A recombinant heavy chain antibody approach blocks ART2 mediated deletion of an iNKT cell population that upon activation inhibits autoimmune diabetes. J Autoimmun 2010 Mar;34(2):145-54
Date
10/03/2009Pubmed ID
19796917Pubmed Central ID
PMC2822066DOI
10.1016/j.jaut.2009.08.012Scopus ID
2-s2.0-75349113325 (requires institutional sign-in at Scopus site) 29 CitationsAbstract
The ectoenzyme ADP-ribosyltransferase 2.2 (ART2.2) can apoptotically delete various T-cell subsets. Depending on the involved apoptotic T-cell subset, enhanced ART2.2 activity could result in immunosuppression or autoimmunity. Diminished activity of the CD38 ectoenzyme that normally represents a counter-regulatory competitor for the NAD substrate represents one mechanism enhancing ART2.2 activity. Hence, it would be desirable to develop an agent that efficiently blocks ART2.2 activity in vivo. While the llama derived recombinant s+16 single domain antibody overcame the difficulty of specifically targeting the ART2.2 catalytic site potential therapeutic use of this reagent is limited due to short in vivo persistence. Thus, we tested if a modified version of s+16 incorporating the murine IgG1 Fc tail (s+16Fc) mediated long-term efficient in vivo suppression of ART2.2. We reasoned an ideal model to test the s+16Fc reagent were NOD mice in which genetic ablation of CD38 results in an ART2.2 mediated reduction in already sub-normal numbers of immunoregulatory natural killer T-(NKT) cells to a level that no longer allows them when activated by the super-agonist alpha-galactosylceramide (alpha-GalCer) to elicit effects inhibiting autoimmune type 1 diabetes (T1D) development. Treatment with s+16Fc efficiently mediated long-term in vivo inhibition of ART2.2 activity in NOD.CD38(null) mice, restoring their iNKT cell numbers to levels that upon alpha-GalCer activation were capable of inhibiting T1D development.
Author List
Scheuplein F, Rissiek B, Driver JP, Chen YG, Koch-Nolte F, Serreze DVAuthor
Yi-Guang Chen PhD Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ADP Ribose TransferasesADP-ribosyl Cyclase 1
Animals
Diabetes Mellitus, Type 1
Female
Galactosylceramides
Immunoglobulin Heavy Chains
Lymphocyte Activation
Lymphocyte Depletion
Mice
Mice, Knockout
Mice, Transgenic
Natural Killer T-Cells
Protein Engineering
Recombinant Fusion Proteins
T-Lymphocytes, Regulatory
