Dendritic cell cutaneous egression in Mycobacterium ulcerans infection

Buruli ulcer (a.k.a. Bairnsdale ulcer) is a chronic debilitating disease caused by Mycobacterium ulcerans, and is the third most prevalent mycobacterial disease in humans after tuberculosis and leprosy. It is prevalent in Africa, South America, the Western Pacific and interestingly has a growing prevalence in Australia. Although 70% of Buruli ulcers worldwide occur in children under 15 years of age, it occurs in an elder population in Australia.

Mycobacterium ulcerans infection is associated with production of a toxin, named mycolactone. This agent suppresses the normal immune responses including the normal function of dendritic cells. Dendritic cells normally function as antigen presenting cells, travelling to regional lymph nodes and inducing clonal proliferation. In M. ulcerans infection this does not occur: instead large numbers of dendritic cells are seen in the epidermis superficial to the zone of infection and appear to be shed along with keratinised squamous epithelial cells. By altering local immune responses required for normal skin healing, M. ulcerans causes destructive chronic skin ulcers, wounds in subcutaneous tissue and sometimes to bone, requiring extensive surgical excision and complex wound healing regimens that pose a heavy health burden on the patient, the community and the health care system.

Tissue sections from some 200+ Mycobacterium ulcerans surgical specimens are available for review. This pathophysiological process does not appear to have been described and review of the presently available material should result in a publication. The project is well suited to a self-motivated honours student with experience in histopathology or related sciences.

https://www.theage.com.au/national/victoria/stigma-isolation-the-flesh-eating-ulcer-infecting-hundreds-more-victorians-each-year-20190709-p525h4.html