlike in L-929 cells.
- Induced differentiation (DMSO or BrdU) did not trigger autogenous interferon production but enhanced NDV-induced interferon levels.
- Refractoriness to poly(I):poly(C) persisted throughout differentiation.
Conclusions:
- FV-transformed mouse spleen cells exhibit differential responses to interferon inducers.
- NDV and poly(I):poly(C) likely utilize distinct signaling pathways for interferon induction in these cells.
- Cellular differentiation modulates interferon production capacity but does not overcome the poly(I):poly(C) unresponsiveness.