CD4+ and CD8+ T cells mediated direct cytotoxic effect against Trichophyton rubrum and Trichophyton mentagrophytes.
BACKGROUND
The cellular immune system is the most dominant factor in curing acute dermatophytosis. However, the exact immune mechanisms involved in generating this defense are complex and still obscure. The aim of this study was to investigate the fungicidal mechanism of T cells in the normal population versus patients with chronic fungal infections.


METHODS
Thirty patients were included in the study: 15 patients with chronic dermatophytosis and 15 normal healthy patients with a history of acute dermatophytosis. The procedures were performed as follows. 1) Proliferation and cytotoxic activity of lymphocytes cultured with various dermatophytes homogenate such as, Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum gypseum. 2) CD4(+) and CD8(+) T cells were separated by magnetic beads before culture with fresh spores of either T. mentagrophytes or T. rubrum. 3) Routine histology and ultrastructural study were performed to illustrate the mode of activity of the T cells against the dermatophytes.


RESULTS
The study showed that both CD4 and CD8 possess cytotoxic activity against dermatophytes. However, the results demonstrated a suppression of lymphocyte proliferation response and a significant lower cytotoxic effect in chronic patients. Ultra structure and histological evaluation of the culture of hyphae with CD4(+) or CD8(+) T cells showed more prominently destructive effects in the culture of cells that had been obtained from normal population than those of patients with long-lasting fungal infections.


CONCLUSIONS
The study suggests a selective impairment of lymphocyte function against dermatophytes, in patients with chronic dermatophytoses.
Waldman
Arie
A
Department of Microbiology, B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Segal
Rina
R
Berdicevsky
Israela
I
Gilhar
Amos
A
D000328:Adult; D003883:Arthrodermataceae / Q000276:immunology / Q000302:isolation & purification*; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D016022:Case-Control Studies; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D002478:Cells, Cultured; D002908:Chronic Disease; D003881:Dermatomycoses / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D006684:HLA-DR Antigens / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008297:Male; D017348:Microscopy, Electron, Scanning Transmission; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D011336:Probability; D014249:Trichophyton / Q000276:immunology* / Q000302:isolation & purification; D055815:Young Adult
D006684:HLA-DR Antigens; D018799:Intercellular Adhesion Molecule-1