Resolution of inflammatory acne vulgaris may involve regulation of CD4+ T-cell responses to Propionibacterium acnes.
BACKGROUND
Propionibacterium acnes has been strongly implicated in inflammatory acne. However, its role in the disease is unclear. It has been hypothesized that an immune response to P. acnes and/or P. acnes heat shock proteins (HSPs) may play a role in the pathogenesis of inflammatory acne.


OBJECTIVE
To compare the cell-mediated immune response to P. acnes and HSPs in acne patients, nonacne controls and individuals with resolved acne.


METHODS
The proliferative response of peripheral blood mononuclear cells (PBMC) from acne patients, resolved acne donors and healthy controls to P. acnes, P. acnes HSP60 and HSP70, and mycobacterial HSPs was assessed by lymphocyte transformation assay (LTA). The proliferative response of purified CD4+ T cells was further analysed by limiting dilution analysis (LDA). Contingency tables (G-test) were used to analyse the proportion of individuals in each group showing a positive proliferative response for LTA or data fitting single-hit kinetics for LDA.


RESULTS
Analysis of stimulation of PBMC with P. acnes, P. acnes HSP60 and HSP70 in the LTA showed the proportion of positive responders to be independent of subject group. However, the proportion of acne patients with a positive response to mycobacterial HSPs was significantly higher than those for the other subject groups. Analysis of LDA data showed the proportion of resolved donors with responses to P. acnes fitting the single-hit kinetics model to be significantly lower than those of the other groups. There were no significant differences in responses to other antigens.


CONCLUSIONS
The significantly lower proportion of resolved donors demonstrating a single-hit kinetics response to P. acnes by LDA may represent negative regulation of the CD4+ T-cell response to P. acnes in these subjects.
Wilcox
H E
HE
Skin Research Centre, Institute of Molecular and Cellular Biology, Garstang Building, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
Farrar
M D
MD
Cunliffe
W J
WJ
Holland
K T
KT
Ingham
E
E
D000152:Acne Vulgaris / Q000276:immunology* / Q000382:microbiology; D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D018834:Chaperonin 60 / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D011425:Propionibacterium acnes / Q000276:immunology*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D018834:Chaperonin 60; D018840:HSP70 Heat-Shock Proteins