Interplay between human adipocytes and T lymphocytes in obesity: CCL20 as an adipochemokine and T lymphocytes as lipogenic modulators.
OBJECTIVE
Adipose tissue (AT) plays a major role in the low-grade inflammatory state associated with obesity. The aim of the present study was to characterize the human AT lymphocytes (ATLs) and to analyze their interactions with adipocytes.


RESULTS
Human ATL subsets were characterized by flow cytometry in subcutaneous ATs from 92 individuals with body mass index (BMI) ranging from 19 to 43 kg/m(2) and in paired biopsies of subcutaneous and visceral AT from 45 class II/III obese patients. CD3(+) ATLs were composed of effector and memory CD4(+) helper and CD8(+) cytotoxic T cells. The number of ATLs correlated positively with BMI and was higher in visceral than subcutaneous AT. Mature adipocytes stimulated the migration of ATLs and released the chemokine CCL20, the receptor of which (CCR6) was expressed in ATLs. The expression of adipocyte CCL20 was positively correlated with BMI and increased in visceral compared to subcutaneous adipocytes. ATLs expressed inflammatory markers and released interferon gamma (IFN gamma). Progenitor and adipocyte treatment with ATL-conditioned media reduced the insulin-mediated upregulation of lipogenic enzymes, an effect involving IFN gamma.


CONCLUSIONS
Therefore, crosstalk occurs between adipocytes and lymphocytes within human AT involving T cell chemoattraction by adipocytes and modulation of lipogenesis by ATLs.
Duffaut
Carine
C
Institut National de la Santé et de la Recherche Médicale (INSERM), U858, Toulouse, France.
Zakaroff-Girard
Alexia
A
Bourlier
Virginie
V
Decaunes
Pauline
P
Maumus
Marie
M
Chiotasso
Patrick
P
Sengenès
Coralie
C
Lafontan
Max
M
Galitzky
Jean
J
Bouloumié
Anne
A
D017667:Adipocytes / Q000276:immunology*; D050154:Adiposity; D000328:Adult; D015992:Body Mass Index; D017252:CD3 Complex / Q000032:analysis; D054418:Chemokine CCL20 / Q000032:analysis / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000502:physiology; D050155:Lipogenesis; D008875:Middle Aged; D009765:Obesity / Q000276:immunology*; D050151:Subcutaneous Fat / Q000276:immunology; D013601:T-Lymphocytes / Q000502:physiology*
C108355:CCL20 protein, human; D017252:CD3 Complex; D054418:Chemokine CCL20; D007371:Interferon-gamma