MPEG1/perforin-2 mutations in human pulmonary nontuberculous mycobacterial infections
Ryan M. McCormack, Eva P. Szymanski, Amy P. Hsu, Elena Perez, Kenneth N. Olivier, Eva Fisher, E. Brook Goodhew, Eckhard R. Podack, Steven M. Holland
Ryan M. McCormack, Eva P. Szymanski, Amy P. Hsu, Elena Perez, Kenneth N. Olivier, Eva Fisher, E. Brook Goodhew, Eckhard R. Podack, Steven M. Holland
View: Text | PDF
Research Article Genetics Infectious disease

MPEG1/perforin-2 mutations in human pulmonary nontuberculous mycobacterial infections

Abstract

Perforin-2 is a highly conserved pore-forming protein encoded by macrophage expressed gene 1 (MPEG1). A number of studies have shown that Perforin-2–deficient mice are unable to survive following a bacterial challenge that is nonlethal in WT mice. There is also recent evidence that Mpeg1+/– heterozygous mice display an intermediate killing ability compared with Mpeg1 WT and Mpeg1–/– mice. Despite these in vivo findings, to date, no perforin-2 deficiencies have been associated with human disease. Here, we report four patients with persistent nontuberculous mycobacterial infection who had heterozygous MPEG1 mutations. In vitro, neutrophils, macrophages, and B cells from these patients were unable to kill Mycobacterium avium as efficiently as normal controls. CRISPR mutagenesis validated the deleterious antibacterial activity of these mutations. These data suggest that perforin-2 haploinsufficiency may contribute to human susceptibility to infections with intracellular bacteria.

Authors

Ryan M. McCormack, Eva P. Szymanski, Amy P. Hsu, Elena Perez, Kenneth N. Olivier, Eva Fisher, E. Brook Goodhew, Eckhard R. Podack, Steven M. Holland

×

Figure 2

MPEG1-mutated EBV-transformed B cells, neutrophils, and monocyte-derived macrophages have impaired control of MAC in vitro.

Options: View larger image (or click on image) Download as PowerPoint
MPEG1-mutated EBV-transformed B cells, neutrophils, and monocyte-derived...
(A) Patient EBV-transformed B cell lines are unable to decrease Mycobacterium avium complex (MAC) CFU over time. In comparison, cell lines from age-matched controls show progressive inhibition of MAC CFU. Each time point consists of five biologic replicates and two technical replicates, and the experiment was repeated three times. This graph is representative of four experimental replicates. (B) Neutrophils from Patient 1 (p.T73A) do not inhibit MAC CFU as effectively as controls. (C) Monocyte-derived macrophages from Patient 1 do not inhibit MAC CFU as effectively as controls. Young control is 26 years old; age-matched control #1 is 57 years old; age-matched control #2 is 64 years old. B and C consist of five biologic replicates and three technical replicates. Graphs are representative of five experimental replicates. Statistical analysis was conducted with one-way ANOVA with Tukey post-hoc test. *P < 0.05. Detailed statistical breakdown is described in Supplemental Table 6.