Embryonic antigen expression in chemically induced rat hepatomas and sarcomas

Summary.-The in vitro cytotoxic immune response of spleen lymphocytes from primiparous and tumour-related mice to embryonic cells from embryos of varying age and tumour cells has been investigated. The results indicate that lymphocytes from both primiparous and tumour-related (i.e., tumour-bearing or tumour-excised) animals give a response which is greater than that from cells from control mice ("virgin cells"). Moreover, in this putative anamnestic response the immune cells detect antigenic differences in the cell populations of embryos of varying age, which are not as readily demonstrable when cytotoxicity is derived from virgin cells. As a further indication of the in vivo priming to embryo-associated antigens, the data show that the precursors of cytotoxic cells apparently undergo a blastogenic response in the presence of embryo antigen, and revert to small quiescent cells when antigen is removed, in a way entirely analogous to that described for reactivity of mixed leucocyte cultures to antigens of the major histocompatibility complex. Finally, it seems that in animals immediately after removal of embryonic antigen (and to a lesser degree in virgin or late-embryo-immune mice) there exists a suppressor cell population which inhibits an anti -embryo cytotoxic response far more than an antiallograft response.

mentioning

confidence: 99%

Response of tumour-related and normal lymphocytes to antigens on fibroblasts from embryos of varying age

Gorczynski¹

1978

“…Much attention has been given to embryonic antigens in recent years and the hypothesis that " tumour specific antigens " are re-expressed embryonic ahtigens has been derived from studies on viral and chemically induced animal tumours (Coggin, Ambrose and Anderson, 1970;Coggin et al, 1971;Baldwin, Glaves and Vose, 1972). We have therefore also looked at the blastogenic response to a cell extract of foetal ovary to see whether an oncofoetal antigen might be at least partly responsible for this blastogenic response.…”

mentioning

confidence: 99%

Tumour antigenicity in ovarian cancer

Levin¹,

McHardy²,

Curling³

et al. 1975

Summary.-The blastogenic response to a crude cell extract of ovarian cancer cells has been studied in 48 patients with ovarian cancer (9, autologous, 39 allogeneic), in 26 female controls matched for age and in 18 female patients with other types of cancer in remission from disease. The responses in ovarian cancer patients in remission and relapse were considered separately. The blastogenic responses to cell extracts of foetal ovary, foetal lung, foetal liver and normal adult ovary were also assessed in a proportion of all 3 groups.The blastogenic responses to ovarian cancer and foetal ovary cell extracts were found to be significantly greater in the ovarian cancer patients in remission than in the controls, but the responses to ovarian cancer extract were not greater in the relapse group or in patients with other cancers. As a blastogenic response to normal ovarian extract was also present in some of these patients, the data so far do not support the hypothesis of a tumour specific antigen. This tumour associated response may be occurring to determinants in foetal or adult ovarian tissue to which the patient becomes sensitized in malignant disease. The response is complex and the nature of the antigen requires further analysis.

“…This hypothesis has been advanced in studies with hamster cells transformed with SV40 and adenovirus 31 where immunization with irradiated embryo cells can produce immunity against transplanted tumour cells (Coggin, Ambrose and Anderson, 1970;Coggin et al, 1971). Since the embryonic antigens detected on chemically induced rat tumours are cross-reacting (Baldwin et al, 1972b) and the tumour rejection antigens are specific for each individual tumour, it seems unlikely that this is the case. The objective of this study has been to differentiate further between the tumour specific and embryonic antigens associated with chemically induced rat tumours.…”

mentioning

confidence: 99%

“…Preliminary evidence indicated that the embryonic antigen was present in the soluble cytoplasmic protein (cell sap) fraction of tumour homogenates (Baldwin et al, 1972c) as well as being expressed at the cell surface. In order to characterize further these embryonic antigens, their localization in tumour cells has been identified using cell fractionation studies similar to those of Baldwin and Moore (1969) (Witschi, 1956)) dissected free of extra-embryonic membranes and maintained in Waymouth's medium supplemented with 20% foetal calf serum and antibiotics.…”

mentioning

confidence: 99%

“…Membrane immunofluorescence tests.-The indirect membrane immunofluorescence test was performed on viable tumour and embryo cells in suspension as previously described (Baldwin and Barker, 1967b;Baldwin et al, 1972b). Fluorescence indices were calculated from the proportions of unstained cells exposed to test serum compared with control sera and a value of 0-30 or greater was taken to represent a significant reaction.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Differentiation Between the Embryonic and Tumour Specific Antigens on Chemically Induced Rat Tumours

Baldwin¹,

Glaves²,

Vose³

1974

Summary.-The tumour specific antigens and tumour associated embryonic antigens expressed on chemically induced rat hepatomata and sarcomata have been shown to be different by means of blocking antibody studies. Serum from multiparous female rats contained blocking antibody which protected both tumour and embryo cells from the in vitro cytotoxic effect of lymph node cells from multiparous donors. These sera did not, however, block the cytotoxicity of lymph node cells from tumour immune rats for cells of the immunizing tumour. In addition, the tumour specific rejection antigens and embryonic antigens have been shown to have dissimilar locations in tumour cells.