The role of fetal calf serum in the primary immune response in vitro.

Abstract

The mode of action of 2-mercaptoethanol (2-ME) on the primary immune response in vitro was investigated. Fetal calf serum (FCS) was preincubated with 2-ME and lyophilized to remove free 2-ME. This 2-ME-treated FCS was able to substitute the function of adherent cells in the primary immune response against sheep red blood cells (SRBC) in vitro; Fractionation of 2-tme-treated FCS on a Sephadex G-100 column showed that 2-ME acted on a high molecular serum component which after activation, could substitute for macrophages. In order to obtain a humoral immune response against SRBC in vitro, spleen cells require selected FCS. These "good" sera could be distinguished from "deficient" sera by their higher content of this 2-ME-activated factor. The height of the in vitro immune response to SRBC was dependent on the amount of activated factor added to the culture medium. FCS normally required in the culture medium could be completely replaced by the factor-containing fraction without deleterious effect on the culture medium. The factor should be added to the spleen cells during the first 24 h of culture and remain there for 72 h in order to obtain an optimal immune response. The factor could be partially absorbed by spleen cells but not by SRBC. The relationship between macrophage, 2-ME, and FCS in eliciting an in vitro primary immune response is discussed.

Augmentation of in Vitro Antibody Response by Disulfide Compounds I. Comparison between Intermolecular and Intramolecular Disulfides

“…Broome and Jeng have demon strated that a variety of thiol and disulfide compounds could stimulate the in vitro growth of L1210, a murine lymphoma (2). Several reports have appeared for explaining the mechanism of action of 2-ME (3,4). Its mode of action, however, has remained unclear for a long period, particularly at the molecular level.…”

Augmentation of the Antibody Response by Lipoic Acid in Mice II. Restoration of the Antibody Response in Immunosuppressed Mice

“…It has been reported that various thiol and disulfide compounds are able to augment the in vitro antibody response (1)(2)(3)(4)(5). In the preceding paper (6), we demonstrated that lipoic acid (Lip), a naturally occurring disulfide compound showed augmenting effects on in vitro antibody responses in murine lymphocytes.…”

The Use of β-Cyclodextrin-Containing Culture Medium for In Vitro Evaluation of Immunomodulating Agents

“…RPMI-1640 medium containing 10% fetal calf serum (FCS), that is tentatively referred to as 1 OF medium in the present paper, has been usually used for eliciting the in vitro antibody response in murine lymphocytes (1). However, it has been frequently pointed out that the magnitude of the antibody response varied drastically depending on the lot of FCS added to the culture medium (1,2).…”

“…However, it has been frequently pointed out that the magnitude of the antibody response varied drastically depending on the lot of FCS added to the culture medium (1,2). If one can devise some means to reduce the FCS requirement or to utilize any lot of FCS, such a procedure would be useful in various experi mental systems.…”