Isolation and partial characterization of a keratinocyte proliferative factor produced by Streptococcus pyogenes (strain NY-5)

The significance of stress hormones (glucocorticoids, catecholamines) for eruptions and spontaneous remission phases in psoriasis

BACKGROUND

In an earlier paper, it was described how acute eruptions of psoriasis may be produced in phases of immune deficiency and in the presence of bacterial antigen-releasing inflammatory foci, whereas clinical spontaneous remissions are produced in phases of immunologic activity. Therefore, it was of interest to investigate whether the stress hormones cortisol/epinephrine are involved in triggering such deficiency and activity phases.

METHODS

During a series of investigations lasting up to 3 years in 95 patients, the following were determined: cortisol/epinephrine levels, polyclonal serum immunoglobulins IgM, IgG, and IgA, total serum IgE, complement C3 and C4 proteins, T cells and subpopulations, as well as streptococcal titers ASO/ADNase B, severity index (PASI) RESULTS: Phases of clinical inactivity are associated with the mechanism, "immunologic regulation," where antibacterial titers are elevated, but all other parameters are unremarkable. Eruption phases (in 32 of 95 patients) showed absolute increases in serum cortisol levels and antibacterial titers, and decreases in serum epinephrine (adrenaline) levels. Phases of spontaneous remission (in 25 of 32 patients) showed, in contrast to the eruption phases, absolute increases in serum epinephrine levels, and significant falls in serum cortisol levels and bacterial titers.

CONCLUSIONS

On the basis of these results, the participation of the immune system is confirmed in the pathogenesis of psoriasis, which is subject to control by higher neurohormonal systems. Cortisol may be involved in the clinical eruption phase, and epinephrine in the remission phase. Both hormones are true antagonists and have important effects on the human immune system if produced in excess via the pituitary-adrenal axis. Infection with Streptococcus pyogenes is an additional trigger for the dermatosis.

A case of guttate psoriasis following Kawasaki disease

We report a case of guttate psoriasis following Kawasaki disease, in a patient with Staphylococcus aureus demonstrated in a throat swab. We suggest that preceding staphylococcal infection can play a key role in the pathogenesis of some cases of guttate psoriasis, possibly by the production of superantigens.

The role of superantigens in human diseases: therapeutic implications for the treatment of skin diseases

Although it is well established that immune mechanisms contribute to the pathogenesis of chronic inflammatory skin diseases such as atopic dermatitis (AD) and psoriasis, the actual events that trigger the immunological pathways resulting in these skin diseases are not well understood. Colonization and infection with Staphylococcus aureus and streptococci has been reported to exacerbate AD and psoriasis. Recent studies demonstrating that bacterial toxins can act as superantigens provide mechanism(s) by which S. aureus and streptococci could mediate an inflammatory skin lesion that consists predominantly of activated T-cells and monocytes. This review will explore the diverse mechanisms by which bacterial superantigens can induce skin inflammation following systemic or local infection. These observations provide a new direction for the development of novel approaches for the treatment of skin inflammation.

Insights into the pathogenesis of psoriasis and psoriatic arthritis

Psoriasis and its related arthritis are chronic inflammatory disorders affecting predominantly the skin and synovium. Although their etiology remains to be established, multiple factors seem to play important roles in their pathogenesis. These environmental (eg, infectious agents and trauma), genetic, and immunologic factors are reviewed in this article.

Toxin-mediated streptococcal and staphylococcal disease

After several decades of seemingly decreasing virulence, streptococcal and staphylococcal infections have reemerged as a major source of morbidity and mortality. Within the past 2 decades, not only have well-established diseases such as rheumatic fever begun to reappear. but also many new entities, such as toxic shock syndrome, streptococcal toxic shock syndrome, recurrent toxin-mediated perineal erythema, and recalcitrant erythematous desquamating disorder have been described. Central to the renewed importance of these bacteria has been the production of circulating toxins, which often function as superantigens in causing the clinical manifestations, morbidity and mortality associated with these diseases.

