The same cloned murine B lymphoma cell lines can be selectively induced to release either interleukin-1- or interleukin-2-like factor activity.

A series of cloned murine B lymphoma cell lines including WEHI-5, WEHI-231, 2PK-3 and L10A/2J have been studied previously for their ability to present soluble protein antigen in a major histocompatibility complex (MHC) restricted fashion. These B cell lines have been shown to be effective accessory cells in the in vitro stimulation of antigen-specific, MHC-restricted, continuous T cell lines; and in the in vitro stimulation of antigen-specific, MHC-restricted T-T hybridoma cell lines. Using 2PK-3 and L10A/2J as examples of this group of B cell lymphomas we demonstrate in this study that these tumor cell lines constitutively release an interleukin-1 (IL-1) like factor activity as determined by the ability of the conditioned medium from these cultures to support the synergistic stimulation of thymocyte proliferation in the presence of concanavalin A (Con A). Conversely, these same constitutive supernatants will not stimulate the proliferation of IL-2 dependent cell lines such as CTLL-2 or HT-2. Stimulation of 2PK-3 and L10A/2J by lipopolysaccharide (LPS) results in the release of increased levels of the IL-1 like factor activity. By contrast, stimulation of the same cloned 2PK-3 and L10A/2J cell lines with the polyclonal activator Staph. aureus results in the release of a soluble factor activity which functionally acts like IL-2 since conditioned medium from S. aureus stimulated 2PK-3 and L10A/2J cultures will support a CTLL proliferation response as well as stimulate thymocyte proliferation. Thus, the same cloned B cell lines can be differentially stimulated to release lymphokine activity with either IL-1 or IL-2 like functional properties.