Trans-vivo delayed type hypersensitivity assay for antigen specific regulation

Area of Science:

• Immunology
• Transplantation immunology
• Cellular immunology

Background:

• Delayed-type hypersensitivity (DTH) is a T cell-mediated immune response to antigens.
• Traditional DTH assays are useful for diagnosing infections but not feasible for transplant patients due to sensitization risks.
• An alternative, the trans-vivo DTH (Tv-DTH) assay, was developed to overcome these limitations.

Purpose of the Study:

• To describe the trans-vivo delayed-type hypersensitivity (Tv-DTH) assay.
• To highlight its application in assessing transplant recipient immune status towards donor antigens.
• To explore its utility in detecting regulatory T cells and guiding immunosuppression strategies.

Main Methods:

• The Tv-DTH assay involves injecting human peripheral blood mononuclear cells (PBMCs) and specific antigens into mice.
• DTH-like swelling is measured 18-24 hours post-injection, indicating an antigen-specific immune response.
• Antigen presentation by human cells in mice triggers an inflammatory cascade and measurable swelling.

Main Results:

• A positive donor-reactive DTH response in the Tv-DTH assay signifies a pro-inflammatory immune disposition toward graft alloantigens.
• The assay can detect regulatory T cells, which induce bystander suppression, a characteristic of accepted allografts.
• This monitoring may identify transplant recipients suitable for reduced immunosuppression.

Conclusions:

• The Tv-DTH assay is a valuable tool for assessing transplant recipient alloreactivity and immune regulation.
• It offers potential for personalized immunosuppression management, reducing risks of rejection and renal dysfunction.
• Emerging applications include monitoring autoimmunity and tumor immunology.