title: Lycopene inhibits lymphocyte proliferation through mechanisms dependent on early cell activation.
abstract: METHODS
  Epidemiological evidence suggests that lycopene is potentially cardio-protective. Recruitment and activation of T cells in the arterial wall is a critical process during atherogenesis, but the effects of lycopene on T-cell response remain to be elucidated. We aimed to determine whether lycopene could modulate T-cell function and activity.
  
  
  RESULTS
  Peripheral blood mononuclear cells from 16 healthy adults were cultured in the presence of lycopene-enriched liposomes (0-2.9 μg lycopene/mL) with or without mitogens. Cell cycle as well as the expression of CD69 (marker of early cell activation), CD25 (IL-2 receptor), and CD11a (late activation marker) were measured in T cells, T-helper cells, and T-cytotoxic cells by flow cytometry. IL-2 secretion and cell proliferation were determined by ELISA and [³H]-thymidine incorporation, respectively. Lycopene significantly inhibited lymphocyte proliferation (up to 40%) in activated cells. Lycopene also significantly inhibited CD69 expression (by up to 12%) as well as IL-2 secretion (by up to 29%). However, CD25 and CD11a expression as well as the cell-cycle profile were unaffected by lycopene.
  
  
  CONCLUSIONS
  Lycopene influences lymphocyte proliferation through its effects on processes involved in early cellular activation, providing one possible mechanism to explain the beneficial effects of tomato-rich diets against cardiovascular disease.
authors: School of Medicine and Dentistry, Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen, Scotland, United Kingdom.
authors: Lynsey M
authors: LM
authors: Mills
authors: Heather
authors: H
authors: Wilson
authors: Frank
authors: F
authors: Thies
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D040881:CD11a Antigen / Q000378:metabolism; D002316:Cardiotonic Agents / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000378:metabolism*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D007700:Kinetics; D037181:Lectins, C-Type / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D000077276:Lycopene; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D055815:Young Adult; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D040881:CD11a Antigen; D002316:Cardiotonic Agents; D002338:Carotenoids; D007166:Immunosuppressive Agents; D053645:Interleukin-2 Receptor alpha Subunit; D037181:Lectins, C-Type; D000077276:Lycopene; D008934:Mitogens; D000099192:CD69 Antigens; C508017:IL2RA protein, human