Chick Embryo Lethal Orphan Virus Research Articles

Ependymomas induced in hamsters inoculated with an avian adenovirus (CELO).

THE chicken–embryo–lethal–orphan (CELO) virus, an endogenous adenovirus of chicken eggs and the aetiologic agent of an inapparent infection in chickens1–3, is oncogenic when inoculated subcutaneously in hamsters4,5. Although a number of other viruses have also been found to be tumorigenic, only the highly oncogenic simian virus 40 (SV40) and the adeno 7–SV40 hybrid have induced ependymomas in laboratory animals6–8. Because embryonated eggs are used in producing certain vaccines, the work described here was undertaken to determine the effect of inoculating CELO virus into the brains of newborn golden Syrian hamsters.

Chick embryo lethal orphan (CELO) virus as a possible contaminant of egg-grown virus vaccines.

SUMMARYThe inactivation kinetics of CELO virus were studied in the presence of 1/4000 formaldehyde. Inactivation of the virus by formaldehyde at 4° C. was not complete after 14 days incubation. Formaldehyde inactivation at 36° C., however, was rapid and no virus was detected after 24 hr. incubation.Neutralizing antibody to CELO virus was detected in 20–88% of sera tested from five flocks of hens. This suggested dissemination of the virus in England and Scotland. However, no CELO virus neutralizing antibody at a serum dilution of 1/8 was detected in 142 normal human sera or in 229 sera from persons who had been immunized with egg grown, inactivated influenza virus vaccine.We would like to thank Professor C. H. Stuart-Harris and Drs J. E. Wilson, D. A. Martin and D. Breeze for their help and their criticisms of the manuscript.Dr G. C. Schild kindly supplied a number of the human sera used in the study. The study was financed in part by the National Fund for Research in Poliomyelitis and other Crippling Diseases and by the British Empire Cancer Campaign.

Immunological relationships of some oncogenic DNA viruses. II. Primary tumour inhibition studies.

Newborn hamsters were inoculated with SV40 virus to produce subcutaneous tumours and during the subsequent tumour incubation period they were immunized with homologous and heterologous viruses. The incidence of tumours in animals given only the single tumour producing dose of SV40 virus was 50%. In the group of hamsters subsequently immunized with further doses of SV40 virus the tumour incidence was reduced to 4.8%. The incidence of SV40 tumours was not reduced significantly when hamsters were immunized with adenovirus types 12 or 31, or human wart virus. However, immunization with chick embryo lethal orphan (CELO) virus reduced the incidence of SV40 induced tumours to 5.6%. No serological relationship between SV40 virus, CELO virus and adenovirus type 12 could be demonstrated by specific cross-neutralization tests.

Specific tumour antigen induced by chick embryo lethal orphan (CELO) virus.

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Growth of Chicken-Embryo-Lethal-Orphan (CELO) Virus in Chicken Embryo Neuroglial and Chicken Embryo Fibroblastic Cell Cultures

The chicken-embryo-lethal-orphan (CELO) virus is an avian adenovirus that is frequently endogenous in chicken eggs. It was first reported by Yates et al. (6,7), and characterized by Yates in 1960 (8). To date the only successful means of propagating this virus in vitro has been in chicken embryo kidney cell cultures (1). This report describes the growth of CELO virus in both chicken embryo neuroglial and chicken embryo fibroblastic monolayer cell cultures.

A Serological Investigation to Determine Respiratory Infections of Poultry in India

A plurality of agents of varying pathogenic potentials are involved in respiratory infections of poultry (4). Antibodies to pleuropneumonia-like organisms (PPLO) are known to be widespread in India (1,3,7,10,11). Serological evidence for the presence of antibodies to infectious bronchitis (IB) and infectious laryngotracheitis (ILT) has been presented on the basis of a report received from Dr. Bankowski of the University of California, to whom were forwarded some sera for diagnosis (12). Antibodies to Chick Embryo Lethal Orphan (CELO) virus have not yet been reported from India. Except for the surveys to assess the presence of Mycoplasma gallisepticum, no comprehensive serological investigations of respiratory infections have been reported. This paper presents results of a simplified qualitative procedure utilizing a minimum number of eggs per serum for detection of antbodies against 3 viruses (IB, ILT, and CELO) besides M. gallisepticum.

Induction of Tumors in Hamsters with an Avian Adenovirus (CELO)

When newborn hamsters were inoculated subcutaneously with chicken-embryo lethal orphan virus, tumnors developed at the site of inoculation in 23 out of 69 hamsters within 88 to 195 days of inoculation. These tutlnors and tissue cultures, prepared from a primary tumor, were transplantable to newborn and weanling hamsters. The primary tumnors and tissue cultures of a primary tumor were free of demnonstrable infectious virus. The virus is the first "nonhuman" adenovirus found to induce tumors in hamsters.

Evaluation of the Immunity Response to Infectious Bronchitis Virus

Much new knowledge has been gained in the past decade on strain differences in infectious bronchitis virus (IBV). Before 1956 it was assumed that there was only one antigenic type of IBV. In 1956, Jungherr et al. (6) reported an isolate from Connecticut (Conn.) that differed antigenically from an isolate obtained from Van Roekel of Amherst, Massachusetts, designated the Massachusetts (Mass.) type. Hofstad (4) later demonstrated two additional isolates, from Iowa, identified as numbers 97 and 609, that were serologically different from the Mass. and Conn. types. Two additional IBV isolates that manifest a low incidence of renal tropism in chickens, identified as Holte and Gray, have been reported by Winterfield and Hitchner (10). Yates and Fry (11) isolated an agent that produced lesions in embryos resembling IBV, which they have termed chicken embryo lethal orphan (CELO) virus. DuBose and Grumbles (2) studied the characteristics of CELO and quail bronchitis virus (QBV) and concluded they were identical agents. Previously, in 1950, Olson (7) had reported on an infectious bronchitis (IB) of quail, at which time he pointed out the similarities of the pattern of virus growth in embryos to that of IB of chickens. He suggested that there may be types of IBV, as in human influenza, in which little or no cross immunity exists. Data presented here substantiate and extend the findings of former workers and point out the need for a systematic approach to the classification of IBV.

ELECTRON MICROSCOPIC STRUCTURE OF CHICKEN EMBRYO LETHAL ORPHAN VIRUS.

SummaryThe chicken embryo lethal orphan (CELO) virus is 73 mμ in diameter and the distance between the centers of adjacent capsomeres is 76 A. The virus is a regular icosahedron (cubic symmetry) having 252 capsomeres and without an envelope. The CELO virus could be classified in the adenovirus group.

The Relationship between Quail Bronchitis Virus and Chicken Embryo Lethal Orphan Virus

The Relationship between Quail Bronchitis Virus and Chicken Embryo Lethal Orphan Virus