title: Transient accumulation of human mature thymocytes and regulatory T cells with CD28 superagonist in "human immune system" Rag2(-/-)gammac(-/-) mice.
abstract: Efficient and quick reconstitution of T-cell compartments in lymphopenic patients is of great importance to prevent opportunistic infections, but remains difficult to achieve. Human T-cell proliferation in a T-cell-receptor (TCR)-independent manner is possible in vitro with superagonist anti-CD28 antibodies, and such molecules are therefore promising therapeutic tools. Here, we investigated the in vivo effects of superagonist anti-CD28 treatment on human developing and mature T cells, in the recently developed model of "human immune system" BALB/c Rag2(-/-)gammac(-/-) mice. Our results show that superagonist anti-CD28 treatment transiently induces a 7-fold increase in thymocyte numbers and up to 18-fold accumulation of mature thymocytes. The increased thymic production lead to transient accumulation of mature T cells in the periphery at the peak of treatment effect (day 6). In addition, long-term peripheral T-cell depletion was induced. Furthermore, the concomitant selective expansion and accumulation of suppressive CD4+CD25+FoxP3+ T cells was induced in a transient manner. Superagonist anti-CD28 therapy could therefore be of clinical interest in humans, both for beneficial effect on thymic T-cell production as well as regulatory T-cell accumulation.
authors.affiliation: Department of Cell Biology and Histology, Academic Medical Center of the University of Amsterdam (AMC-UvA), Amsterdam, The Netherlands. n.legrand@amc.uva.nl
authors.forename: Nicolas
authors.initials: N
authors.lastname: Legrand
authors.forename: Tom
authors.initials: T
authors.lastname: Cupedo
authors.forename: Anja U
authors.initials: AU
authors.lastname: van Lent
authors.forename: Menno J
authors.initials: MJ
authors.lastname: Ebeli
authors.forename: Kees
authors.initials: K
authors.lastname: Weijer
authors.forename: Thomas
authors.initials: T
authors.lastname: Hanke
authors.forename: Hergen
authors.initials: H
authors.lastname: Spits
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D018106:CD28 Antigens / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000172:deficiency* / Q000276:immunology; D004195:Disease Models, Animal; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D018106:CD28 Antigens; D004268:DNA-Binding Proteins; C499308:Rag2 protein, mouse