UBC Theses and Dissertations
Immunochemical studies on the antigenic properties of the cell wall of Trichophyton mentagrophytes Al-Rammahy, Abdul Khaliq Abdullah
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 ±n vitro proliferation of lymphocytes taken from sensitized guinea pigs. These immunologically active fractions also developed precipitin lines with antiserum taken from sensitized animals. Amino acid analysis of an immunologically active fraction of low molecular weight indicated that the peptide content comprised a limited array of amino acids. This fraction, found to be completely reactive immunologically (UM₂(a)), appeared to have a molecular weight in the range of 2,000-4,000 as assessed by ultrafiltration and gel filtration studies. This fraction, (UM₂(a)) was further degraded by treatment with either a combination of pronase and carboxypeptidase A or with trypsin. Peptides were separated from the carbohydrate-rich fraction by ultrafiltration. The carbohydrate-rich fraction retained the ability to induce both immediate and delayed skin reactions in sensitized guinea pigs and to stimulate the proliferation of sensitized lymphocytes in vitro. The peptide moieties retained reactivity in that they caused delayed reactions and lymphocyte proliferation but were unable to induce immediate or Arthus reactions in sensitized animals. Tryptic peptides from UM₂(a) were purified by ion exchange chromatography. A high proportion of these peptides demonstrated immunological activity at both the cellular and humoral level since they were capable of inducing delayed reactions and/or lymphocyte transformation, as well as being capable of blocking the complement fixation reaction between UM₂(a) and specific antiserum.
Item Citations and Data