Studies on the Fc receptor bearing cells in a transplanted methylcholanthrene induced mouse fibrosarcoma

Abstract

Summary.-The presence of Fc receptors on the surface of cell suspensions obtained from a transplanted isogeneic methylcholanthrene induced murine fibrosarcoma has been investigated by determining the capacity of such cells to form rosettes with antibody coated SRBC.These studies indicate that a large percentage of cells in the tumour had Fc receptors on their surface. The proportion of such cells was increased by reducing the number of cells transplanted, by administering cyclophosphamide to the host, and on occasions by the i.p. injection of C. parvum. It was largely unaffected by the route of tumour cell transplantation or by T cell depletion of the host before transplantation but appeared to decline in older (i.e. larger) tumours. Both phagocytic and non-phagocytic cells had Fc receptors on their surface. The phagocytic population appeared to be affected most by procedures which altered the overall percentage of Fc receptor bearing cells. The Fc receptor bearing tumour cells were separated from those devoid of Fc receptors on the basis of their adherent properties. Upon transplantation to isogeneic hosts both populations gave rise to tumours containing a high percentage of Fc receptor bearing cells. These studies suggest that many of the Fc receptor bearing cells in our tumour are probably infiltrating cells of host origin. Their significance in relation to tumour growth remains to be established. DETAILED studies during the past few years have convincingly demonstrated that normal and malignant lymphoid and reticuloendothelial cells may have on their surface receptors for antigen/antibody complexes and aggregated JgG, the so-called Fc receptors (reviewed by Kerbel and Davies, 1974). A number of observations also indicate that a significant proportion of the cells in certain nonlymphoreticular tumours may also possess Fc receptors (Milgrom et al., 1968;Cohen, Gurner and Coombs, 1971;Tonder, Morse and Humphrey, 1974;Kerbel and Davies, 1974). These Fc receptors have been demonstrated by both cryostat haemadsorption techniques (Milgrom et al., 1968;Tonder et al., 1974) and by conventional rosetting procedures with suspensions of tumour cells and antibody coated sheep erythrocytes (Cohen et al., 1971;Kerbel and Davies, 1974). The tumours studied included a variety of human adenocarcinomata and epidermoid carcinomata (Tonder et al., 1974), tumours of murine connective and epithelial tissue (Kerbel and Davies, 1974) and a transmissible venereal tumour in the dog (Cohen et al., 1971 (MacLennan, 1972). Furthermore, if the major proportion of Fc receptor bearing cells in tumours is macrophages, then this would provide an additional method for monitoring the macrophage content of tumours and establishing their importance in relationship to tumour growth.In view of these possibilities, we have investigated the Fc receptor bearing cell content of a transplanted syngeneic, methyleholanthrene induced mouse fibrosarcoma. We have been particularly MATERIALS AND METHODSMice. The experiments were performed in inbred CBA mice ...

Fc receptor-bearing and phagocytic cells in syngeneic tumours of C. parvum- and carrageenan-treated mice

“…The decline in the proportion of Fcreceptor-bearing cells with increased tumour size observed in the present study is consistent with work on other tumours by Szymaniec & James (1976) and Moore & Moore (1977). Fc-receptor-bearing cells within tumours may constitute a heterogeneous population, since a variety of cells, other than macrophages, including B or T lymphocytes, neutrophils, eosinophils and mast cells may display this characteristic (see Korn et al, 1978).…”

“…However, Szymaniec & James (1976) found that C. parvum occasionally had an appreciable antitumour effect without increasing the proportion of Fcreceptor-positive cells within the tumour. In contrast, Eccles & Alexander (1974a) showed that BCG induced a small decrease in metastasis which was associated with a slight increase in tumour macrophages.…”

Further studies on antitumour responses induced by short-term pretreatment with syngeneic tumour cells

“…For example, in the light of previous observations from our laboratory on the CCH 1. tumour used in these studies (Szymaniec and James, 1976) it is conceivable that freshly excised tumour-cell suspension contained suppressor cells (either T cells or macrophages) which interfered with the developmeent of prompt and effective anti-tumour immunity. In this context it could be argued that the superior lung-colonizing properties of freshly excised tumour, over their cultured counterparts (see Fig.…”

Immunological and biochemical characteristics of acid citrate eluates from tumour cells: a major non-immunoglobulin component

“…For example, a 25K component has been found in eluates from some mechanically prepared liver-cell suspensions (Fig. 5) (Szymaniec & James, 1976). Nevertheless, there was the possibility that the Fc receptors were present but only became exposed by acid citrate treatment.…”