Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an aberrant inflammatory response occurring in a subset of TB-HIV co-infected patients initiating anti-retroviral therapy (ART). Here, we examined monocyte activation by prospectively quantitating pro-inflammatory plasma markers and monocyte subsets in TB-HIV co-infected patients from a South Indian cohort at baseline and following ART initiation at the time of IRIS, or at equivalent time points in non-IRIS controls. Pro-inflammatory biomarkers of innate and myeloid cell activation were increased in plasma of IRIS patients pre-ART and at the time of IRIS; this association was confirmed in a second cohort in South Africa. Increased expression of these markers correlated with elevated antigen load as measured by higher sputum culture grade and shorter duration of anti-TB therapy. Phenotypic analysis revealed the frequency of CD14++CD16− monocytes was an independent predictor of TB-IRIS, and was closely associated with plasma levels of CRP, TNF, IL-6 and tissue factor during IRIS. In addition, production of inflammatory cytokines by monocytes was higher in IRIS patients compared to controls pre-ART. These data point to a major role of mycobacterial antigen load and myeloid cell hyperactivation in the pathogenesis of TB-IRIS, and implicate monocytes and monocyte-derived cytokines as potential targets for TB-IRIS prevention or treatment.

SUMMARYThe molecular chaperone Hsp90 protects deregulated signaling proteins that are vital for tumor growth and survival. Tumors generally display sensitivity and selectivity toward Hsp90 inhibitors; however, the molecular mechanism underlying this phenotype remains undefined. We report that the mitotic checkpoint kinase Mps1 phosphorylates a conserved threonine residue in the amino-domain of Hsp90. This, in turn, regulates chaperone function by reducing Hsp90 ATPase activity while fostering Hsp90 association with kinase clients, including Mps1. Phosphorylation of Hsp90 is also essential for the mitotic checkpoint because it confers Mps1 stability and activity. We identified Cdc14 as the phosphatase that dephosphorylates Hsp90 and disrupts its interaction with Mps1. This causes Mps1 degradation, thus providing a mechanism for its inactivation. Finally, Hsp90 phosphorylation sensitizes cells to its inhibitors, and elevated Mps1 levels confer renal cell carcinoma selectivity to Hsp90 drugs. Mps1 expression level can potentially serve as a predictive indicator of tumor response to Hsp90 inhibitors.

Paraffin sections of 247 primary and metastatic non-small cell lung carcinomas, the corresponding non-neoplastic lungs, and 75 other specimens were examined by immunohistochemical procedures using a panel of antibodies against the specific products of peripheral airway cells: the major surfactant-associated protein and 10-kD Clara cell protein. Non-small cell lung carcinoma tumors most frequently positive for either peripheral airway cell marker were adenocarcinomas (41%), especially those with papillolepidic growth pattern (56%), followed by large cell carcinomas (25%), other adenocarcinomas (22%), and squamous cell carcinomas (16%). Immunoreactivity was mainly focal and the expression of the two peripheral airway cell markers was discordant. The incidence of marker expression was similar in metastatic and primary non-small cell lung carcinoma. Other organs and their tumors were negative, with few exceptions. Non-small cell lung carcinomas positive for peripheral airway cell markers were associated with younger age and less-intense smoking, and surfactant-associated protein reactivity was more common in women than in men. Peripheral airway cell markers were independent prognostic factors for survival and delayed development of metastases in patients with less-advanced disease. It is concluded that surfactant-associated protein and 10-kD Clara cell protein are specific markers for non-small cell lung carcinoma and peripheral airway cell differentiation and provide useful tools to study the pathogenesis, biology, and prognosis of non-small cell lung carcinoma.