muramidase and Acne-Vulgaris

Although many cytokines have been implicated in the development and persistence of inflammatory immune responses, it is unknown if any of these are important in inflammatory acne. This study investigated the production of the proinflammatory cytokines interleukin-8 (IL-8), IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) by human monocytic cell lines, ThP-1 and U937, and by freshly isolated peripheral blood mononuclear cells from acne patients. Both Propionibacterium acnes and supernatants obtained from 72-h P. acnes cultures could induce significant concentrations of IL-1 beta, TNF-alpha, and IL-8 by both cell lines and by peripheral blood mononuclear cells as determined by enzyme-linked immunosorbent assay. There was no significant difference between acne and non-acne subjects. Endotoxin quantification and addition of polymyxin B to assays indicated no lipopolysaccharide (LPS) contamination. P. acnes supernatant was fractionated into components with molecular weights of < 3,000, < 10,000, and < 30,000 and assayed for the ability to induce IL-8 and TNF production in ThP-1 cells. Nearly 90% of the original activity was found in the < 30,000-molecular-weight fraction, 50% was in the < 10,000-molecular-weight fraction, and only 15% remained in the < 3,000-molecular-weight fraction. The effluent from the < 3,000-molecular-weight fraction contained about 70% activity, indicating that the inducing factor was not retained in the membrane. Incubation of P. acnes supernatant with various concentrations of mutanolysin or lysozyme resulted in a loss of 60% of the original activity. The addition of jimson lectin, which binds peptidoglycan, resulted in a loss of 70% of the activity in a dose-response manner, whereas peanut lectin had little or no effect on the activity. Heating of the P. acnes supernatant to 65 degrees C also had no effect on the activity. Blocking of CD14, a receptor for both LPS and peptidoglycan, reduced cytokine production by > 50%, suggesting that the soluble stimulating factor may be a secreted form of peptidoglycan-polysaccharide.

Topics: Acne Vulgaris; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Cell Wall; Cells, Cultured; Chronic Disease; Endopeptidases; Endotoxins; Humans; In Vitro Techniques; Inflammation; Interleukin-1; Interleukin-8; Keratinocytes; Lipopolysaccharide Receptors; Monocytes; Muramidase; Propionibacterium acnes; Tumor Necrosis Factor-alpha

Propionibacterium acnes cells were tested for the ability to trigger lysosomal hydrolase release from human polymorphonuclear leukocytes. Representative strains of P. acnes serotype I and II failed to stimulate lysosomal release in the absence of serum. P. acnes growth culture supernatants failed to trigger release under any test condition. Addition of fresh or heat-inactivated human serum resulted in lysosomal hydrolase release directly proportional to the number of P. acnes/PMN. Pooled sera from acne patients, with a high anti-P. acnes titer stimulated release to P. acnes. Preabsorption of this reagent with P. acnes cells reduced the anti-P. acnes titer and produced 93.37 +/- 11.49% inhibition of lysosomal enzyme release compared to unabsorbed anti-serum. Electron microscopy indicated that P. acnes was readily phagocytosed by PMNs when fresh or heated serum was present.

Topics: Acne Vulgaris; Humans; In Vitro Techniques; Inflammation; Muramidase; Neutrophils; Phagocytosis; Propionibacterium acnes