Expression and production of the SERPING1-encoded endogenous complement regulator C1-inhibitor in multiple cohorts of tuberculosis patients.

BACKGROUND: To facilitate better discrimination between patients with active tuberculosis (TB) and latent TB infection (LTBI), whole blood transcriptomic studies have been performed to identify novel candidate host biomarkers. SERPING1, which encodes C1-inhibitor (C1-INH), the natural inhibitor of the C1-complex has emerged as candidate biomarker. Here we collated and analysed SERPING1 expression data and subsequently determined C1-INH protein levels in four cohorts of patients with TB. METHODS: SERPING1 expression data were extracted from online deposited datasets. C1-INH protein levels were determined by ELISA in sera from individuals with active TB, LTBI as well as other disease controls in geographically diverse cohorts. FINDINGS: SERPING1 expression was increased in patients with active TB compared to healthy controls (8/11 cohorts), LTBI (13/14 cohorts) and patients with other (non-TB) lung-diseases (7/7 cohorts). Serum levels of C1-INH were significantly increased in The Gambia and Italy in patients with active TB relative to the endemic controls but not in South Africa or Korea. In the largest cohort (n = 50), with samples collected longitudinally, normalization of C1-INH levels following successful TB treatment was observed. This cohort, also showed the most abundant increase in C1-INH, and a positive correlation between C1q and C1-INH levels. Combined presence of increased levels of both C1q and C1-INH had high specificity for active TB (96 %) but only very modest sensitivity 38 % compared to the endemic controls. INTERPRETATION: SERPING1 transcript expression is increased in TB patients, while serum protein levels of C1-INH were increased in half of the cohorts analysed

Expression and production of the SERPING1-encoded endogenous complement regulator C1-inhibitor in multiple cohorts of tuberculosis patients

CITATION: Lubbers, R. et al. 2020. Expression and production of the SERPING1-encoded endogenous complement regulator C1-inhibitor in multiple cohorts of tuberculosis patients. Molecular Immunology, 120:187–195, doi:10.1016/j.molimm.2020.02.006.The original publication is available at https://www.sciencedirect.comBackground To facilitate better discrimination between patients with active tuberculosis (TB) and latent TB infection (LTBI), whole blood transcriptomic studies have been performed to identify novel candidate host biomarkers. SERPING1, which encodes C1-inhibitor (C1-INH), the natural inhibitor of the C1-complex has emerged as candidate biomarker. Here we collated and analysed SERPING1 expression data and subsequently determined C1-INH protein levels in four cohorts of patients with TB. Methods SERPING1 expression data were extracted from online deposited datasets. C1-INH protein levels were determined by ELISA in sera from individuals with active TB, LTBI as well as other disease controls in geographically diverse cohorts. Findings SERPING1 expression was increased in patients with active TB compared to healthy controls (8/11 cohorts), LTBI (13/14 cohorts) and patients with other (non-TB) lung-diseases (7/7 cohorts). Serum levels of C1-INH were significantly increased in The Gambia and Italy in patients with active TB relative to the endemic controls but not in South Africa or Korea. In the largest cohort (n = 50), with samples collected longitudinally, normalization of C1-INH levels following successful TB treatment was observed. This cohort, also showed the most abundant increase in C1-INH, and a positive correlation between C1q and C1-INH levels. Combined presence of increased levels of both C1q and C1-INH had high specificity for active TB (96 %) but only very modest sensitivity 38 % compared to the endemic controls. Interpretation SERPING1 transcript expression is increased in TB patients, while serum protein levels of C1-INH were increased in half of the cohorts analysed.Publisher's versio

Complement Component C1q as Serum Biomarker to Detect Active Tuberculosis.

Background: Tuberculosis (TB) remains a major threat to global health. Currently, diagnosis of active TB is hampered by the lack of specific biomarkers that discriminate active TB disease from other (lung) diseases or latent TB infection (LTBI). Integrated human gene expression results have shown that genes encoding complement components, in particular different C1q chains, were expressed at higher levels in active TB compared to LTBI. Methods: C1q protein levels were determined using ELISA in sera from patients, from geographically distinct populations, with active TB, LTBI as well as disease controls. Results: Serum levels of C1q were increased in active TB compared to LTBI in four independent cohorts with an AUC of 0.77 [0.70; 0.83]. After 6 months of TB treatment, levels of C1q were similar to those of endemic controls, indicating an association with disease rather than individual genetic predisposition. Importantly, C1q levels in sera of TB patients were significantly higher as compared to patients with sarcoidosis or pneumonia, clinically important differential diagnoses. Moreover, exposure to other mycobacteria, such as Mycobacterium leprae (leprosy patients) or BCG (vaccinees) did not result in elevated levels of serum C1q. In agreement with the human data, in non-human primates challenged with Mycobacterium tuberculosis, increased serum C1q levels were detected in animals that developed progressive disease, not in those that controlled the infection. Conclusions: In summary, C1q levels are elevated in patients with active TB compared to LTBI in four independent cohorts. Furthermore, C1q levels from patients with TB were also elevated compared to patients with sarcoidosis, leprosy and pneumonia. Additionally, also in NHP we observed increased C1q levels in animals with active progressive TB, both in serum and in broncho-alveolar lavage. Therefore, we propose that the addition of C1q to current biomarker panels may provide added value in the diagnosis of active TB

