THE JOURNAL OF INFECTIOUS DISEASES. VOL. 136, NO.3. SEPTEMBER 1977
© 1977 by the University of Chicago. All rights reserved.
Murine Cy~omegalovirus Infection of Epithelial Cells in Mouse Tracheal Ring Organ Culture Rauno A. Mantyjarvi,* MaryJane K. Albert M. Collier, Shih-chin Hu, and Joseph S. Pagano
From the Cancer Research Center and the Departments of Pediatrics, Bacteriology and Immunology, and Medicine, University of North Carolina, Chapel Hill, North Carolina
Selgrad~,t
in immunosuppressed mice, with recovery of virus from lungs that show characteristic interstitial changes [3]., Viral particles in lung tissue of mice infected with CMV were present only in monocytes, whereas in human CMV pneumonia inclusion bodies [1, 4] and virus particles [5] were found in epithelial cells. We have found that a productive infection of epithelial cells with murine CMV can be induced in mouse tracheal organ culture and that the progress of infection may be followed conveniently in this system.
Interstitial pneumonia is one of a variety of clinical manifestations caused by postnatal infection with cytomegalovirus (CMV). In transplantation recipients, CMV pneumonia, the pathogenesis of which is not understood, is a serious and sometimes fatal complication, particularly in those receiving bone marrow transplants [1]. Experimental models have been developed to study this problem. Murine CMV has many biologic and virologic similarities to human CMV. When murine CMV is introduced parenterally into susceptible mice, the main target organs of the virus are liver, spleen, pancreas, and salivary glands [2]. CMV pneumonia can be induced
Materials and Methods
Cell cultures, virus propagation, and assay. Mouse embryo cell cultures (MECC) were prepared and maintained as described previously [6]. Pools of cell culture-passaged (attenuated) murine CMV (Smith strain) were prepared by infecting secondary MECC and then clarifying the culture fluid by low-speed centrifugati,on [2]. Virus was passaged 14 times in MECC. Infectivity titers were determined by plaque assay in MECC [2]. Organ cultures and experimental design. Tracheal rings were prepared from female Swiss mice [7]. Five to six rings were placed in a plastic petri dish (35 mm in diameter; Falcon Plastics, Oxnard, Calif.) containing 1.2 ml of minimal essential medium supplemented with 1% fetal calf serum and were kept at 37 C in a humidified atmosphere containing 5% CO 2 , Medium was changed twice weekly.
Received for publication December 24, 1976, and in revised form March 22, 1977. This study was supported in part by the Sigrid Juselius Foundation, the Medical Research Council, Academy of Finland; by grant no. 5-P30-CAI6086-02 from the National Institutes of Health; by Specialized Center of Research grant no. HL 19171-01 from the National Heart, Lung, and Blood Institute; by fellowship no. I :1'32 AJ05087·01 awarded to Dr. Selgrade by the U.S. Public Health Service; and by grant no. 1975-76-A-3 from the North Carolina Heart Associ
© 1977 by the University of Chicago. All rights reserved.
Murine Cy~omegalovirus Infection of Epithelial Cells in Mouse Tracheal Ring Organ Culture Rauno A. Mantyjarvi,* MaryJane K. Albert M. Collier, Shih-chin Hu, and Joseph S. Pagano
From the Cancer Research Center and the Departments of Pediatrics, Bacteriology and Immunology, and Medicine, University of North Carolina, Chapel Hill, North Carolina
Selgrad~,t
in immunosuppressed mice, with recovery of virus from lungs that show characteristic interstitial changes [3]., Viral particles in lung tissue of mice infected with CMV were present only in monocytes, whereas in human CMV pneumonia inclusion bodies [1, 4] and virus particles [5] were found in epithelial cells. We have found that a productive infection of epithelial cells with murine CMV can be induced in mouse tracheal organ culture and that the progress of infection may be followed conveniently in this system.
Interstitial pneumonia is one of a variety of clinical manifestations caused by postnatal infection with cytomegalovirus (CMV). In transplantation recipients, CMV pneumonia, the pathogenesis of which is not understood, is a serious and sometimes fatal complication, particularly in those receiving bone marrow transplants [1]. Experimental models have been developed to study this problem. Murine CMV has many biologic and virologic similarities to human CMV. When murine CMV is introduced parenterally into susceptible mice, the main target organs of the virus are liver, spleen, pancreas, and salivary glands [2]. CMV pneumonia can be induced
Materials and Methods
Cell cultures, virus propagation, and assay. Mouse embryo cell cultures (MECC) were prepared and maintained as described previously [6]. Pools of cell culture-passaged (attenuated) murine CMV (Smith strain) were prepared by infecting secondary MECC and then clarifying the culture fluid by low-speed centrifugati,on [2]. Virus was passaged 14 times in MECC. Infectivity titers were determined by plaque assay in MECC [2]. Organ cultures and experimental design. Tracheal rings were prepared from female Swiss mice [7]. Five to six rings were placed in a plastic petri dish (35 mm in diameter; Falcon Plastics, Oxnard, Calif.) containing 1.2 ml of minimal essential medium supplemented with 1% fetal calf serum and were kept at 37 C in a humidified atmosphere containing 5% CO 2 , Medium was changed twice weekly.
Received for publication December 24, 1976, and in revised form March 22, 1977. This study was supported in part by the Sigrid Juselius Foundation, the Medical Research Council, Academy of Finland; by grant no. 5-P30-CAI6086-02 from the National Institutes of Health; by Specialized Center of Research grant no. HL 19171-01 from the National Heart, Lung, and Blood Institute; by fellowship no. I :1'32 AJ05087·01 awarded to Dr. Selgrade by the U.S. Public Health Service; and by grant no. 1975-76-A-3 from the North Carolina Heart Associ
