The indentification of foetal antigens in human bone marrow cells

Immunochemical delineation of an oncofetal antigen on normal and simian virus 40-transformed human fetal melanocytes

Human melanoma cells of uveal origin shed 94,000- and 240,000-dalton glycoproteins in common with most melanoma cell lines of dermal origin. Normal human melanocytes derived from fetal uvea shed a 90,000-dalton glycoprotein that was found to be immunologically identical with the 94,000-dalton glycoprotein of melanoma cells. Expression of this 90,000-dalton molecule was confined to fetal cells of ectodermal origin. After simian virus 40 (SV40) transformation of human fetal melanocytes, there was an apparent increase in molecular size of this component to 94,000 daltons. In contrast, the 240,000-dalton glycoprotein was not synthesized or shed by uninfected or SV40-transformed fetal melanocytes. These data suggest that the 94,000-dalton glycoprotein is an oncofetal antigen of ectodermal origin.

Ductular carcinoma of the breast: serum antibodies to tumor-associated antigens

Serum antibodies to tumor-associated antigens of breast carcinoma have been studied by indirect immunofluorescence in 109 patients with breast carcinoma and 125 controls, including age/sex matched normal individuals, patients with nonmalignant disease, and patients with malignant disease other than breast cancer. We report here that sera of a large proportion of patients with ductular carcinoma of the breast have antibodies to cell surface and/or intracellular antigens of autologous tumor cells and include evidence that the antigens are absent from a considerable range of normal and other types of malignant tissues. In addition to testing of control sera, specificity of the reacting antibodies was investigated further by testing of sera with normal breast tissue and the absorption of sera from breast cancer patients with various normal tissues and cancer cells. The significance of the findings in breast cancer is discussed.

The role of the lymphocyte in haemopoiesis

According to current dogma, circulating blood cells are all derived from the same progenitor, which therefore must be both pluripotent and capable of prolific self-replication. In the irradiated mouse, such haemopoietic stem cells (HSC) give rise to splenic colonies, and thus are designated as CFU-S (colony forming units-spleen). Definitive identification of a similar entity in man so far has proved elusive. However, primitive unipotent cells, committed to development along a single pathway, can be detected in human blood-forming tissues under appropriate culture conditions. Operationally defined as CFU-E (erythrocyte), CFU-GM (granulocyte/macrophage) etc., the ontogenetic relationships of these cells to each other and to the HSC have been the objects of exhaustive study. A population of lymphocytes, classed as "null" cells, do not exhibit the surface membrane markers which characterize commitment to differentiation in the thymus-dependent (T-cell) or bursa- equivalent (B cell) lineages. Accumulating evidence points to the null lymphocyte as a potential precursor of haemopoietic tissue. In bone marrow, the activity of terminal deoxynucleotidyl transferase (TdT) is concentrated in null cells, but the relevance of this unique enzyme to lymphocytic differentiation remains uncertain. Nevertheless, it appears that the functional heterogeneity, expressed within the family of lymphocytes, extends to haemopoiesis. The roles of various lymphocyte populations, in the generation and functional control of blood-forming tissue, are examined in this review.

Long-term organ culture of human skin: an ultrastructural and immunochemical study

Human skin grown in tissue culture medium for periods of up to 18 wk undergoes characteristic morphological changes. After an initial period of degeneration, new foci of epidermal cells arise at the dermo-epidermal junction and by rapid proliferation these cells spread out to form a complete second epidermal layer beneath the degenerating original strata. Stratification occurs in this new epidermis with incomplete keratinisation. The individual keratinocytes show ultrastructural similarities with fetal cells. There is a loss of complexity of the cytoplasm typified by a marked reduction in the numbers of keratin filaments and a decrease in the numbers of desmosomal contact areas. In addition, the formation of cilia and accumulation of glycogen in the cell cytoplasm are characteristic. The cytoplasm of the basal cells contains numerous polyribosomes and there is evidence of synthetic activity as illustrated by the proliferation of rough-surfaced endoplasmic reticulum and Golgi complex. Fluorescent and EM immunocytochemical staining with an anti-fetal antiserum demonstrates the development of fetal substances on the surface of cells during the regeneration stage occurring in the cultured skins. The significance of these observations concerning transplantability of cultured tissues is discussed.

Foetal-associated material: its expression in long-term cultured human skin

Using immunofluorescence and electron microscopy, we have demonstrated the presence of "foetal substances" (antigens) in skin kept in tissue culture medium for periods of time ranging from 9 days-18 weeks. This is a specific reaction demonstrated with an anti-human foetal serum raised in New Zealand white rabbits. It is suggested that the expression of foetal substances by cells in the skin under these abnormal conditions might lead to the masking or modification of the normal histo-compatible antigens, enabling such skins to survive transplantation without rejection.