Do regulatory T cells contribute to Th1 skewness in obesity?
BACKGROUND
Recent data suggest that an increased prevalence of interferon-gamma (IFN-gamma) producing CD4 (+) cells is present in obesity. Regulatory T cells (Tregs) have a strong impact on activation and proliferation of CD4 (+) lymphocytes. Data are not available about Tregs and their possible contribution to chronic mild inflammation in obesity.


METHODS
We investigated the prevalence of Tregs in obese children. We also collected data about dendritic cells and monocytes (so-called antigen presenting cells, APCs), important modulators of Tregs and we determined the cytokine production of CD4 (+) lymphocytes, the main target cells of Tregs.


METHODS
Twelve obese children and 10 healthy age-matched controls have been enrolled. For flow cytometric analyses, peripheral blood mononuclear cells were used. We determined the prevalence of Tregs by Foxp3 expression of CD4 (+) cells; prevalence of myeloid and plasmacytoid dendritic cells (DCs); prevalence of tumor necrosis factor (TNF)-alpha and interleukin(IL)-12 producing monocytes; and prevalence of IL-2, IL-4 and IFN-gamma producing CD4 (+) cells.


RESULTS
The prevalence of Tregs, DCs, TNF-alpha and IL-12 producing macrophages, IL-2 and IFN-gamma producing CD4 (+) cells was similar in both groups. The prevalence of IL-4 producing CD4 (+) cells was lower in obese children than in healthy controls (p=0.028). The ratio of IFN-gamma (+)/ IL-4 (+) CD4 (+) cells was higher in obese children than in those with normal weight (p=0.046).


CONCLUSIONS
CD4 (+) reactions are polarized toward Th1 direction in obesity. The unaltered number of Treg and APCs suggests that these immune regulator cells do not contribute to altered immune status in obese children.
Svec
P
P
Research Group of Pediatrics and Nephrology, Hungarian Academy of Sciences, Budapest, Hungary. peter.svec@gmail.com
Vásárhelyi
B
B
Pászthy
B
B
Körner
A
A
Kovács
L
L
Tulassay
T
T
Treszl
A
A
D000293:Adolescent; D001772:Blood Cell Count; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D003713:Dendritic Cells / Q000166:cytology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D009765:Obesity / Q000276:immunology / Q000503:physiopathology*; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D018417:Th1 Cells / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D002097:C-Reactive Protein