Cyclooxygenase-2 (COX-2), the enzyme at the rate-limiting step of prostanoid production, has been found to be overexpressed in human lung cancer. To evaluate lung tumor COX-2 modulation of antitumor immunity, we studied the antitumor effect of specific genetic or pharmacological inhibition of COX-2 in a murine Lewis lung carcinoma (3LL) model. Inhibition of COX-2 led to marked lymphocytic infiltration of the tumor and reduced tumor growth. Treatment of mice with anti-PGE2 mAb replicated the growth reduction seen in tumor-bearing mice treated with COX-2 inhibitors. COX-2 inhibition was accompanied by a significant decrement in IL-10 and a concomitant restoration of IL-12 production by APCs. Because the COX-2 metabolite PGE2 is a potent inducer of IL-10, it was hypothesized that COX-2 inhibition led to antitumor responses by down-regulating production of this potent immunosuppressive cytokine. In support of this concept, transfer of IL-10 transgenic T lymphocytes that overexpress IL-10 under control of the IL-2 promoter reversed the COX-2 inhibitor-induced antitumor response. We conclude that abrogation of COX-2 expression promotes antitumor reactivity by restoring the balance of IL-10 and IL-12 in vivo.

In two murine lung cancer models adenoviral interleukin 7-transduced dendritic cells (DC-AdIL-7) were administered intratumorally, resulting in complete tumor regression. Intratumoral DC-AdIL-7 therapy was as effective as DCs pulsed with specific tumor peptide antigens. Comparison with other intratumoral therapies including recombinant IL-7, AdIL-7 vector alone, unmodified DCs, IL-7-transduced fibroblasts, or DCs pulsed with tumor lysates revealed DC-AdIL-7 therapy to be superior in achieving antitumor responses and augmenting immunogenicity. Mice with complete tumor eradication as a result of either DC-AdIL-7 or AdIL-7 therapy were rechallenged with parental tumor cells 30 days or more after complete tumor eradication. All the DC-AdIL-7-treated mice completely rejected a secondary rechallenge, whereas the AdIL-7-treated mice had sustained antitumor effects in only 20-25% of the mice. DC-AdIL-7 therapy was more effective than AdIL-7 in achieving systemic antitumor responses and enhancing immunogenicity. After complete tumor eradication, those mice treated with DC-AdIL-7 evidenced significantly greater release of splenocyte GM-CSF and IFN-gamma than did controls or AdIL-7-treated mice. After intratumoral injection, gene-modified DCs trafficked from the tumor to lymph node sites and spleen. DCs were detected in nodal tissues for up to 7 days after intratumoral injection. We report that intratumoral DC-AdIL-7 leads to significant systemic immune responses and potent antitumor effects in murine lung cancer models.

More than 500 mutations have been identified in the CFTR gene, making it an excellent system for testing mutation scanning techniques. To assess the sensitivity of denaturing gradient gel electrophoresis (DGGE), we collected a representative group of 202 CFTR mutations. All mutations analyzed were detected by scanning methods other than the DGGE approach evaluated in this study. DGGE analysis was performed on 24 of the 27 exons and their flanking splice site sequences. After optimization, 201 of the 202 control samples produced an altered migration pattern in the region in which an alteration occurred. The remaining sample was sequenced and found not to have the reported mutation. The ability of DGGE to identify novel mutations was evaluated in three Asian CF patients with four unknown CF alleles. Three novel Asian mutations were detected-K166E, L568X, and 3121-2 A-->G (in homozygosity)-accounting for all CF alleles. These results indicate that an optimized DGGE scanning strategy is highly sensitive and specific and can detect 100% of mutations.

These results lend further support to a possible link between CF mutations and ABPA.