title: Growth hormone in the presence of laminin modulates interaction of human thymic epithelial cells and thymocytes in vitro.
abstract: BACKGROUND
  Several evidences indicate that hormones and neuropeptides function as immunomodulators. Among these, growth hormone (GH) is known to act on the thymic microenvironment, supporting its role in thymocyte differentiation. The aim of this study was to evaluate the effect of GH on human thymocytes and thymic epithelial cells (TEC) in the presence of laminin.
  
  
  RESULTS
  GH increased thymocyte adhesion on BSA-coated and further on laminin-coated surfaces. The number of migrating cells in laminin-coated membrane was higher in GH-treated thymocyte group. In both results, VLA-6 expression on thymocytes was constant. Also, treatment with GH enhanced laminin production by TEC after 24 h in culture. However, VLA-6 integrin expression on TEC remained unchanged. Finally, TEC/thymocyte co-culture model demonstrated that GH elevated absolute number of double-negative (CD4(-)CD8(-)) and single-positive CD4(+) and CD8(+) thymocytes. A decrease in cell number was noted in double-positive (CD4(+)CD8(+)) thymocytes.
  
  
  CONCLUSIONS
  The results of this study demonstrate that GH is capable of enhancing the migratory capacity of human thymocytes in the presence of laminin and promotes modulation of thymocyte subsets after co-culture with TEC.
authors: Laboratory of Cell Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Alagoas, Brazil.
authors: Marvin Paulo
authors: MP
authors: Lins
authors: Laboratory of Cell Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Alagoas, Brazil.
authors: Larissa Fernanda
authors: LF
authors: de Araújo Vieira
authors: Laboratory of Cell Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Alagoas, Brazil.
authors: Alfredo Aurélio Marinho
authors: AA
authors: Rosa
authors: Laboratory of Cell Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceió, Alagoas, Brazil. smaniotto@icbs.ufal.br.
authors: Salete
authors: S
authors: Smaniotto
mesh_terms: D000704:Analysis of Variance; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000187:drug effects*; D005434:Flow Cytometry / Q000379:methods; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D039121:Integrin alpha6beta1 / Q000032:analysis / Q000378:metabolism; D007797:Laminin / Q000096:biosynthesis* / Q000187:drug effects; D012016:Reference Values; D060168:Thymocytes / Q000187:drug effects*; D013950:Thymus Gland / Q000166:cytology* / Q000378:metabolism; D013997:Time Factors
chemical_list: D039121:Integrin alpha6beta1; D007797:Laminin; D013006:Growth Hormone
keywords: Growth hormone; Laminin; Thymic epithelial cells; Thymocyte