Effect of normal mouse serum on mouse lymphocyte transformation in vitro

Abstract

Mouse spleen cells were cultured in the presence or absence of one of the following mitogens: phytohemagglutinin (PHA), concanavalin A, allogeneic spleen cells or bacterial lipopolysaccharide. The addition of normal mouse serum (NMS) to the cultures usually depressed mitogen-induced lymphocyte transformation as measured by DNA, RNA o r protein synthesis, whether calculated as gross o r net synthesis. The degree of depression was increased as the concentration of NMS serum increased. DNA and RNA synthesis in unstimulated cultures were also usually depressed by NMS. NMS added 24 hours or more after the start of cultures with PHA o r allogeneic lymphocytes was less depressive than serum present from the start and in some cases, actually increased DNA synthesis. The presence of NMS in cultures containing supra-optimal doses of concanavalin A could also increase DNA synthesis. Cells incubated with NMS for 2 4 hours survived as well as cells incubated without NMS, but subsequently responded less well t o PHA. Cells passed through a column of glass wool had a lower baseline DNA synthesis, which was not inhibited by NMS; they responded less well to mitogens and this response was further depressed by NMS.It is suggested that NMS contains a factor which damps the proliferation of mouse T and B cells, without exerting an overt cytotoxic effect, and that it acts directly on lymphocytes.

Regulation of Lymphocyte Activation by Serum Factors

“…data]. Different opinions concerning the effect of NMS on the mixed lymphocyte reaction have been published earlier [13,16]. However, these authors mainly used different serum concentrations, and if these discrepancies are taken into ac count, the results could be compatible with each other.…”

“…No conclusive evidence for the effect was obtained [3,4], The result of addition of autologous mouse serum to lymphocytes stimulated by polyclonal T cell activators, such as concanavalin A, as well as to poly clonal B cell activators (PBA), as measured by 3H-thymidine incorporation, has also been studied. It has been shown that concanavalin A, phytohemagglutinin and lipo polysaccharide (LPS)-induced increase in DNA synthesis is diminished, when lympho cytes are cultured with NMS [13]. It has also been reported that the polyclonal acti vation of plaque-forming cells (PFC) by fe tal calf serum is inhibited by syngeneic mouse serum [5].…”

“…It has been shown that supplementation with autolo gous or homologous normal mouse serum (NMS) can enhance the mixed lymphocyte reaction (MLC) [16]. However, other inves tigators have shown that autologous serum can inhibit a primary MLC [13]. The influ ence of NMS on primary immune responses to sheep red blood cells has also been stud ied.…”

In vitro anti-tumour activity of tumour necrosis serum

“…The background activity of NMS can partly be ascribed to the presence of minor amounts of TNF (Shah, Green & Moore, 1978;Green, Chiasson & Shah, 1979) and partly to another factor shown to inhibit DNA synthesis by mouse lymphocytes (Nelson & Shneider, 1974;Smith & HammarstrOm, 1979). This factor shares some physicochemical characteristics with TNF such as its nondialysable glycoprotein nature, its heat-stability (30 min, 56°C) and its electrophoretic mobility as an a-globulin (Nelson & Shneider, 1974;Green, Dobrjansky, Carswell, Kassel, Old, Fiore & Schwartz, 1976). TNF, however, has another elution pattern on Sephadex G20 o (Green et al, 1976) and unlike the other inhibitory factor (Nelson, 1972), cannot be demonstrated nor induced in serum of nude mice (Hoffmann, Oettgen, Old, Mittler & Hammerling, 1978).…”

Effect of Treatment With Azathioprine on the Responses of Rat Lymphocytes to Phytohaemagglutinin

“…Norway). The discs were counted with PPO-PO POP-toluene scintillant as described elsewhere (Nelson and Shneider, 1974). The results are shown as arithmetical mean counts per minute (c.p.m.)…”