Tuberculosis (TB) is one the most prevalent infectious diseases in the world, but only 10% of infected individuals develop active TB. One of the most important challenges in TB control is to be able to distinguish between patients with latent TB from those with active TB. During TB infection, macrophage aggregates, known as granulomas, form in the lungs to promote macrophage activation and help control TB infection. The formation of granulomas is associated with latent TB, while an absence of granulomas is a characteristic of active TB infection. Using both human and experimental models of TB infection, Slight et al. evaluated the role of CXCR5+ T cells in immune control. Here they show a section of formalin-fixed, paraffin-embedded lung biopsy from a patient with active TB. The sections were analyzed by immunofluorescence using antibodies specific to CD20 (white), IgD (green), and PCNA (red). Additionally, the section was counterstained with DAPI (DNA, blue). These markers indicate the presence of antibody-generating B cells. Slight and colleagues found that the presence of CXCR5+ T cells in lung granulomas were associated with immune control and play a protective role during TB infection.
One third of the world’s population is infected with
Samantha R. Slight, Javier Rangel-Moreno, Radha Gopal, Yinyao Lin, Beth A. Fallert Junecko, Smriti Mehra, Moises Selman, Enrique Becerril-Villanueva, Javier Baquera-Heredia, Lenin Pavon, Deepak Kaushal, Todd A. Reinhart, Troy D. Randall, Shabaana A. Khader