Allergic delayed skin reactions from lipid fractions of trichophytin

Langerhans cell accumulation in chronic tinea pedis and pityriasis versicolor

Persistence of chronic tinea pedis (CTP) and pityriasis (tinea) versicolor (PIVE) has been tentatively attributed to an impaired cellular immune response. Therefore immunophenotyping of the inflammatory infiltrates in both disorders was performed in order to detect possible defects in cellular defence. The results of the present study show a dominance of memory T cells, an accumulation of macrophages and lack of B cells. A very prominent feature in CTP and especially PIVE was a marked accumulation of Langerhans cells (LCs) in the epidermis, mostly without expression of CD4. Furthermore, reduced expression of cellular activation markers and the presence of suppressor T cells was noted. In general, the cellular response in PIVE appeared to be slightly stronger than in CTP. This composition of the inflammatory infiltrates in chronic dermatomycoses is similar to previous findings in a variety of dermatoses. However, in PIVE and CTP local reduction of delayed-type hypersensitivity may occur. The function of LCs in these infections is therefore of special interest.

Hypersensitivity to trichophytin in small animals experimentally infected with Trichophyton equinum

Typical lesions resulting from experimental Trichophyton equinum infection in laboratory animals persisted for 3-4 weeks. Lesions in rabbits were slightly less severe than those in guinea pigs. In experimentally infected dogs lesions persisted for longer and developed in the form of a deep, crusty dermatophytosis. In skin tests with three trichophytins it was shown that specific hypersensitivity resulting from infection of laboratory animals persists for at least 6 months. Stronger local reactions were produced with homologous trichophytins, especially in the final tests after 6 months.

Immunochemical studies of conjugates of isomaltosyl oligosaccharides to lipid. I. Antigenicity of the glycolipids and the production of specific antibodies in rabbits

Isomaltose oligosaccharides varying in size from two sugars, isomaltose (IM2), to seven sugars, isomaltohepatose (IM7), were coupled to stearylamine by reductive amination with sodium cyanoborohydride. Each compound was purified by column chromatography to yield a series of glycolipids containing oligosaccharides differing in length. Stearyl-isomaltotriose to stearyl-IM7 could be incorporated into liposomes and could render them agglutinable by specific antibodies to alpha 1 leads to 6 dextran and could be lysed if complement was also added, whereas those containing stearyl-IM2 were not agglutinated or lysed, indicating that stearyl-IM2 may not be protruding from the liposome surface sufficiently to react with the antibody. Stearyl-isomaltosyl oligosaccharides by themselves or incorporated into liposomes were equally antigenic when emulsified in complete Freund's adjuvant. They elicited pauciclonal responses, and the antibodies were alpha 1 leads to 6 specific, cross-reacted with dextran, and gave semirestricted isoelectric focusing patterns.

Lipids of dermatophytes

This investigation deals with phosphatides and fatty acid content of Epidermophyton floccosum, Microsporum cookie and Trichophyton mentagrophytes during different phases of growth. Total phosphatide content of these dermatophytes decreased with age, which was reflected in constituent major phosphatides. The zwitterionic and anionic phospholipids tended to maintain a constant ratio. Short chain fatty acids increased significantly with age in E. floccosum whereas these fatty acids represented a minor fraction of the total fatty acids in M. cookie and T. mentagrophytes. The ratio of saturated to unsaturated fatty acids increased 4-fold during growth in E. floccosum, whereas this increase was marginal in M. cookie. This ratio decreased in T. mentagrophytes.

Does occupational exposure to glass-fibres increase the general skin reactivity to irritants?

A total of 33 workers at a glass-wool factory were tested (patch tests with glass-fibres and chemical irritants, epicutaneous tests with Trafuril and intracutaneous tests with histamine) before starting to work at the factory and then re-tested after at least 4 weeks of exposure to glass-fibres. No statistically significant differences in the intensity of the skin reactions before and after exposure were found. Thus no general increased irritancy of the normal skin was induced by the continuous exposure to glass-fibres.

Isolation and partial characterization of immunologically reactive fractions from chitinase digested cell wall of Trichophyton mentagrophytes

Cell wall preparations of Trichophyton mentagrophytes were digested with chitinase following which various fractions were isolated by ultrafiltration and Sephadex gel filtration. All fractions isolated contained both polysaccharide and peptide material. A correlation was seen between those fractions capable of eliciting immediate and delayed skin reactions in sensitized guinea pigs and those capable of stimulating the in vitro proliferation of lymphocytes taken from sensitized guinea pigs. These immunologically active fractions also developed precipitin lines with antiserum taken from sensitized animals. A low molecular weight fraction was found to be completely reactive immunologically (UM2(a)), and appeared to have a molecular weight in the range of 2,000--4,000 as assessed by ultrafiltration and gel filtration studies.

Lipid composition of Microsporum gypseum

The lipid composition of Microsporum gypseum has been studied. The lipids amounted to 10.1% and phospholipids to 1.1% of the mycelial dry weight. Phosphatidyl choline, phosphatidyl serine and phosphatidyl ethanolamine were the major components, while lysophosphatidyl choline, and phosphatidyl inositol were present in smaller quantities. Neutral lipids consisted of monoglycerides, diglycerides, triglycerides, free and esterified cholesterol.

Contact sensitizing properties of some fatty acids in dermatophytes

The predominant fatty acids (C10-C18) of dermatophytes were investigated by the Landsteiner-Draize test to establish their allergenicity. It was demonstrated that fatty acids can give rise to sensitization of delayed type in guinea pigs. The middle-chain fatty acids (C10-C12) showed a high allergenicity compared to the (C13-C18) acids with moderate to weak contact sensitizing properties. The fatty acids may act as contact sensitizers and, at least sometimes, be responsible for the skin lesions in dermatophytosis.