Lymphokines and interleukins emerge from the primeval soup

Preparation and application of polyclonal antibodies to recombinant human interleukin-1 alpha and interleukin-1 beta

We report the preparation and application of polyclonal antisera to the analysis and quantitation of human interleukin-1 alpha (IL-1 alpha) and human interleukin-1 beta (IL-1 beta). The anti IL-1 alpha antibodies specifically react with the alpha form of IL-1 and do not cross react (less than 0.1%) with the beta form of IL-1 and vice versa. Data reported here demonstrate that detection of human IL-1 alpha or beta by a radioimmunoassay technique is sensitive enough to measure picogram levels of these lymphokines. The practical application of using these highly specific antisera for radioimmunoassays was established by measuring exogenously added IL-1 alpha or IL-1 beta to human plasma. Potential benefits of these reagents and the radioimmunoassay procedures described herein are discussed in relation to the biological assays which cannot distinguish between human IL-1 alpha and human IL-1 beta.

Regulation of human gamma-interferon and beta-interferon gene expression in PHA-activated lymphocytes

Two interferon (IFN) messengers were synthesized in phytohemagglutinin (PHA)-activated lymphocytes: IFN-gamma mRNA and a messenger hybridizing with the IFN-beta 2 probe. They were induced rapidly and declined at a stage when overall RNA was still efficiently transcribed. The IFN-beta 2 mRNA (15S) present in the lymphocytes was slightly different from its fibroblastic counterpart (14S). The kinetics of the accumulation and decay of both lymphocyte IFN messengers differed when assessed by hybridization with the two IFN probes, IFN-gamma mRNA was not detected before mitogenic activation and accumulated for up to 15 h postactivation, while IFN-beta 2 mRNA accumulated even in the absence of PHA activation for up to 5 h, even though the activation raised the IFN-beta 2 mRNA level at 5 h. The disappearance of IFN messengers was prevented when cycloheximide was added 5 h after PHA activation, when the transcription of both messengers had already been turned on, suggesting the presence of the repressor mechanism proposed for IFN-beta 1 and IFN-beta 2 mRNAs in fibroblasts. In the absence of PHA activation, cycloheximide did not induce IFN-beta 2 mRNA transcription as it did in fibroblasts and moreover prevented the accumulation of the messenger observed in the control cells. In contrast to IFN-beta 2 mRNA, cycloheximide treatment of lymphocytes produced a slight accumulation of IFN-gamma mRNA. This accumulation was already detectable 6 h posttreatment and its level remained unchanged for up to 24 h. Addition of actinomycin D, 5 h after PHA activation, did not impair the shut off and accelerated the decay of IFN messengers.

The in vitro effect of retinol on human gingival epithelium. II. Modulation of Langerhans cell markers and interleukin-1 production

The in vitro influence of retinol on the markers of gingival Langerhans cells (LC) was investigated using an organ culture system. Retinol at a dose of 5 micrograms/ml produced an increase in the density of T6-positive cells within the epithelium which peaked during the first 24 h of culture. LC HLA-DR and ATPase markers were maintained for the same period, while all markers were depressed after 72 h. These effects were not seen in explants cultured in conventional or alcohol-enriched media, in which all markers were lost in an exponential fashion. In addition to modulation of LC markers, retinol treatment also prolonged the expression of HLA-DR antigens by gingival keratinocytes. These findings, together with the augmented production of interleukin-1-like activity by retinol-treated gingival organ cultures suggest that low doses of retinol may alter immune reactions within epithelia via stimulation of both keratinocytes and LC.