A Study on the Number of Circulating CD4+CD25+Foxp3+ Regulatory T Cells and CD4+CD25-Foxp3+ T Cells in Psoriasis / 대한피부과학회지

BACKGROUND: Regulatory T cells (Treg) are able to inhibit the immunological response and maintain cutaneous immunological homeostasis, thus preventing autoimmunity against itself. In several studies, the importance of CD4+CD25+Foxp3+ Treg in psoriasis has been examined, using the peripheral blood of patients. However, limited studies on Treg are available and shows conflicting results. Recently, CD4+CD25-Foxp3+ T cells were identified as being the peripheral reservoir of CD4+CD25+Foxp3+ Treg. OBJECTIVE: The purpose of this study was to investigate differences in the CD4+CD25+Foxp3+ Treg and CD4+CD25- Foxp3+ T cell counts between patients with psoriasis and normal controls. METHODS: For phenotypic analysis, the proportions and absolute cell numbers of CD4+CD25+Foxp3+ Treg and CD4+CD25-Foxp3+ T cells in the peripheral blood were examined by flow cytometry. The correlation between the CD4+CD25+Foxp3+ Treg count and other parameters (age of onset, disease duration, BSA, psoriasis area and severity index score, and clinical stage) was also analyzed. RESULTS: Although the CD4+CD25+Foxp3+ Treg count was slightly increased while the number of CD4+CD25- Foxp3+ T cells was slightly decreased in psoriasis patients than that of the controls, the differences between the groups were not statistically significant (5.27+/-2.60 vs. 4.70+/-1.35, p>0.05; 1.56+/-1.07 vs. 1.93+/-1.08, p>0.05). The CD4+CD25+Foxp3+ Treg count did not correlate with the tested parameters except for the clinical stage of psoriasis. The mean+/-SD number of CD4+CD25+Foxp3+ Treg in the stable phase was higher than that in the progressive phase (7.26+/-2.58 vs. 4.35+/-2.10, p0.05). CONCLUSION: These findings suggest that the CD4+CD25+Foxp3+ Treg count alone is insufficient to explain the pathogenesis and severity of psoriasis. However, a decrease in circulating CD4+CD25+Foxp3+ Treg is likely to be correlated with an aggravation of psoriasis.

A Study on the Number of Circulating CD4+CD25+Foxp3+ Regulatory T Cells and CD4+CD25-Foxp3+ T Cells in Psoriasis / 대한피부과학회지

BACKGROUND: Regulatory T cells (Treg) are able to inhibit the immunological response and maintain cutaneous immunological homeostasis, thus preventing autoimmunity against itself. In several studies, the importance of CD4+CD25+Foxp3+ Treg in psoriasis has been examined, using the peripheral blood of patients. However, limited studies on Treg are available and shows conflicting results. Recently, CD4+CD25-Foxp3+ T cells were identified as being the peripheral reservoir of CD4+CD25+Foxp3+ Treg. OBJECTIVE: The purpose of this study was to investigate differences in the CD4+CD25+Foxp3+ Treg and CD4+CD25- Foxp3+ T cell counts between patients with psoriasis and normal controls. METHODS: For phenotypic analysis, the proportions and absolute cell numbers of CD4+CD25+Foxp3+ Treg and CD4+CD25-Foxp3+ T cells in the peripheral blood were examined by flow cytometry. The correlation between the CD4+CD25+Foxp3+ Treg count and other parameters (age of onset, disease duration, BSA, psoriasis area and severity index score, and clinical stage) was also analyzed. RESULTS: Although the CD4+CD25+Foxp3+ Treg count was slightly increased while the number of CD4+CD25- Foxp3+ T cells was slightly decreased in psoriasis patients than that of the controls, the differences between the groups were not statistically significant (5.27+/-2.60 vs. 4.70+/-1.35, p>0.05; 1.56+/-1.07 vs. 1.93+/-1.08, p>0.05). The CD4+CD25+Foxp3+ Treg count did not correlate with the tested parameters except for the clinical stage of psoriasis. The mean+/-SD number of CD4+CD25+Foxp3+ Treg in the stable phase was higher than that in the progressive phase (7.26+/-2.58 vs. 4.35+/-2.10, p0.05). CONCLUSION: These findings suggest that the CD4+CD25+Foxp3+ Treg count alone is insufficient to explain the pathogenesis and severity of psoriasis. However, a decrease in circulating CD4+CD25+Foxp3+ Treg is likely to be correlated with an aggravation of psoriasis.

Age-Related CD4+CD25+Foxp3+ Regulatory T-Cell Responses During Plasmodium berghei ANKA Infection in Mice Susceptible or Resistant to Cerebral Malaria

Different functions have been attributed to CD4+CD25+Foxp3+ regulatory T-cells (Tregs) during malaria infection. Herein, we describe the disparity in Treg response and pro- and anti-inflammatory cytokines during infection with Plasmodium berghei ANKA between young (3-week-old) and middle-aged (8-month-old) C57BL/6 mice. Young mice were susceptible to cerebral malaria (CM), while the middle-aged mice were resistant to CM and succumbed to hyperparasitemia and severe anemia. The levels of pro-inflammatory cytokines, such as TNF-alpha, in young CM-susceptible mice were markedly higher than in middle-aged CM-resistant mice. An increased absolute number of Tregs 3-5 days post-inoculation, co-occurring with elevated IL-10 levels, was observed in middle-aged CM-resistant mice but not in young CM-susceptible mice. Our findings suggest that Treg proliferation might be associated with the suppression of excessive pro-inflammatory Th1 response during early malaria infection, leading to resistance to CM in the middle-aged mice, possibly in an IL-10-dependent manner.

Peripheral Generation of CD4+ CD25+ Foxp3+ Regulatory T Cells

CD4+ CD25+ regulatory T cells (Tregs) expressing the lineage-specific marker Foxp3 represent an important regulatory T cell that is essential for maintaining peripheral tolerance. Although it was believed that Treg development is solely dependent on the thymus, accumulating evidence demonstrates that Tregs can also be induced in the periphery. Considering the various origins of peripherally developed CD4+ CD25+ Foxp3+ regulatory T cells, it seems likely that multiple factors are involved in the peripheral generation of Tregs.