Evidence for a streptococcal superantigen-driven process in acute guttate psoriasis

Recent studies have suggested that T cells play a critical role in the pathogenesis of psoriasis. Guttate psoriasis is a well-defined form of psoriasis frequently associated with streptococcal throat infection. This study tested the hypothesis that T cells in acute guttate psoriasis skin lesions may be activated by streptococcal superantigens. Peripheral blood as well as lesional and perilesional skin biopsies were analyzed for T cell receptor V beta repertoire using monoclonal antibodies against 10 different V beta families. Skin biopsies from all patients with acute guttate psoriasis, but not skin biopsies from patients with acute atopic dermatitis or inflammatory skin lesions induced in normal subjects with sodium lauryl sulfate, demonstrated selective accumulation of V beta 2+ T cells (P < 0.05). The expansion of V beta 2+ T cells occurred in both the CD4+ and the CD8+ T cell subsets. Sequence analysis of T cell receptor beta chain genes of V beta 2-expressing T cells from skin biopsies of patients with guttate psoriasis showed extensive junctional region diversity that is more compatible with a superantigen rather than a conventional (nominal) antigen-driven T cell response. All streptococcal isolates from patients with guttate psoriasis secreted streptococcal pyrogenic exotoxin C, a superantigen known to stimulate marked V beta 2+ T cell expansion. These data support the concept that acute guttate psoriasis is associated with superantigenic stimulation of T cells triggered by streptococcal superantigen(s).

The role of superantigens in skin disease

Staphylococcus aureus and streptococci secrete a large family of exotoxins involved in the pathogenesis of toxic-shock-like syndromes and have been implicated in several autoimmune disorders. These toxins act as prototypic superantigens capable of binding to major histocompatibility complex proteins on antigen-presenting cells outside the antigen peptide-binding groove and can thereby stimulate cytokine release from macrophages. The superantigen-major histocompatibility complex unit is recognized primarily by the variable region of the T-cell receptor beta chain, and by engaging this region, can activate a large portion of the T-cell repertoire. It is thought that the capacity of these toxins to cause the massive stimulation of T cells and accessory cells such as macrophages, Langerhans cells, and activated keratinocytes accounts for most of their pathologic effects. The current review examines the evidence that implicates a role for these superantigens in the pathogenesis of certain skin diseases.

Group A streptococcal pyrogenic exotoxin (scarlet fever toxin) type A and blastogen A are the same protein

Group A streptococcal pyrogenic exotoxins A, B, and C (also known as scarlet fever toxins and erythrogenic toxins) were evaluated for relatedness to another streptococcus-derived lymphocyte mitogen, blastogen A. Streptococcal pyrogenic exotoxin A and blastogen A were immunologically cross-reactive and shared the same molecular weight, N-terminal amino acid sequence, and capacity to stimulate rabbit splenocyte proliferation nonspecifically.

Purification and characterization of streptococcal proliferative factor

Group A streptococcal infections are often associated with scarlet fever and flares of guttate psoriasis. Previous investigation has demonstrated the presence of a factor in streptococcal culture filtrates capable of stimulating proliferation of rabbit keratinocytes in vivo and human lymphocytes in vitro. This report outlines an in vivo method for the production of streptococcal proliferation factor, its purification, and characterization of its physical properties. We cultured Group A streptococci (Type 12, Strain NY5) in synthetic media by in vivo incubation within dialysis casing surgically implanted in rabbit peritoneum. Streptococcal exoproteins were isolated by centrifugation of the bacteria and millipore filtration. Purification of streptococcal proliferative factor was accomplished by differential solubility and molecular sieve was discovered in the resulting product. The relative by SDS gels and molecular sieve chromatography. The sedimentation coefficient determined by sucrose gradient ultracentrifugation is 2.7S. Isoelectric focusing showed minimal microheterogeneity with the pI of the major band being 5.0. Thus, streptococcal proliferative factor can be produced by in vivo incubation of streptococci in synthetic media. Purification entails a rapid 2-step process. The relative molecular weight, sedimentation coefficient and isoelectric points have been established.