Title

Th1 to Th2 cytokine shifts in nonobese diabetic mice: sometimes an outcome, rather than the cause, of diabetes resistance elicited by immunostimulation.

Document Type

Article

Publication Date

2001

Keywords

Animal, BCG-Vaccine, Cells-Cultured, Cytokines, Diabetes-Mellitus, Female, Freund's-Adjuvant, Gene-Deletion, Immunity-Natural, Injections-Subcutaneous, Interferon-Type-II, Interleukin-10, Interleukin-4, Islets-of-Langerhans, Lymphocyte-Transformation, Mice-Inbred-NOD, Mice-Knockout, Muromonab-CD3, RNA-Messenger, Receptors-Antigen-T-Cell, Th1-Cells, Th2-Cells, Transforming-Growth-Factor-beta

JAX Source

J Immunol 2001 Jan; 166(2):1352-9.

Grant

AI41469/AI/NIAID, DK46266/DK/NIDDK, DK51090/DK/NIDDK

Abstract

Numerous immunostimulatory protocols inhibit the development of T cell-mediated autoimmune insulin-dependent diabetes mellitus (IDDM) in the nonobese diabetic (NOD) mouse model. Many of these protocols, including treatment with the nonspecific immunostimulatory agents CFA or bacillus Calmette-Guerin (BCG) vaccine, have been reported to mediate protection by skewing the pattern of cytokines produced by pancreatic beta-cell autoreactive T cells from a Th1 (IFN-gamma) to a Th2 (IL-4 and IL-10) profile. However, most of these studies have documented associations between such cytokine shifts and disease protection rather than a cause/effect relationship. To partially address this issue we produced NOD mice genetically deficient in IFN-gamma, IL-4, or IL-10. Elimination of any of these cytokines did not significantly alter the rate of spontaneous IDDM development. Additional experiments using these mice confirmed that CFA- or BCG-elicited diabetes protection is associated with a decreased IFN-gamma to IL-4 mRNA ratio within T cell-infiltrated pancreatic islets, but this is a secondary consequence rather than the cause of disease resistance. Unexpectedly, we also found that the ability of BCG and, to a lesser extent, CFA to inhibit IDDM development in standard NOD mice is actually dependent upon the presence of the Th1 cytokine, IFN-gamma. Collectively, our studies demonstrate that while Th1 and Th2 cytokine shifts may occur among beta-cell autoreactive T cells of NOD mice protected from overt IDDM by various immunomodulatory therapies, it cannot automatically be assumed that this is the cause of their disease resistance.