The exceptional immunostimulatory capacity of DCs makes them potential targets for investigation of cancer immunotherapeutics. We show here in mice that TNF-α–stimulated DC maturation was accompanied by increased expression of OX40 ligand (OX40L), the lack of which resulted in an inability of mature DCs to generate cellular antitumor immunity. Furthermore, intratumoral administration of DCs modified to express OX40L suppressed tumor growth through the generation of tumor-specific cytolytic T cell responses, which were mediated by CD4⁺ T cells and NKT cells. In the tumors treated with OX40L-expressing DCs, the NKT cell population significantly increased and exhibited a substantial level of IFN-γ production essential for antitumor immunity. Additional studies evaluating NKT cell activation status, in terms of IFN-γ production and CD69 expression, indicated that NKT cell activation by DCs presenting α-galactosylceramide in the context of CD1d was potentiated by OX40 expression on NKT cells. These results show a critical role for OX40L on DCs, via binding to OX40 on NKT cells and CD4⁺ T cells, in the induction of antitumor immunity in tumor-bearing mice.

Chronic pulmonary aspergillosis (CPA) is a common sequela of pulmonary tuberculosis (TB). The diagnosis of CPA is difficult and often misdiagnosed as smear-negative TB in endemic settings. Aspergillus IgG detection is the cornerstone of CPA diagnosis. There are a lack of studies on the prevalence of CPA in GeneXpert/smear-negative TB patients in Indonesia, despite a high number of TB cases. This study aims to determine the CPA rate in HIV-negative, GeneXpert-negative patients presenting with symptoms following completion of TB therapy and to evaluate the performance of LDBio Aspergillus immunochromatographic technology (ICT) lateral flow assay in the diagnosis of CPA. CPA was diagnosed on the basis of symptoms for ≥3 months, characteristic chest imaging and positive Aspergillus culture. Twenty (22%) out of 90 patients met the criteria for CPA. The LDBio test was positive in 16 (80%) CPA patients and in 21 (30%) non-CPA patients (p < 0.001) with 80% sensitivity and 70% specificity. Logistic regression revealed a positive LDBio Aspergillus ICT result, smoking history and diabetes to be important predictors of CPA diagnosis. Although CPA is an unrecognised disease in Indonesia, this study suggests that more than one in five GeneXpert negative patients with persistent symptoms following completion of TB therapy may have CPA.

Fractalkine (CX3CL1) is a unique membrane‐bound CX3C chemokine that serves as a potent chemoattractant for lymphocytes. The hypothesis of this study is that dendritic cells (DC) genetically modifiedex vivoto overexpress fractalkine would enhance the T cell‐mediated cellular immune response with a consequent induction of anti‐tumor immunity to suppress tumor growth. To prove this hypothesis, established tumors of different mouse cancer cells (B16‐F10 melanoma, H‐2^b, and Colon‐26 colon adenocarcinoma, H‐2^d) were treated with intratumoral injection of bone marrow‐derived DC that had been modifiedin vitrowith an RGD fiber‐mutant adenovirus vector expressing mouse fractalkine (Ad‐FKN). In both tumor models tested, treatment of tumor‐bearing mice with Ad‐FKN‐transduced DC gave rise to a significant suppression of tumor growth along with survival advantages in the treated mice. Immunohistochemical analysis of tumors treated with direct injection of Ad‐FKN‐transduced DC demonstrated that the treatment prompted CD8⁺T cells and CD4⁺T cells to accumulate in the tumor milieu, leading to activation of immune‐relevant processes. Consistent with the finding, the intratumoral administration of Ad‐FKN‐transduced DC evoked tumor‐specific cytotoxic T lymphocytes, which ensued fromin vivopriming of Th1 immune responses in the treated host. In addition, the anti‐tumor effect provided by intratumoral injection of Ad‐FKN‐transduced DC was completely abrogated in CD4⁺T cell‐deficient mice as well as in CD8⁺T cell‐deficient mice. These results support the concept that genetic modification of DC with a recombinant fractalkine adenovirus vector may be a useful strategy for cancer immunotherapy protocols.

Rationale: OX40–OX40 ligand (OX40L) interactions have been proposed to support induction of allergic airway inflammation, which may be attributable to OX40 signaling in CD4⁺ helper T cells for adaptive immune responses. However, a possible involvement of natural killer T (NKT) cells in the pathogenesis suggests that the underlying mechanisms are not yet fully elucidated. Objectives: We aimed to characterize the OX40-modulated cellular contribution to allergic airway inflammation in a mouse model of house dust mite (HDM) allergen exposure. Methods: Mice were sensitized to HDM and, 3 weeks later, challenged with HDM on three consecutive days through the airways. Two days after the last exposure, bronchoalveolar lavage fluids and blood samples and lung tissues were evaluated for the airway inflammation. Measurements and Main Results: The development of HDM-induced eosinophilic airway inflammation was dependent on OX40 of both CD4⁺ T cells and NKT cells; OX40 engagement on CD4⁺ T cells in the sensitization led to pulmonary OX40L augmentation after the allergen challenge, which stimulated pulmonary NKT cells through OX40 to provide the pathogenic cytokine milieu. This was ablated by OX40L blockade by inhalation of the neutralizing antibody during the challenge, suggesting the therapeutic potential of targeting pulmonary OX40–OX40L interactions. Moreover, OX40 expression in CD4⁺ T cells, but not in NKT cells, was reciprocally regulated by the helper T cell type 1–skewing transcription factor Runx3. Conclusions: OX40 on not only CD4⁺ T cells but also NKT cells is involved in allergic airway inflammation. Notably, pulmonary blockade of OX40 ligation on NKT cells has therapeutic implications.

The detection of Aspergillus antibody has a key role in the diagnosis of chronic pulmonary aspergillosis. Western blot (WB) and immunochromatography (ICT) lateral flow detection of Aspergillus antibody can be used as confirmatory and screening assays but their comparative performance in TB patients is not known. This study investigated the performance of these assays among 88 post-tuberculosis patients with suspected CPA. Sensitivity, specificity, receiver operating curve (ROC), area under-curve (AUC) and the agreement between two assays were evaluated. Both WB and ICT showed good sensitivity (80% and 85%, respectively) for detection of Aspergillus antibodies. Substantial agreement (0.716) between these assays was also obtained. The highest AUC result (0.804) was achieved with the combination of WB and ICT. The global intensity of WB correlated with the severity of symptoms in CPA group (p = 0.001). The combination of WB and ICT may increase specificity in CPA diagnosis.