Propagation of Measles Virus in Human Carcinoma Cells

Because they could not regularly be reproduced, early claims of the propagation of measles virus in tissue cultures have not met with wide acceptance. However, Enders and Peebles 1 reported that an infectious agent could be isolated from the throat or blood of measles patients and readily grown in cultures of human kidney cells.

It seemed desirable to find other cells in which the virus may be propagated since human kidneys are not readily available and monkey kidney cells, although susceptible, frequently carry a latent agent which may cause lesions similar to those of measles virus. To this end, Dr. George Foley put at our disposal the KB strain of human epidermoid carcinoma cells, originally isolated by Dr. Harry Eagle 2 . These cells grow profusely in a relatively simple and well defined medium containing 10% horse serum 3 , 4 .

In tubes to which a suspension of these cells were added, confluent sheets of growth were seen after 2 or 3 days. At this time, the cells were inoculated with the fluid from the 23 rd passage in human kidney cell cultures of a strain (Edmonston) of measles virus 1 .

Daily microscopic examination of the cultures revealed on the 4th or 5 th day, 6 to 10 areas of “giant cell” or syncytial formation comparable to those described by Enders and Peebles 1 in cultures of human renal cells. By the following day, however, these “lesions” had fallen off the glass and the clear area was quickly overgrown by cells of normal appearance. Two to 3 days later, (Fig. 1), a second but larger group of giant cells appeared both in the same areas and elsewhere throughout the cell sheet.