Logo image
IL-2 limits IL-12 enhanced lymphocyte proliferation during Leishmania amazonensis infection
Journal article   Open access   Peer reviewed

IL-2 limits IL-12 enhanced lymphocyte proliferation during Leishmania amazonensis infection

Amanda E Ramer-Tait, Christine A Petersen and Douglas E Jones
Cellular immunology, Vol.270(1), pp.32-39
2011
DOI: 10.1016/j.cellimm.2011.03.016
PMCID: PMC3129441
PMID: 21481338
url
https://doi.org/10.1016/j.cellimm.2011.03.016View
Published (Version of record) Open Access

Abstract

C3H mice infected with Leishmania amazonensis develop persistent, localized lesions with high parasite loads. During infection, memory/effector CD44 hiCD4 + T cells proliferate and produce IL-2, but do not polarize to a known effector phenotype. Previous studies have demonstrated IL-12 is insufficient to skew these antigen-responsive T cells to a functional Th1 response. To determine the mechanism of this IL-12 unresponsiveness, we used an in vitro assay of repeated antigen activation. Memory/effector CD44 hiCD4 + T cells did not increase proliferation in response to either IL-2 or IL-12, although these cytokines upregulated CD25 expression. Neutralization of IL-2 enhanced CD4 + T cell proliferation in response to IL-12. This cross-regulation of IL-12 responsiveness by IL-2 was confirmed in vivo by treatment with anti-IL-2 antibodies and IL-12 during antigen challenge of previously infected mice. These results suggest that during chronic infection with L. amazonensis, IL-2 plays a dominant, immunosuppressive role independent of identifiable conventional T reg cells.
Tolerance IL-2 IL-12 Leishmania T cell

Details

Metrics

Logo image