Protection against reinfection with Mycobacterium tuberculosis extends across heterologous Mtb lineages

Indonesian cynomolgus macaques were infected with a genetically barcoded library of Mtb Erdman strain (a lineage 4 strain, ErdL4). This infection was then cleared with anti-TB antibiotics, HRZE, and then followed by a secondary exposure to a barcoded HTL2 strain (aka L2 G2GPeru8165). This group is referred to as ErdmanG2G. A parallel, Mtb-naive group was infected with HT-L2 to compare disease outcomes without pre-existing immunity, and referred to as the G2G group. Our results demonstrate that L4-induced immunity is capable of limiting infection and disease following subsequent exposure to HTL2. Thus, there is cross-lineage protection induced by Mtb.