Immunofluorescent studies of human cell cultures and chick embryos inoculated with the ameboid cell-"lipovirus" complex.

Tissue culture cells of human origin (HeLa, Lich, and AV(3)) were inoculated with the AL complex. By immunofluorescent staining, AL complex antigen was detectable in the cytoplasm of infected cells as punctate fluorescent granules during the early stage and as homogeneous fluorescence during the late stage of infection. By combining fluorescence and phase-contrast microscopy, many infected cells with cytoplasmic AL complex antigen were shown to have a normal nuclear morphology indistinguishable from uninfected cells. Initiation of AL complex infection was interpreted as occurring by transfer of transmissible factor(s) from cell to cell by contact and mutiplication of such factor(s) therein. Chick embryos were susceptible to AL complex infection following allantoic or amniotic inoculations. Antigen and infectious AL complex were demonstrable in the liver, brain, intestines, lungs, and embryonic membranes. Further investigations on AL complex and its relation to human disease are suggested.