Hapten-Induced Contact Hypersensitivity, Autoimmune Reactions, and Tumor Regression: Plausibility of Mediating Antitumor Immunity

Abstract

Haptens are small molecule irritants that bind to proteins and elicit an immune response. Haptens have been commonly used to study allergic contact dermatitis (ACD) using animal contact hypersensitivity (CHS) models. However, extensive research into contact hypersensitivity has offered a confusing and intriguing mechanism of allergic reactions occurring in the skin. The abilities of haptens to induce such reactions have been frequently utilized to study the mechanisms of inflammatory bowel disease (IBD) to induce autoimmune-like responses such as autoimmune hemolytic anemia and to elicit viral wart and tumor regression. Hapten-induced tumor regression has been studied since the mid-1900s and relies on four major concepts: (1) ex vivo haptenation, (2) in situ haptenation, (3) epifocal hapten application, and (4) antigen-hapten conjugate injection. Each of these approaches elicits unique responses in mice and humans. The present review attempts to provide a critical appraisal of the hapten-mediated tumor treatments and offers insights for future development of the field.

Diphenylcyclopropenone for the treatment of cutaneous in‐transit melanoma metastases – results of a prospective, non‐randomized, single‐centre study

“…demonstrated the involvement of TH17 lymphocytes in the immunomodulatory mechanism observed in DPCP‐induced regression of cutaneous melanoma metastases. The DPCP‐induced adaptive immune response likely stems from a local hypersensitivity reaction with epifocal haptenation favouring CD8 + T‐lymphocyte activation …”

Regulation of contact sensitivity in non‐obese diabetic (NOD) mice by innate immunity

“…Genetic factors play an important role in skin immune responses, including CHS. Recent studies have suggested that autoimmunity contributes to susceptibility to allergies, including skin allergy . The genetic background of the non‐obese diabetic (NOD) mouse includes multiple autoimmune susceptibility loci .…”

Indigo Naturalis Ameliorates Oxazolone-Induced Dermatitis but Aggravates Colitis by Changing the Composition of Gut Microflora

“…Therefore, to investigate the effect of IND, we selected OXA to create animal models of inflammation. OXA is a haptenating agent that has been used to induce both allergic dermatitis [19,20] and Th2 type colitis, with bowel wall edema and luminal exudates, that is more reminiscent of UC than of Crohn's disease [21]. …”