Syngeneic antitumour antibodies in rats: clearance of cell-bound antibody in vivo and in vitro

Abstract

Summary.-Hooded Lister/Cbi rats bearing the HSN.TC fibrosarcoma produced a high-titre non-complement-binding IgG antibody, and tests in vitro indicated that the syngeneic antibody was specific for this tumour. About 1-4 x 105 antibody molecules were bound per cell, a figure one eighth that for cells treated with a high-titre alloantiserum. When tumour-bearer serum was passively transferred into congenitally athymic rats bearing the HSN.TC tumour the antibody was absorbed out specifically, by comparison with control animals or athymic rats bearing an unrelated tumour that was also syngeneic in Hooded rats. The kinetics of loss of antibody from the surface of HSN.TC cells has been monitored in vitro and the antibody has been found to have an extended half-life at the cell surface (>40 h).

An ineffective monoclonal antibody-ricin A chain conjugate is converted to a tumouricidal agent in vivo by subsequent systemic administration of ricin B chain

“…We know that the epitope recognised by 11/160 antibody is a relatively stable cell surface component, and that bound antibody is not readily internalised [3]. This feature may be responsible for the fact that ricin B chain, even when administered up to 24 h after conjugate-coated tumour cells, was still able to potentiate anti-turnout effects in vivo in some circumstances.…”

Monoclonal antibodies inhibit the adhesion of mouse B 16 melanoma cells in vitro and block lung metastasis in vivo.

“…3). The procedure of syngeneic immunization has been used in analogous systems by other investigators: e.g., antibodies exclusively directed against the 60,000-dalton src gene product were obtained through immunization of BALB/c mice with Rous sarcoma-transformed BALB/c 3T3 cells (16), and monospecific antisera could be raised in rats and mice against tumor cells (15,17). Similarly, if we consider B 16 melanoma cells as tumorigenic mutants of C57BL/6 melanocytes, syngeneic immunization likely leads to antibodies against possible tumor-associated antigens.…”

Effect of host immune status on the spontaneous metastasis of cloned cell lines of the 13762NF rat mammary adenocarcinoma

“…Over the last several years there has been an accumulation of data on numerous tumour models with respect to immune parameters such as cytolysis and/or cytostasis by activated macrophages (Shin et al, 1976;Haskill et al, 1979;Mantovani et al, 1979;Reading et al, 1983), NK cells (Herberman et al, 1975;Stutman et al, 1980;Hanna, 1982), T-lymphocytes (Fogel et al, 1979;Schirrmacher et al, 1979), and humoral antibodies (Vaage, 1973;Robins & Baddwin, 1974;Dean et al, 1982). The majority of the earlier studies were conducted using highly immunogenic, chemicallyinduced tumours of rodents, and the relevance of these data to human cancer metastasis has been questioned (Alexander, 1977).…”