Sumary of Cell-analysis technique could combat tuberculosis:
- A new method that analyzes how individual immune cells react to the bacteria that cause tuberculosis could pave the way for new vaccine strategies against this deadly disease, and provide insights into fighting other infectious diseases around the world.
- and single-cell RNA sequencing (scRNA-seq), which yields RNA transcripts of individual host macrophage cells.
- After infecting mice with the fluorescent reporter Mtb bacteria, Russell’s team was able to gather and flow-sort individual Mtb-infected macrophages from the mouse lung.
- The researchers then determined which macrophages promoted Mtb growth (sporting happy, red-glowing bacteria) or contained stressed Mtb unlikely to grow (unhappy, green-glowing bacteria).
- Next, they took the two sorted, infected macrophage populations and ran them through single-cell RNA sequencing analysis, thereby generating transcriptional profiles of each individual host cell in both populations.
- When the scientists compared the macrophage single cell sequencing data with the reporter bacteria phenotype, they found an almost perfect one-to-one correlation between the fitness status of the bacterium and the transcriptional profile in the host cell.
- Macrophages that housed unhappy green bacteria also expressed genes that were known to discourage bacterial growth, while those with happy red bacteria expressed genes known to promote bacterial growth.
- “While our previous results identifying the resident alveolar macrophages (AM) as permissive and the blood monocyte-derived recruited macrophages (IM) as controlling Mtb infection was correct in a broad sense, we found, unsurprisingly, that this was an oversimplification,” Russell said.