Rationale: Among patients with nontuberculous mycobacterial lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. We hypothesize that unidentified factors predispose these individuals to pulmonary nontuberculous mycobacterial disease. Objectives: To compare body morphotype, serum adipokine levels, and whole-blood cytokine responses of patients with pulmonary nontuberculous mycobacteria (pNTM) with contemporary control subjects who are well matched demographically. Methods: We enrolled 103 patients with pNTM and 101 uninfected control subjects of similar demographics. Body mass index and body fat were quantified. All patients with pNTM and a subset of control subjects were evaluated for scoliosis and pectus excavatum. Serum leptin and adiponectin were measured. Specific cytokines important to host-defense against mycobacteria were measured in whole blood before and after stimulation. Measurements and Main Results: Patients with pNTM and control subjects were well matched for age, gender, and race. Patients with pNTM had significantly lower body mass index and body fat and were significantly taller than control subjects. Scoliosis and pectus excavatum were significantly more prevalent in patients with pNTM. The normal relationships between the adipokines and body fat were lost in the patients with pNTM, a novel finding. IFN-g and IL-10 levels were significantly suppressed in stimulated whole blood of patients with pNTM. Conclusions: This is the first study to comprehensively compare body morphotype, adipokines, and cytokine responses between patients with NTM lung disease and demographically matched controls. Our findings suggest a novel, predisposing immunophenotype that should be mechanistically defined.Keywords: leptin; adiponectin; pectus excavatum; scoliosis; Marfan syndrome Chronic lung disease due to nontuberculous mycobacteria (NTM) is a growing public health concern (1-3). Recent studies estimate the incidence in the United States to be five to six cases per 100,000 and as high as 15.5 cases per 100,000 in persons over 50 years of age (3-5). Because the duration of symptomatic NTM lung disease is often years, the prevalence of disease is estimated to be 10 to 40 cases per 100,000 (1).In the United States, the most common NTM species associated with lung disease are Mycobacterium avium complex (MAC), Mycobacterium kansasii, and Mycobacterium abscessus. Although NTM are widespread in water and soil (6, 7), relatively few persons develop disease. Thus, intact immunity is likely pivotal for protection against NTM.Chronic lung disease is the most common form of NTM infection, manifested by two main radiographic patterns: (i) an upper lobe fibrocavitary pattern that occurs mostly in men with underlying lung disease such as chronic obstructive pulmonary disease (COPD) and (ii) a nodular-bronchiectasis pattern that often involves the right middle lobe and lingula and which appears to be more common in women with no clear risk factors (8)...

IL-32, a proinflammatory cytokine that activates the p38MAPK and NF-κB pathways, induces other cytokines, for example, IL-1β, IL-6, and TNF-α. This study investigated the role of endogenous IL-32 in HIV-1 infection by reducing IL-32 with small interfering (si)RNA in freshly infected PBMC and in the latently infected U1 macrophage cell line. When PBMC were pretreated with siRNA to IL-32 (siIL-32), IL-6, IFN-γ, and TNF-α were reduced by 57, 51, and 36%, respectively, compared with scrambled siRNA. Cotransfection of NF-κB and AP-1 reporter constructs with siIL-32 decreased DNA binding of these transcription factors by 42 and 46%, respectively. Cytokine protein array analysis revealed that the inhibitory activity of siIL-32 primarily targeted Th1 and proinflammatory cytokines and chemokines, e.g., MIP-1α/β. Unexpectedly, HIV-1 production (as measured by p24) increased 4-fold in these same PBMC when endogenous IL-32 was reduced. Because IFN-γ was lower in siIL-32-treated PBMC, we blocked IFN-γ bioactivity, which enhanced the augmentation of p24 by siIL-32. Furthermore, siIL-32 reduced the natural ligands of the HIV-1 coreceptors CCR5 (MIP-1α/β and RANTES) and CXCR4 (SDF-1). Inhibition of endogenous IL-32 in U1 macrophages also increased HIV-1. When rhIL-32γ was added to these cells, p24 levels fell by 72%; however, in the same cultures IFN-α increased 4-fold. Blockade of IFN-α/β bioactivity in IL-32γ-stimulated U1 cells revealed that IFN-α conveys the anti-HIV-1 effect of rhIL-32γ. In summary, depletion of endogenous IL-32 reduced the levels of Th1 and proinflammatory cytokines but paradoxically increased p24, proposing IL-32 as a natural inhibitor of HIV-1.

Several observations suggest endogenous suppressors of inflammatory mediators are present in human blood. alpha-1-Antitrypsin (AAT) is the most abundant serine protease inhibitor in blood, and AAT possesses anti-inflammatory activity in vitro and in vivo. Here, we show that in vitro stimulation of whole blood from persons with a genetic AAT deficiency resulted in enhanced cytokine production compared with blood from healthy subjects. Using whole blood from healthy subjects, dilution of blood with RPMI tissue-culture medium, followed by incubation for 18 h, increased spontaneous production of IL-8, TNF-alpha, IL-1 beta, and IL-1R antagonist (IL-1Ra) significantly, compared with undiluted blood. Dilution-induced cytokine production suggested the presence of one or more circulating inhibitors of cytokine synthesis present in blood. Serially diluting blood with tissue-culture medium in the presence of cytokine stimulation with heat-killed Staphylococcus epidermidis (S. epi) resulted in 1.2- to 55-fold increases in cytokine production compared with S. epi stimulation alone. Diluting blood with autologous plasma did not increase the production of IL-8, TNF-alpha, IL-1 beta, or IL-1Ra, suggesting that the endogenous, inhibitory activity of blood resided in plasma. In whole blood, diluted and stimulated with S. epi, exogenous AAT inhibited IL-8, IL-6, TNF-alpha, and IL-1 beta significantly but did not suppress induction of the anti-inflammatory cytokines IL-1Ra and IL-10. These ex vivo and in vitro observations suggest that endogenous AAT in blood contributes to the suppression of proinflammatory cytokine synthesis.

Several observations suggest the existence of potent endogenous suppressors of human immunodeficiency virus type 1 (HIV-1) production, and inhibitors of serine proteases may participate in this effect. Alpha-1-antitrypsin (AAT) is the most abundant circulating serine protease inhibitor. Physiological AAT concentrations inhibited HIV-1 production in chronically infected U1 monocytic cells, reduced virus replication in freshly infected peripheral blood mononuclear cells, and blocked infection of permissive HeLa cells. In U1 cells, AAT suppressed activation of the HIV-1-inducing transcription factor NF-kappaB. Similar results were obtained using CE-2072, a synthetic inhibitor of host serine proteases. HIV-1 did not replicate in blood obtained from healthy volunteers, but marked replication was observed in blood from individuals with hereditary AAT deficiency. These results identify AAT as a candidate circulating HIV-1 inhibitor in vivo. Two different mechanisms of AAT-induced HIV-1 inhibition were identified, including reduced HIV-1 infectivity and blockade of HIV-1 production. A novel host-pathogen interaction is suggested, and an alternative strategy to treat HIV-1-related disease may be possible.