Activation and Regulation of Blood Vδ2 T Cells Are Amplified by TREM-1+ during Active Pulmonary Tuberculosis.

Triggering receptor expressed on myeloid cells 1 (TREM-1) is a receptor mainly expressed on myeloid cells, and it plays an important role in modulating immune response against infectious agents. The function of TREM-1 on nonmyeloid cells such as Vδ2 T cells has not been characterized, and their role in pulmonary tuberculosis (TB) remains unclear. To assess the expression of TREM-1 on blood Vδ2 T cells from pulmonary TB patients and investigate its mechanism of induction, we exploited flow cytometry analysis to study the expression of TREM-1 on Vδ2 T cells from active pulmonary TB patients and control subjects. In this study we demonstrate that TREM-1 (TREM-1+) is highly expressed on Vδ2 T cells of patients with active pulmonary TB. Unlike TREM-1--expressing Vδ2 T cells, TREM-1+-producing Vδ2 T cells display APC-like phenotypes. Surprisingly, TREM-1+ signaling promotes the Ag-presenting capability of Vδ2 T cells to induce the CD4+ T cell response. TREM-1+Vδ2 T cells induced the proliferation and differentiation of naive CD4+ T cells, as well as the elimination of intracellular mycobacteria. We identified TREM-1+ (but not TREM-1-) as an Ag-presentation amplifier on human blood Vδ2 T cells, and data shed new light on the regulation of Vδ2 T cells in the phase of innate and adaptive immune responses against Mycobacterium tuberculosis infection. Targeting TREM-1+Vδ2 T cells may be a promising approach for TB therapy.

Efficacy and safety of concurrent anti-tuberculosis treatment and chemotherapy in lung cancer patients with co-existent tuberculosis.

BACKGROUND: This retrospective study evaluated the safety and efficacy of concurrent anti-tuberculosis (TB) and chemotherapy treatment in patients with advanced lung cancer and active TB. METHODS: We retrospectively analyzed patients who were first diagnosed with advanced lung cancer and received first-line chemotherapy in Guangzhou Chest Hospital from 2015 to 2017. Patients were categorized into two groups (2:1): lung cancer patients without active TB (Group A), and lung cancer patients with active TB (Group B). Primary endpoints included adverse events (AEs), objective response rate (ORR), time to treatment failure, and overall survival (OS). RESULTS: A total of 99 patients were eligible (Group A, n=66; Group B, n=33). Grade ≥3 treatment-related AEs, primarily hematologic toxicity, occurred in 39.4% and 51.5% of patients in Groups A and B, respectively. The hypohepatia in both groups was generally at grade 1 or 2, with similar incidences (26% and 27%, respectively). After two cycles of chemotherapy, the ORR was 42.4% and 33.3% in Group A and B, respectively (P=0.383). The median time to treatment failure (TTF) was 7.0 and 5.6 months for Groups A and B, respectively (P=0.175). The median OS was 17.0 and 14.0 months for Groups A and B, respectively (P=0.312). After 3 months of anti-TB treatment, all patients achieved sputum acid-fast bacilli (AFB) smear conversion and absorption on imaging, and the end of follow-up observed no recurrence. CONCLUSIONS: Concurrent anti-TB and chemotherapy treatment did not increase hematological toxicity or hypohepatia in lung cancer patients with pulmonary TB.

[Association between HLA-A and HLA-DRB1 allele polymorphisms and susceptibility to tuberculosis in southern Chinese population].

OBJECTIVE: To study the relationship between HLA allele frequencies in peripheral blood mononuclear cells (PBMCs) and the susceptibility to tuberculosis in southern Chinese population. METHODS: The polymorphisms of HLA-A and HLA-DRB1 loci in the PBMCs were analyzed in 294 patients with active tuberculosis using polymerase chain reaction-sequence based typing (PCT-SBT). The allele frequencies in the patients were compared with the data from 644 control southern Chinese subjects obtained from the online database Allele Frequencies in Worldwide Population. RESULTS: The frequencies of HLA-A* 0101 and HLA-DRB1*1454 alleles in the patient cohort with pulmonary tuberculosis were significantly higher than those in the control group (2.4% vs 0.6%, χ2=10.788, P=0.001, Pc=0.016; 7.5% vs 0%, χ2=69.850, P < 0.0001); the frequencies of HLA-DRB1*1202 and HLA-DRB1*1401 alleles were significantly lower in this patient cohort than in the control group (10.4% vs 16.1%, χ2=9.845, P=0.002, Pc=0.044; 0% vs 3.1%, χ2=18.520, P < 0.001). CONCLUSIONS: The frequencies of HLA-A and HLA-DRB1 alleles are correlated with the susceptibility to active tuberculosis in this southern Chinese population. HLA-A*0101, HLA-DRB1*1454 and the other 3 alleles are likely susceptible genes to tuberculosis, while HLA-DRB1*1202, HLA-DRB1*1401 and the other 4 alleles can be protective genes in this population.

IFN-γ differentially regulates subsets of Gr-1(+)CD11b(+) myeloid cells in chronic inflammation.

During chronic inflammation, prolonged over-reactive immune response may lead to tissue destruction, while immune suppression hinders tissue repair and pathogen elimination. Therefore, precise regulation of the immune response is needed to avoid immuno-pathology. Interferon-gamma (IFN-γ) is widely used in clinical treatment of inflammatory diseases. However, the underlying mechanism remains unclear. Here, we evaluated the role of IFN-γ on CD11b(+)Gr-1(+) myeloid cell differentiation and function, using a heat-killed Mycobacterium bovis BCG-induced chronic inflammation model. After challenge with heat-killed BCG, two subpopulations of CD11b(+)Gr-1(+) myeloid cells were generated in the mouse spleen. Phenotypical, morphological and functional analysis indicated that the CD11b(+)Gr-1(high) Ly6G(high) Ly6C(low) subset was neutrophil-like myeloid-derived inducer cells (N-MDICs), which promoted T cell activation, while the other subset was CD11b(+)Gr-1(low) Ly6G(neg) Ly6C(high) monocyte-like myeloid-derived suppressor cells (M-MDSCs) that displayed extensive suppressor function. IFN-γ treatment dampened N-MDICs-mediated T cell activation through up-regulating T cell suppressive mediators, reactive oxygen species (ROS) and arginase I. While for M-MDSCs, IFN-γ reduced their suppressing activity by decreasing the arginase activity. Our study provides evidence that IFN-γ balances the over-reactive vs compromised immune response through different regulation of distinct myeloid subsets, and therefore displays significant therapeutic potential for effective immuno-therapy of chronic inflammatory diseases.