Talaromyces marneffei infection associated with bronchiolitis obliterans in an HIV-negative child: a case report

Talaromyces marneffei infection with IFNGR1 gene mutation in a patient with negative Anti-Interferon-γ autoantibodies

BACKGROUND

Talaromyces Marneffei (TM) is a rare opportunistic pathogen that mostly infects patients with low immunity compared to those with normal immunity. It may be related to immune deficiency or genetic factors.

OBJECTIVE

To evaluate the gene mutation of a patient infected with TM in an endemic area with negative anti-interferon-γ autoantibodies, and negative human immunodeficiency virus (HIV) infection.

METHODS

Extract deoxyribonucleic acid (DNA) samples from the patient's peripheral blood, detect the mutation gene by whole exome sequencing (WES), and carry out Sanger sequencing verification for the detected mutation gene.

RESULTS

The authors detected a mutation in the IFNGR1 gene (NM_001363526.1) and validated the detected gene mutation using Sanger sequencing. The results showed a heterozygous mutation c.4C>T (p.L2F) located in the IFNGR1 gene (NM_001363526.1).

STUDY LIMITATIONS

The mechanism of the IFNGR1 gene has not been further investigated in this study.

CONCLUSIONS

The IFNGR1 gene mutation may be a potential risk factor for TM infection, and the presence of anti-interferon-γ autoantibodies can aggravate disease symptoms.

Heterozygous mutations in the C-terminal domain of COPA underlie a complex autoinflammatory syndrome

Mutations in the N-terminal WD40 domain of coatomer protein complex subunit α (COPA) cause a type I interferonopathy, typically characterized by alveolar hemorrhage, arthritis, and nephritis. We described 3 heterozygous mutations in the C-terminal domain (CTD) of COPA (p.C1013S, p.R1058C, and p.R1142X) in 6 children from 3 unrelated families with a similar syndrome of autoinflammation and autoimmunity. We showed that these CTD COPA mutations disrupt the integrity and the function of coat protein complex I (COPI). In COPAR1142X and COPAR1058C fibroblasts, we demonstrated that COPI dysfunction causes both an anterograde ER-to-Golgi and a retrograde Golgi-to-ER trafficking defect. The disturbed intracellular trafficking resulted in a cGAS/STING-dependent upregulation of the type I IFN signaling in patients and patient-derived cell lines, albeit through a distinct molecular mechanism in comparison with mutations in the WD40 domain of COPA. We showed that CTD COPA mutations induce an activation of ER stress and NF-κB signaling in patient-derived primary cell lines. These results demonstrate the importance of the integrity of the CTD of COPA for COPI function and homeostatic intracellular trafficking, essential to ER homeostasis. CTD COPA mutations result in disease by increased ER stress, disturbed intracellular transport, and increased proinflammatory signaling.