Tuberculosis is a significant global health threat, with one-third of the world's population infected with its causative agent Mycobacterium tuberculosis (Mtb). The emergence of multidrug-resistant (MDR) Mtb that is resistant to the frontline anti-tubercular drugs rifampicin and isoniazid forces treatment with toxic second-line drugs. Currently, ~4% of new and ~21% of previously treated tuberculosis cases are either rifampicin-drug-resistant or MDR Mtb infections. The specific molecular host-pathogen interactions mediating the rapid worldwide spread of MDR Mtb strains remain poorly understood. W-Beijing Mtb strains are highly prevalent throughout the world and associated with increased drug resistance. In the early 1990s, closely related MDR W-Beijing Mtb strains (W strains) were identified in large institutional outbreaks in New York City and caused high mortality rates. The production of interleukin-1β (IL-1β) by macrophages coincides with the shift towards aerobic glycolysis, a metabolic process that mediates protection against drug-susceptible Mtb. Here, using a collection of MDR W-Mtb strains, we demonstrate that the overexpression of Mtb cell wall lipids, phthiocerol dimycocerosates, bypasses the interleukin 1 receptor, type I (IL-1R1) signalling pathway, instead driving the induction of interferon-β (IFN-β) to reprogram macrophage metabolism. Importantly, Mtb carrying a drug resistance-conferring single nucleotide polymorphism in rpoB (H445Y) can modulate host macrophage metabolic reprogramming. These findings transform our mechanistic understanding of how emerging MDR Mtb strains may acquire drug resistance single nucleotide polymorphisms, thereby altering Mtb surface lipid expression and modulating host macrophage metabolic reprogramming.

NK cells are a promising cellular immunotherapy for cancer. Cytokine-induced memory-like (ML) NK cells differentiate after activation with IL-12, IL-15, and IL-18, exhibit potent anti-tumor responses, and safely induce complete remissions in patients with leukemia. However, many cancers are not fully recognized via NK cell receptors. Chimeric antigen receptors (CAR) have been utilized to enhance tumor-specific recognition by effector lymphocytes. We hypothesized that memory-like differentiation and CAR-engineering would result in complementary improvements in NK cell responses against NK-resistant cancers. To test this idea, peripheral blood ML NK cells were modified to express an anti-CD19 CAR (19-CAR-ML), which displayed significantly increased IFN-γ production, degranulation, and specific killing against NK-resistant lymphoma lines and primary targets, compared to non-specific control CAR-ML NK cells or conventional CAR NK cells. The 19-CAR and ML responses were synergistic, CAR-specific, and required ITAM signaling. Furthermore, 19-CAR-ML NK generated from lymphoma patients exhibited improved responses against their autologous lymphoma. 19-CAR-ML NK cells controlled lymphoma burden in vivo and improved survival in human xenograft models. Thus, CAR engineering of ML NK cells enhanced responses against resistant cancers and warrant further investigation, with the potential to broaden ML NK cell recognition against a variety of NK cell-resistant tumors.

ObjectivesHousehold contacts (HHCs) of pulmonary tuberculosis patients are at high risk of Mycobacterium tuberculosis infection and early disease development. Identification of individuals at risk of tuberculosis disease is a desirable goal for tuberculosis control. Interferon-gamma release assays (IGRAs) using specific M. tuberculosis antigens provide an alternative to tuberculin skin testing (TST) for infection detection. Additionally, the levels of IFNγ produced in response to these antigens may have prognostic value. We estimated the prevalence of M. tuberculosis infection by IGRA and TST in HHCs and their source population (SP), and assessed whether IFNγ levels in HHCs correlate with tuberculosis development.MethodsA cohort of 2060 HHCs was followed for 2–3 years after exposure to a tuberculosis case. Besides TST, IFNγ responses to mycobacterial antigens: CFP, CFP-10, HspX and Ag85A were assessed in 7-days whole blood cultures and compared to 766 individuals from the SP in Medellín, Colombia. Isoniazid prophylaxis was not offered to child contacts because Colombian tuberculosis regulations consider it only in children under 5 years, TST positive without BCG vaccination.ResultsUsing TST 65.9% of HHCs and 42.7% subjects from the SP were positive (OR 2.60, p<0.0001). IFNγ response to CFP-10, a biomarker of M. tuberculosis infection, tested positive in 66.3% HHCs and 24.3% from the SP (OR = 6.07, p<0.0001). Tuberculosis incidence rate was 7.0/1000 person years. Children <5 years accounted for 21.6% of incident cases. No significant difference was found between positive and negative IFNγ responders to CFP-10 (HR 1.82 95% CI 0.79–4.20 p = 0.16). However, a significant trend for tuberculosis development amongst high HHC IFNγ producers was observed (trend Log rank p = 0.007).DiscussionCFP-10-induced IFNγ production is useful to establish tuberculosis infection prevalence amongst HHC and identify those at highest risk of disease. The high tuberculosis incidence amongst children supports administration of chemoprohylaxis to child contacts regardless of BCG vaccination.

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Highlights d Induced Eomes deletion results in a rapid decrease in NK cell numbers d Eomes-deleted stage III NK cells exhibit increased apoptosis d Eomes-deleted stage II and III NK cells exhibit differentiation defects d Induced Eomes deletion compromises NK cytotoxicity and MHCI À/À rejection in vivo