Folate-targeted hapten immunotherapy of adjuvant-induced arthritis: Comparison of hapten potencies

Young Su Yi, Wilfredo Ayala-López, Sumith A. Kularatne, Philip Low

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


We have previously reported that disease symptoms can be greatly ameliorated in rodents with adjuvant-induced arthritis (AIA) by first immunizing the rodents against fluorescein and then treating the animals with folate-fluorescein. In this targeted hapten therapy, folate-fluorescein was shown to decorate folate receptor (FR)-expressing activated macrophages with fluorescein (an immunogenic hapten), leading to binding of antifluorescein antibodies and the consequent elimination of the activated macrophages by Fc receptor-expressing immune cells. In the current study, we compare the therapeutic potencies of a variety of FR-targeted haptens in treating the symptoms of AIA in rats. Rats were immunized with either dinitrophenyl (DNP) or trinitrophenyl (TNP) conjugated to keyhole limpet hemocyanin followed by induction of AIA with heat-inactivated Mycobacterium butyricum. Following development of arthritis, rats were treated with one of five folate-hapten conjugates (folate-DNP1, folate-DNP2, folate-DNP3, folate-FITC, or folate-TNP) at two different doses (30 nmol/kg or 200 nmol/kg) 5x/week for 25 days. Symptoms of AIA in treated rats, including paw swelling, arthritis score, splenomegaly, bone erosion, and FR+ activated macrophage density in inflamed tissues, were quantitated over the course of therapy. Although all folate-hapten conjugates promoted a reduction in disease symptoms, folate-TNP and folate-FITC proved to be more potent than any of the 3 folate-DNP conjugates. We conclude that both folate-TNP and folate-FITC constitute promising haptens for use in FR-targeted immunotherapy of arthritis.

Original languageEnglish (US)
Pages (from-to)1228-1236
Number of pages9
JournalMolecular pharmaceutics
Issue number4
StatePublished - Aug 3 2009


  • Activated macrophages
  • Arthritis
  • Dinitrophenyl
  • Drug-targeting
  • Fluorescein
  • Folate receptor
  • Immunotherapy
  • Trinitrophenyl

ASJC Scopus subject areas

  • Pharmaceutical Science
  • Molecular Medicine
  • Drug Discovery


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