Effect of amino acid substitutions in the human IFN-gamma R2 on IFN-gamma responsiveness

Patients with interferon-gamma receptor (IFN-gamma R) null mutations have severe infections with poorly pathogenic Mycobacteria. The IFN-gamma R complex involves two IFN-gamma R1 and two IFN-gamma R2 chains, in which several amino acid substitutions, some linked to disease and some apparently naturally occurring, have been described. We developed a model system to study functional effects of genetic variations in IFN-gamma R2. We retrovirally transduced wild-type IFN-gamma R2 and IFN-gamma R2 carrying presently known amino acid substitutions in various human cell lines, and next determined the IFN-gamma R2 expression pattern as well as IFN-gamma responsiveness. We determined that the T58R, Q64R, E147K and K182E variants of IFN-gamma R2 are fully functional, although the Q64R variant may be expressed higher on the cell membrane. The R114C, T168N and G227R variants were identified in patients that had disseminated infections with non-tuberculous Mycobacteria. Of these genetic variants, T168N was confirmed to be completely non-functional, whereas the novel variant G227R, and the previously reported R114C, were partial functional. The impaired IFN-gamma responsiveness of R114C and G227R is mainly due to reduced receptor function, although expression on the cell membrane is reduced as well. We conclude that the T58R, Q64R, E147K and K182E variants are polymorphisms, whereas the R114C, T168N and G227R constitute mutations associated with disease

Differential expression and function of human IL-12Rβ2 polymorphic variants

Immunogenetics and cellular immunology of bacterial infectious disease

Disseminated Mycobacterium genavense infection in a patient with a novel partial interleukin-12/23 receptor β1 deficiency

A patient presented with late onset disseminated nontuberculous mycobacterium (NTM) infection due to a novel interleukin-12/interleukin-23 receptor beta1 (IL-12/IL-23Rbeta1) mutation, r.1561C>G, leading to the amino acid substitution R521G. This is the second patient reported with a partial IL-12/IL-23Rbeta1 defect

Salmonella induced IL-23 and IL-1beta allow for IL-12 production by monocytes and Mphi1 through induction of IFN-gamma in CD56 NK/NK-like T cells.

BACKGROUND:The type-1 cytokine pathway plays a pivotal role in immunity against intracellular bacterial pathogens such as Salmonellae and Mycobacteria. Bacterial stimulation of pattern recognition receptors on monocytes, macrophages and dendritic cells initiates this pathway, and results in the production of cytokines that activate lymphocytes to produce interferon (IFN)-gamma. Interleukin (IL)-12 and IL-23 are thought to be the key cytokines required for initiating a type-1 cytokine immune response to Mycobacteria and Salmonellae. The relative contribution of IL-23 and IL-12 to this process is uncertain. METHODOLOGY/PRINCIPAL FINDINGS:We show that various TLR agonists induce the production of IL-23 but not IL-12 in freshly isolated human monocytes and cultured human macrophages. In addition, type 1 pro-inflammatory macrophages (Mphi1) differentiated in the presence of GM-CSF and infected with live Salmonella produce IL-23, IL-1beta and IL-18, but not IL-12. Supernatants of Salmonella-infected Mphi1 contained more IL-18 and IL-1beta as compared with supernatants of Mphi1 stimulated with isolated TLR agonists, and induced IFN-gamma production in human CD56(+) cells in an IL-23 and IL-1beta-dependent but IL-12-independent manner. In addition, IL-23 together with IL-18 or IL-1beta led to the production of GM-CSF in CD56(+) cells. Both IFN-gamma and GM-CSF enhanced IL-23 production by monocytes in response to TLR agonists, as well as induced IL-12 production. CONCLUSIONS/SIGNIFICANCE:The findings implicate a positive feedback loop in which IL-23 can enhance its release via induction of IFN-gamma and GM-CSF. The IL-23 induced cytokines allow for the subsequent production of IL-12 and amplify the IFN-gamma production in the type-1 cytokine pathway

Severe disseminated mycobacterial infection in a boy with a novel mutation leading to IFN-gamma R2 deficiency

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare syndrome characterized by predisposition to severe, sometimes lethal, disease caused by otherwise poorly virulent mycobacteria. We report here a boy with a recurrent mycobacterial infection from the age of five months. Immunological analyses revealed an inability to respond to IFN-gamma, subsequent genetic analyses revealed a novel homozygous mutation, r.679G > A in the IFNGR2 gene, resulting in a G227R substitution, that caused IFN-gamma R2 deficiency. This is only the 8th mutation in IFN-gamma R2 known so far. The boy eventually died of hepatic coma due to liver failure at the age of five

Inhibition of the type I immune responses of human monocytes by IFN-α and IFN-β

Experimental cancer immunology and therap