Poultry Science Study Points to Specific Immune Activities Preventing Vitiligo

The Problem

Vitiligo, pronounced vit-ih-LIE-go, is an autoimmune disease characterized by the immune system attacking skin cells called melanocytes. It creates white patches of skin on the body because the pigment is deteriorated. The condition can also affect the eyes, causing blurred vision, and the inner ear, leading to hearing loss. Autoimmune diseases are often associated with other autoimmune disorders. For example, vitiligo is strongly associated with autoimmune thyroiditis in humans, which causes the thyroid gland to become attacked by the immune system.

The Work

Using a combination of flow cytometry and gene expression analyses, Erf and her team of researchers sought to gain a comprehensive understanding of the initiating events leading to expression of vitiligo in growing feathers by monitoring the infiltration of leukocytes and concurrent immunological activities in the target tissue beginning prior to visual onset and continuing throughout disease development.

She studies the disease using a rare vitiligo-prone chicken breed called the Smyth line, the only animal model for vitiligo that shares all the characteristics of the human condition. She compared test reactions in the vitiligo-susceptible Brown line, a parental line with similar genetics.

Erf has worked with the Smyth line since 1989 and maintains the only known research breeding flock in the world. Based on studying the autoimmune response in the feather pulp, Erf developed the tissue as a skin test-site — a “living test-tube,” she calls it — and a minimally invasive procedure to study immune responses to injected vaccines and other antigens. She has patented this method.

The Results

In the Smyth line, approximately one month before vitiligo becomes visible, an increase in the expression of specific immune regulatory genes was observed. Erf’s studies have shown that this early immune activity might play a role in triggering the disease. Overall, their findings align with observations in human studies, with the added benefit of new insights into events before the onset of the disease.

Examining growing feathers from the Brown line revealed immune cells entering the pulp, but these cells exhibited anti-inflammatory immune activities, which may be responsible for preventing vitiligo development in these chickens. The researchers also detected positive correlations that indicate an immune response with regulatory T cells, which stop vitiligo development and killing of the melanocytes.

The Value

Erf’s research suggests the different responses in Smyth and Brown line chickens could lead to new ways of understanding how the immune system decides between attacking or tolerating melanocytes, which could lead to significant advancements in treatment of autoimmune diseases like vitiligo.