Pharmaceuticals of biological origin consisting of bacterial culture suspensions (BCS) as active ingredients have long been used for the treatment of hemorrhoidal diseases and chronic anal pruritogenic eczemas. However, some of these pharmaceuticals often contain glucocorticoids such as hydrocortisone as an anti-inflammatory supplement. Therefore, the question arises whether the claimed immunostimulatory capacity of the bacterial culture suspension might be altered by the steroid. Up to now, numerous reports support the evidence that the stimulation of the different Fc-receptor subtypes on leucocytes result in profound immunoregulatory activities influencing phagocytosis and antigen processing, antibody-dependent cytotoxicity or secretory functions thereby enhancing the overall activities of the immune system towards foreign antigens/pathogens. With these findings in mind it was investigated whether the immunomodulatory capacity(s) of the BCS in the presence of hydrocortisone will be modified by solid-phase bound immunoglobulins (Igs). For this purpose freshly prepared human peripheral blood leucocytes (PBLs) were incubated with different concentrations of the BCS (0.1, 1, 10 micrograms/ml), either with or without fixed human immunoglobulins in the presence of increasing concentrations of hydrocortisone. As a parameter of PBL activation the secretion of different cytokines was measured, e.g. tumor necrosis factor alpha (TNF-alpha), interleukin-10 (IL-10) and granulocyte-macrophage colony stimulating factor (GM-CSF). Cytokines were determined with specific sandwich ELISAs. With this modified cell culture system it was demonstrated that the immunosuppressive activities, normally caused by hydrocortisone, were partially antagonized by the combination of BCS plus fixed Igs. TNF-alpha and GM-CSF were significantly more produced, even in the presence of hydrocortisone, whereas the synthesis of IL-10 was diminished by fixed Igs. However, this effect could be reversed with increasing concentrations of hydrocortisone. These results raise the possibility that in the natural environment, e.g. the rectal mucosa, antigens derived from the BCS are bound by specific Igs, thereby modifying secretory and effector functions of locally present leucocytes in another way as free antigens. The biological relevance of these in vitro data with respect to the therapeutic benefit of the BCS preparations with hydrocortisone will be discussed considering recent findings in the literature.

An in vitro system with macrophages from individual mice was established to study their listericidal capacity. Because no antibiotics were used, bacterial killing was really due to macrophages in short-term culture. To restrict the extracellular growth of bacteria, cell culture medium was changed at 1-h intervals. We demonstrated that intracellular growth of listeria in macrophage pools from untreated animals varies considerably. Obviously, preactivated macrophages are constantly present, so that the common procedure of using macrophage pools from several animals is no longer acceptable. In addition, we demonstrated that in vitro mixtures of listeria-immune macrophages of one animal with cells from untreated animals at different ratios exhibit enhanced bacterial killing above a mere additive effect. Consequently, by using macrophages from individual untreated mice, we found that cells of different animals exhibited various activation stages, although unstimulated, inbred specific-pathogen-free mice of the same age, weight, and sex were used. When equal numbers of macrophages from untreated separate animals were mixed in vitro, intracellular growth of listeria was only moderate; that is, the number of preactivated macrophages of the individual animals determined listerial growth in the pooled preparation. Furthermore, we showed that identical doses of phorbol myristate acetate exerted different effects on the listericidal activities of macrophages as a function of their preactivation states. These experiments clearly demonstrate the advantage of using macrophages from individual mice for in vitro studies of macrophage activation. C57BL/6 mice received 1 x 105 to 2 x 105 viable listeria (50% lethal dose, 9 x 105 listeria) by intraperitoneal injection.

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Autovaccines are prepared from autologous, human, non-pathogenic, "rough" variants of E. coli derived from the stool flora of individuals according to a highly standardized procedure. As a fundamental concept within microbiological therapy, these autovaccines are mainly used to treat chronic inflammatory disorders associated with impaired immune reactions resistant to standard therapeutic treatments. Generally, immunomodulatory effects of outer membrane components or cell wall fragments of gram-negative bacteria on innate or adaptive immunity are widely accepted but nevertheless mechanisms of actions of these autovaccines remained obscure, despite some recent publication about other autovaccine preparations of different origin. Hence, immunomodulating properties of autovaccine were investigated in a pilot study with 78 outpatients with variable disorders ranging from recurrent respiratory infections to diffuse gastrointestinal complaints. Patients received their autologous bacteria parenterally in increasing doses. Before application and 4 to 6 weeks after application of autovaccine, blood samples of the patients were taken to investigate a range of immunological parameters such as acute phase proteins, serum antibodies and cytokines. The results revealed that autovaccines were able to modulate significantly the release of three potent immunoregulatory cytokines e.g. interferon-gamma, granulocyte-macrophage-colony stimulating factor and interleukin-1 beta, whereas specific humoral immunity remained largely unaffected. From these results it may be concluded that the autovaccine mainly act antigen non-specifically on the cytokine level rather than inducing a specific vaccination. Further studies with more detailed kinetic measurements of cytokines will have to verify these results.

The in uitro immunomodulatory activities of extracts from African medicinal plants have been studied. Certain extracts exerted enhancing effects in a concentration dependent manner on immune cells from three different strains of mice. Among these were an enhancement of phagocytic activity of peritoneal macrophages and tumoricidal potential of macrophages, and stimulation of the oxidative burst of macrophages and granulocytes. In contrast, the proliferative capacity of lymphocytes was only marginally affected. Enhanced macrophage and granulocyte activation was also detected using leucocytes of the LPS nonresponder strain C3H/HeJ. From the latter it can be concluded that the observed stimulatory effects of the plant extracts in u&o were not due to contamination with lipopolysaccharides.