However, low doses were as efficient and induced prolonged suppression. It is possible that this prolonged suppression was due to Treg cells, which might be eliminated with high doses of chimeric A9H12 but not, or to a lesser extent, with low doses. That anti-LAG-3 antibodies
can eliminate Treg cells was demonstrated previously in a transplantation model, where very high doses could prevent tolerance induction and even break an established tolerance [15]. The DTH response has been well characterized in immunized animals, including rhesus monkeys [27,28], and humans as an antigen-specific reaction resulting in erythema and induration (within 24–72 h) at the site of injection. It is characterized as a type IV hypersensitivity Doxorubicin molecular weight reaction involving cell-mediated Pirfenidone concentration immunity initiated by CD4 and CD8 T cells. The exposure to Mycobacterium tuberculosis that we used here drives a cytokine-induced differentiation of naive CD4 Th cells to Th1 [29], and therefore can be considered as a surrogate in vivo assay for psoriasis inflammation. In conclusion, we demonstrated that selectively targeting activated T cells with a LAG-3 cytotoxic antibody prevents T cell-driven skin inflammation in a preclinical DTH model in non-human primates. Our data suggest that depleting
pathogen-specific activated LAG-3+ T cells might represent a promising new therapeutic approach in diseases where self-antigens (or alloantigens in the case of transplantation) and activated T cells (e.g. multiple sclerosis, rheumatoid arthritis, psoriasis, different forms of thyroiditis,
diabetes type I) are involved. This work was supported in part by the ‘Progreffe’ foundation, by a grant from the Agence Nationale pour la Recherche no. ANR-06-RIB-010–01 and by a research grant from Immutep SA. The authors thank R. Bredoux for assistance in project new management and C. Mary and A. Cariot for advice in pharmacokinetic evaluation. T. H., F. T. and B. V. are inventors of the WO2008132601(A1) patent application on anti-LAG-3 antibodies. “
“Susceptibility to Chlamydia trachomatis infection is increased by oral contraceptives and modulated by sex hormones. We therefore sought to determine the effects of female sex hormones on the innate immune response to C. trachomatis infection. ECC-1 endometrial cells, pre-treated with oestradiol or progesterone, were infected with C. trachomatis and the host transcriptome analysed by Illumina Sentrix HumanRef-8 microarray. Primary endocervical epithelial cells, prepared at either the proliferative or secretory phase of the menstrual cycle, were infected with C. trachomatis and cytokine gene expression determined by quantitative RT-PCR analysis. Chlamydia trachomatis yield from progesterone-primed ECC-1 cells was significantly reduced compared with oestradiol-treated cells.