NeutroTB study highlights potential unique phenotypes of neutrophils

Dr Elouise Elizabeth Kroon was awarded a Doctor of Philosophy degree for her dissertation entitled ‘Neutrophils as effector cells in resistance to infection by Mycobacterium tuberculosis in HIV-infected individuals’ by the Faculty of Medicine and Health Sciences at Stellenbosch University in April 2022.

The PhD study is one of the major aims of the NeutroTB project. Dr Kroon, who is also a clinician, identified persons, living with HIV in high TB prevalence communities, who do not show immune conversion to tests used to infer Mycobacterium tuberculosis (Mtb) infection, nor had previous or current TB. This phenotype has been defined as HIV-1-positive persistently TB, tuberculin and IGRA negative (HITTIN). For NeutroTB and the PhD she explored gene expression differences between Mtb infection responses in neutrophils from HITTIN compared to neutrophils from persons with so-called latent Mtb infection using bulk RNA sequencing. Neutrophils from HITTIN show significant differences after 6 hours of infection with Mtb, with key pathways controlling cell death inflammation that were highlighted. Further functional validation is currently underway.

The NeutroTB study was supported by a Career Development Fellowship (TMA2018CDF-2353) and a Clinician Researcher M.D PhD Scholarship in Clinical/Health Research from the SAMRC.