Characteristics of murine C‐type viruses. IV. The virus produced by ehrlich tumor cells and its hybrids with mouse L cells

Abstract

The iiijertious properties of viruses produced by Ehrlich tumor cells ( E ) , the A9 ,srth/irie of' mouse L cc#s ( L ) , their hj-brids ( E L , arid E L ) und high-maligtiarit suhlincs yf' the low-maligtiant hybrid line (EL,,, i W P r C investigated. The infectivity a.s.say.s wen' utitigetr induction ow JLS-V9 cells, antigenic cotiversion und focus iriductioii otr S I L wlls ( D.56 .subhe) unc/.focus .formatioti oti BAL Bl3 T3 cells. The E and L viruses, pro-rlrrrc~d by the pavetitul cells, were detected irr the JLS-V9 test but were distitiguished in S 1 L ~~~ urid BALBI3T3 cells. The L virus wus ,focus-positive, the E virus .focustiegutive ( B A L B/3T3). For utitiAwiic cotiversion, the L virus was negutive and the E virus positive ( D S 6 ) . The hybrid cell line, tested 011 sevi~rctl occasions after the hydridizatioti evetit, produced viruses with characteristics similur to both E arid L viruses, riyurcllc'ss of the complete or rerlucd chromosome numbers. The muligriunt sublines selected from the hybrid showed pryferetrtial loss of' the A9 puretit-derived biarmed chromosomes. Otie of thi.se lities produced virus (EL,,,) with infective properties similur to those of' the E virus. This suggests thut the virus produced by u particular cell line is determitred by the cell getlome. Another maligtiutit subline was .fourid to hi, ncycrtive .for productiotr of ii1fi.ctiou.s virus in all three indicator systems.The infectious properties of viruses produced in hybrid cells, resulting from the fusion of Moloney lymphomas and L cells (A9 subline) were reported previously (Fenyo et ul., 1971(Fenyo et ul., , 1973. The viruses produced by the parental ( Y .Yr and L) and hybrid cells (YL and YrL) were characterized by a panel on infectivity assays. These assays did not give concordant results when different viruses were used, allowing the infec-