Microbiology, Immunology, and Pathology

The completion of the genome sequences of Mycobacterium tuberculosis, M. leprae and other mycobacterial species has led to a greater understanding of host-pathogen interactions of these intracellular human pathogens. Although humans are considered the main host of M. leprae, research in our laboratory has contributed to findings that M. leprae has adapted to other mammalian species including red squirrels in the British Isles, armadillos in Brazil and Mexico and recently wild chimpanzees in Guinea-Bissau and Ivory Coast, West Africa, leading to speculation that M. leprae is capable of adapting to other animal or environmental reservoirs. Dr. Spencer spends up to 2-3 months a year working in the laboratory of Dr. Claudio Salgado in Marituba, Pará, Brazil on leprosy research and field surveillance activities with the support of two Fulbright Scholar to Brazil awards in 2015-2016 and 2019-2020.

Our research is focused on the following:

1. Understanding the humoral and cell-mediated immune responses to mycobacterial infection, mainly tuberculosis and leprosy.
2. Identifying biomarkers of infection detected by anti-PGL-I serology, cytokine/chemokine assays, metabolomics or by molecular means (PCR, microRNA).
3. Working with an international consortium of leprosy researchers in Brazil and the Netherlands to develop a simple lateral flow device that detects both antibody and cell-mediated responses to M. leprae antigens that can identify those asymptomatic individuals who are progressing towards disease.
4. Identifying novel M. leprae strain types and drug resistance markers circulating in human clinical isolates and animal species performed by post-doctoral researcher Dr. Charlotte Avanzi.

The overall goals of the above projects are geared towards the development of new diagnostic tools capable of diagnosing leprosy early prior to the development of nerve damage, disfigurement and disability, and identifying other environmental or animal reservoirs of this pathogen.