A soluble LAG-3 protein as an immunopotentiator for therapeutic vaccines: Preclinical evaluation of IMP321

Vaccine. 2006 Jun 29;24(26):5426-33. doi: 10.1016/j.vaccine.2006.03.050. Epub 2006 Mar 31.


A soluble LAG-3 (CD223) molecule (sLAG-3) is a natural high affinity ligand for MHC class II. It is known to induce maturation of monocyte-derived dendritic cells in vitro and is used as a vaccine adjuvant to induce CD4 Th1 and CD8 T cell responses in vivo. The work presented herein was performed to study the biological activity of a preclinical grade human sLAG-3 protein, called IMP321: (i) binding on murine APC, (ii) induction of dendritic cell maturation, (iii) safety of repeated injections in mice. The results show that IMP321 binds MHC class II(+) murine APC, induces the maturation of dendritic cells and is well tolerated either injected alone or as an adjuvant with strongly immunogenic antigens.

MeSH terms

  • Adjuvants, Immunologic / administration & dosage*
  • Adjuvants, Immunologic / pharmacology*
  • Animals
  • Antigens, CD / administration & dosage*
  • Antigens, CD / immunology*
  • Cell Differentiation
  • Cells, Cultured
  • Dendritic Cells / drug effects
  • Dendritic Cells / metabolism
  • Female
  • Genes, MHC Class II
  • Humans
  • Lymphocyte Activation Gene 3 Protein
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Phenotype
  • Protein Binding
  • Vaccines / immunology*


  • Adjuvants, Immunologic
  • Antigens, CD
  • Vaccines
  • Lymphocyte Activation Gene 3 Protein