ABSTRACT
Five murine macrophage (M phi)-like cell lines were examined to determine their suitability for the characterization of M phi interferons (IFNs). The J774A.1, RAW 309 Cr.1, and RAW 264.7 cell lines produced 30-800 international units (IU)/10(6) cells when treated with 5-200 micrograms of bacterial lipopolysaccharide (LPS). No IFN was detected in LPS-treated P388D1 or PU5-1.8 cell cultures. All cell lines produced IFN when inoculated with Newcastle disease virus (NDV); however, only 15 IU/10(6) cells of acid stable IFN were produced in PU5-1.8 cell cultures in comparison to 4.2 X 10(3)-1.7 X 10(4) IU/10(6) cells in the other cell lines. Most of the IFN was produced within 4 h in LPS-treated cell cultures and within 12 h in NDV-infected cell cultures. All IFNs were stable at pH 2.0 and were neutralized with antiserum against mouse L cell IFN. These cell lines appear competent for use in studying the synthesis, molecular weights, and regulatory functions of M phi IFNs.
