Effect of the progesterone-inducible proteins human lactoferrin and chicken avidin on lymphocyte proliferation.

Lactoferrin and avidin are progesterone-inducible glycoproteins in the human and chicken reproductive tracts, respectively. The effect of these proteins on lymphocyte proliferation was studied. The results showed that both proteins suppressed Concanavalin A (Con A)-induced responses so that a 10(3)-fold higher concentration of Con A was required for an optimal response. In contrast, avidin and lactoferrin had no effect on lymphocyte proliferation induced by other mitogens, tuberculin PPD or allogeneic cells. The effect of lactoferrin and avidin on lymphocyte proliferation seem to be caused by their binding to Con A. The significance of these findings is discussed.

Dialysable leukocyte extracts (transfer factor) augment nonspecifically keyhole limpet haemocyanin and horseshoe crab haemocyanin skin reactivity in unimmunized human recipients.

Dialysable leukocyte extracts (DLE) may induce marked changes in the immune expression of human recipients. It is unclear whether the conversion of skin reactivity by DLE is due to a donor-related specific transfer factor or to an antigen nonspecific augmenting factor which enhances a preexisting low-level response in DLE recipients. In this study, DLE from immunized and unimmunized human and calf donors or saline was administered to 88 medical students. The recipient population demonstrated minimal background responses to the test antigens keyhole limpet haemocyanin (KLH) and horseshoe crab haemocyanin (HCH). The results indicate that the DLE preparations from both immunized and unimmunized donors significantly stimulated skin reactivity but not in vitro responses to both KLH and HCH in the recipient population. The results suggest that these DLE preparations contain an immunologically nonspecific augmentor, which stimulates a preexisting low-level response in the unimmunized population to become a clearly observable skin reaction.

Augmentation of delayed-type hypersensitivity in antigen-primed guinea pigs by human dialyzable leukocyte extract. Chromatographic and enzymatic characterization of the active principle.

Column chromatographic purification and sensitivity towards enzymatic treatments of dialyzable transfer factor (TFd), the immunologically specific component of dialyzable leukocyte extract (DLE), have previously been used in its biochemical characterisation. In the present work we studied the effect of enzymes and the Sephadex G-10 chromatographic separation of the components of DLE augmenting delayed-type hypersensitivity. Skin reactivities to streptokinase-streptodornase (SK-SD) and tuberculin PPD were significantly augmented by injecting DLE into antigen-primed guinea pigs. The augmentation caused by DLE treatment correlated to the pre-existing level of immunity in the recipients. Most of the augmentory activity resided in 2 adjacent fractions, eluting early from a Sephadex G-10 column. This augmentation was destroyed by alkaline hydrolysis, by treatment with pronase, proteinase K, ribonuclease, and nuclease P1, but not by alkaline phosphatase or phosphodiesterase II. The observed sensitivities towards these enzymes, except that for ribonuclease, were closely similar to those described for the specific TFd component of DLE. These results are compatible with the idea that either the nonspecific augmenting and the specific TFd molecules are principally similar, or that the TFd molecules, in addition to their capacity to transfer specific immunity, also have an augmenting effect, which needs in its manifestation a sub-threshold dose of immunogen.

Human transfer factor in vitro. II. Augmentation of the secretion of leucocyte migration inhibitory factor (LIF) by leucocyte dialysate and by its components L-serine and glycine.

The effect of human transfer factor (TF) or its components L-serine and/or glycine in tuberculin (PPD), or leucoagglutinin (LA) induced leucocyte migration inhibitory factor (LIF) secretion was studied. Augmentation of LIF secretion was seen with low concentration ( = 0.078 g/l) of TF when lymphocytes were cultured in minimum essential medium for suspension cultures (MEM-S), a culture medium lacking L-serine and glycine. High concentrations (0.3125-5.0 g/l dry weight) of TF were inhibitory in MEM-S. In RPMI 1640, a culture medium containing L-serine and glycine, TF was either inhibitory or had no effect. The combination of L-serine and glycine, at concentrations equivalent or lower than the optimum of TF, had an augmenting effect on LIF secretion identical to that of TF, but no inhibition at higher concentrations was seen. The results indicate that human TF contains components which have suppressive or augmenting effects on LIF secretion in vitro. The augmenting effect may be mainly due to L-serine and glycine and thus not related to TF's activity in vivo.