Human rhinovirus (HRV) infections trigger exacerbations of asthma and chronic obstructive pulmonary disease (COPD) and are associated with lymphocytic infiltration of the airways. We demonstrate that infection of primary cultures of human airway epithelial cells, or of the BEAS-2B human bronchial epithelial cell line, with human rhinovirus type 16 (HRV-16) induces expression of CXCL10 [IFN-gamma-inducible protein 10 (IP-10)], a ligand for the CXCR3 receptor found on activated type 1 T lymphocytes and natural killer cells. IP-10 mRNA reached maximal levels 24 h after HRV-16 infection then declined, whereas protein levels peaked 48 h after infection with no subsequent new synthesis. Cytosolic levels of AU-rich factor 1, a protein associated with mRNA destabilization, increased beginning 24 h after HRV-16 infection. Generation of IP-10 required virus capable of replication but was not dependent on prior induction of type 1 interferons. Transfection of synthetic double-stranded RNA into epithelial cells induced robust production of IP-10, whereas transfection of single-stranded RNA had no effect. Induction of IP-10 gene expression by HRV-16 depended upon activation of NF-kappaB, as well as other transcription factor recognition sequences further upstream in the IP-10 promoter. In vivo infection of human volunteers with HRV-16 strikingly increased IP-10 protein in nasal lavages during symptomatic colds. Levels of IP-10 correlated with symptom severity, viral titer, and numbers of lymphocytes in airway secretions. Thus IP-10 may play a role in the pathogenesis of HRV-induced colds and in HRV-induced exacerbations of COPD and asthma.

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Granulysin is located in the acidic granules of cytotoxic T cells. Although the purified protein has antimicrobial activity against a broad spectrum of microbial pathogens, direct evidence for granulysin-mediated cytotoxicity has heretofore been lacking. Studies were performed to examine the regulation and activity of granulysin expressed by CD8 T cells using Cryptococcus neoformans, which is one of the most common opportunistic pathogens of AIDS patients. IL-15-activated CD8 T cells acquired anticryptococcal activity, which correlated with the up-regulation of granulysin. When granules containing granulysin were depleted using SrCl2, or when the gene was silenced using 21-nt small interfering RNA duplexes, the antifungal effect of CD8 T cells was abrogated. Concanamycin A and EGTA did not affect the antifungal effect, suggesting that the activity of granulysin was perforin independent. Following stimulation by the C. neoformans mitogen, CD8 T cells expressed granulysin and acquired antifungal activity. This activity required CD4 T cells and was dependent upon accessory cells. Furthermore, IL-15 was both necessary and sufficient for granulysin up-regulation in CD8 T cells. These observations are most consistent with a mechanism whereby C. neoformans mitogen is presented to CD4 T cells, which in turn activate accessory cells. The resultant IL-15 activates CD8 T cells to express granulysin, which is responsible for antifungal activity.

Different "professional" antigen-presenting cells (APC) have unique characteristics that favor or restrict presentation of microbial antigens to T cells, depending on the organism. Cryptococcus neoformans is a pathogenic yeast that presents unique challenges to APC, including its large size, its rigid cell wall, and its ability to stimulate T cells as a mitogen. T-cell proliferation in response to the C. neoformans mitogen (CnM) requires phagocytosis and processing of the organisms by accessory cells prior to presentation of CnM to T cells. Because of the requirement for uptake of the organism and more limited costimulatory requirements of mitogens, macrophages might be the most likely cellular source for the accessory cell. However, the present study demonstrates that a transiently adherent cell that was CD3 ؊ , CD14 ؊ , CD19 ؊ , CD56 ؊ , HLA-DR ؉ , and CD83؉ with a dendritic morphology, rather than monocyte-derived or tissue (alveolar) macrophages, was the most efficient APC for presentation of CnM. A large number of these cells bound and internalized the organism, and only a small number of dendritic cells were required for presentation of the mitogen to T cells. Further, the mannose receptor and Fc␥ receptor II were required for presentation of C. neoformans, as blocking either of these receptors abrogated both uptake of C. neoformans and lymphocyte proliferation in response to CnM. These studies demonstrate the surprising fact that dendritic cells are the most efficient accessory cells for CnM.

Reovirus is a nonattenuated double-stranded RNA virus that exploits aberrant signaling pathways allowing selective cytotoxicity against multiple cancer histologies. The use of reovirus as a potential treatment modality for prostate cancer has not previously been described, and in this study evidence of in vitro and in vivo activity against prostate cancer was seen both in preclinical models and in six patients. The human prostate carcinoma cell lines PC-3, LN-CaP, and DU-145 exposed to replication-competent reovirus showed evidence of infection as illustrated by viral protein synthesis, cytopathic effect, and release of viral progeny. This oncolytic effect was found to be manifested through apoptosis, as DNA fragmentation, Apo 2.7 expression, Annexin V binding, and poly(ADP-ribose) polymerase cleavage were observed in live reovirus-infected cells, but not in uninfected or dead virus-treated cells. In vivo, hind flank severe combined immunodeficient/nonobese diabetic murine xenograft showed reduction in tumor size when treated with even a single intratumoral injection of reovirus. Finally, intralesional reovirus injections into a cohort of six patients with clinically organ-confined prostate cancer resulted in minimal side effects and evidence of antitumor activity. Histologic analysis after prostatectomy found a significant CD8 T-cell infiltration within the reovirus-injected areas as well as evidence of increased caspase-3 activity. These findings suggest that reovirus therapy may provide a promising novel treatment for prostate cancer and also imply a possible role for viral immune targeting of tumor. Cancer Res; 70(6); 2435-44. ©2010 AACR.