Antibody to feline oncornavirus‐associated cell membrane antigen in neonatal cats

Abstract

Antibodies to a feline oncornavirus‐associated cell membrane antigen have been found in newborn kittens whose mothers had previously nursed litters of kittens injected with feline leukemia virus (FeLV). These antibodies, which were apparently obtained passively from the mother, seem to protect the kittens from the development of progressive tumors following the injection of various amounts of feline sarcoma virus (FSV). That these mothers were apparently able to passively transmit immunity suggests that they became infected with FeLV in a horizontal manner while nursing previous litters and resisted the development of progressive tumors, but mounted an immune response which resulted in the production of humoral antibody. It also suggests that some degree of cross‐protection exists in vivo between the feline leukemia and sarcoma viruses used in this study.

Prevention of Murine Sarcoma Virus Oncogenesis in Offspring of Immunized Female Mice

“…This last possibility seems most unlikely, however, since passive transmission of maternal immunity in the mouse takes place mainly after birth through colostrum and milk (Brambell, 1970 A reduced number of tumours was also observed in 3 out of 14 MSV-M-injected litters whose mothers had been previously exposed to the virus while nursing infected offspring. A similar observation has been made by Essex et al (1971), who found that kittens born to and nursed by mothers that had previously nursed litters injected with feline leukaemia virus were protected from development of tumours following injection of feline sarcoma virus. These findings suggest that horizontal transmission of leukaemia and sarcoma viruses does occur, albeit rarely, and that it may have some practical significance under natural conditions as well (Brodey et al, 1970 (Hartley and Rowe, 1966;Chuat et al, 1969).…”

Feline oncornavirus-associated cell-membrane antigen (FOCMA): distinction between FOCMA and the major virion glycoprotein.

“…This occurs both following laboratory inoculation with concentrated live virus preparations (6-10) and after horizontal contact exposure to virus under laboratory (6,9,11,12) and field conditions (13)(14)(15). The levels of FOCMA antibody detected in sera of virus-exposed cats have been shown to be predictive of tumor occurrence and growth.…”

RNA-tumour-virus genes and transforming genes: patterns of transmission

“…They also make antibodies to a new virus-induced cell-membrane antigen (or antigens) called FOCMA (feline oncornavirus cell membrane antigen) (Essex et al, 1971a, b (Essex et al, 1975a, b;1976). The FOCMA antigen that is present in the cell membrane does not appear to be identical to any of the known viral structural proteins, at least in the form that we know them in the virus particle.…”