title: Activation and proliferation of normal resting human T lymphocytes in serum-free culture: role of IL-4 and IL-6.
abstract: Purified human T lymphocytes, completely depleted of accessory cells [i.e. monocytes, large granular lymphocytes (LGL) and B lymphocytes], have been grown in serum-free culture in presence of a mitogenic lectin (phytohaemagglutinin, PHA) and different recombinant cytokines. Only IL-2 and IL-4 induced a marked stimulation of [3H] thymidine ([3H]TdR) uptake, cell proliferation and expression of activation markers [transferrin receptor (TrfR), IL-2R]. The other cytokines (IL-1 alpha, IL-1 beta, IFN-gamma, GM-CSF, TNF-alpha) had no significant effect, except for a moderate, but significant, stimulation of [3H]TdR uptake induced by IL-3. Simultaneous addition of IL-4 and anti-IL-2 neutralizing monoclonal antibodies (mAb) did not modify the effects induced by IL-4 alone. Furthermore, IL-2 was not detected in the supernatant of T cells grown in the presence of PHA and IL-4. Thus, our results indicate that IL-4 acts on T lymphocytes independently of IL-2. We also observed that IL-6 moderately activates DNA synthesis in PHA-stimulated T lymphocytes, but markedly potentiates the proliferative effect of suboptimal amounts of IL-2. In conclusion, the present study suggests that B-cell growth factors, in addition to IL-2, control the proliferation of normal circulating T lymphocytes.
authors.affiliation: Istituto Superiore di Sanità, University La Sapienza, Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Habetswallner
authors.forename: E
authors.initials: E
authors.lastname: Pelosi
authors.forename: D
authors.initials: D
authors.lastname: Bulgarini
authors.forename: A
authors.initials: A
authors.lastname: Camagna
authors.forename: P
authors.initials: P
authors.lastname: Samoggia
authors.forename: E
authors.initials: E
authors.lastname: Montesoro
authors.forename: G
authors.initials: G
authors.lastname: Giannella
authors.forename: D
authors.initials: D
authors.lastname: Lazzaro
authors.forename: G
authors.initials: G
authors.lastname: Isacchi
authors.forename: U
authors.initials: U
authors.lastname: Testa
mesh_terms: D002478:Cells, Cultured; D003470:Culture Media; D006801:Humans; D015847:Interleukin-4; D015850:Interleukin-6; D007378:Interleukins / Q000276:immunology*; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D003470:Culture Media; D015850:Interleukin-6; D007378:Interleukins; D015847:Interleukin-4