Tumor-infiltrating lymphocytes: Streamlining a complex manufacturing process.

Adoptive cell therapy of tumor-infiltrating lymphocytes has shown promise for treatment of refractory melanoma and other solid malignancies; however, challenges to manufacturing have limited its widespread use. Traditional manufacturing efforts were lengthy, cumbersome and used open culture systems. We describe changes in testing and manufacturing that decreased the process cycle time, enhanced the robustness of critical quality attribute testing and facilitated a functionally closed system. These changes have enabled export of the manufacturing process to support multi-center clinical trials.

A phase I/randomized phase II study of GM.CD40L vaccine in combination with CCL21 in patients with advanced lung adenocarcinoma.

The GM.CD40L vaccine, which recruits and activates dendritic cells, migrates to lymph nodes, activating T cells and leading to systemic tumor cell killing. When combined with the CCL21 chemokine, which recruits T cells and enhances T-cell responses, additive effects have been demonstrated in non-small cell lung cancer mouse models. Here, we compared GM.CD40L versus GM.CD40L plus CCL21 (GM.CD40L.CCL21) in lung adenocarcinoma patients with ≥ 1 line of treatment. In this phase I/II randomized trial (NCT01433172), patients received intradermal vaccines every 14 days (3 doses) and then monthly (3 doses). A two-stage minimax design was used. During phase I, no dose-limiting toxicities were shown in three patients who received GM.CD40L.CCL21. During phase II, of evaluable patients, 5/33 patients (15.2%) randomized for GM.DCD40L (p = .023) and 3/32 patients (9.4%) randomized for GM.DCD40L.CCL21 (p = .20) showed 6-month progression-free survival. Median overall survival was 9.3 versus 9.5 months with GM.DCD40L versus GM.DCD40L.CCL21 (95% CI 0.70-2.25; p = .44). For GM.CD40L versus GM.CD40L.CCL21, the most common treatment-related adverse events (TRAEs) were grade 1/2 injection site reaction (51.4% versus 61.1%) and grade 1/2 fatigue (35.1% versus 47.2%). Grade 1 immune-mediated TRAEs were isolated to skin. No patients showed evidence of pseudo-progression or immune-related TRAEs of grade 1 or greater of pneumonitis, endocrinopathy, or colitis, and none discontinued treatment due to toxicity. Although we found no significant associations between vaccine immunogenicity and outcomes, in limited biopsies, one patient treated with GMCD40L.CCL21 displayed abundant tumor-infiltrating lymphocytes. This possible effectiveness warrants further investigation of GM.CD40L in combination approaches.

NF-κB is crucial in proximal T-cell signaling for calcium influx and NFAT activation.

In the accepted model of T-cell activation, parallel signal-transduction pathways activate the transcription factors NF-κB, NFAT, and AP-1 to drive clonal expansion of T cells in response to Ag. Genome-wide transcriptional profiling following Ag-induced CD8(+) T-cell activation in C57BL/6 mouse T cells revealed that genes regulated by NFAT were also reduced in the absence of NF-κB p50 and cRel subunits. Importantly, p50(-/-) cRel(-/-) CD8(+) T cells had significantly diminished NFAT and AP-1 activation compared with WT or PKCθ(-/-) CD8(+) T cells. Attenuated NFAT activation after TCR engagement was associated with reduced calcium influx, PLCγ and Zap70 activation. Interestingly, pharmacological bypass of PLCγ-regulated pathways largely rescued p50(-/-) cRel(-/-) T-cell proliferative defects. These results indicate a crucial and unexpected requirement for NF-κB p50 and cRel subunits in proximal TCR signaling and calcium responses. They further suggest that key defects in T cells in the absence of NF-κB pathway components may be due to impaired proximal T-cell signaling.

Lung tumor NF-κB signaling promotes T cell-mediated immune surveillance.

NF-κB is constitutively activated in many cancer types and is a potential key mediator of tumor-associated inflammation, tumor growth, and metastasis. We investigated the role of cancer cell NF-κB activity in T cell-mediated antitumor responses. In tumors rendered immunogenic by model antigen expression or following administration of antitumor vaccines, we found that high NF-κB activity leads to tumor rejection and/or growth suppression in mice. Using a global RNA expression microarray, we demonstrated that NF-κB enhanced expression of several T cell chemokines, including Ccl2, and decreased CCL2 expression was associated with enhanced tumor growth in a mouse lung cancer model. To investigate NF-κB function in human lung tumors, we identified a gene expression signature in human lung adenocarcinoma cell lines that was associated with NF-κB activity level. In patient tumor samples, overall lung tumor NF-κB activity was strongly associated with T cell infiltration but not with cancer cell proliferation. These results therefore indicate that NF-κB activity mediates immune surveillance and promotes antitumor T cell responses in both murine and human lung cancer.

IKKß-induced inflammation impacts the kinetics but not the magnitude of the immune response to a viral vector.

Microbial adjuvants in vaccines activate key transcription factors, including NF-κB and interferon response factors (IRFs). However, the individual role of these transcription factor pathways in promoting adaptive immunity by adjuvants is not clear. It is widely believed that induction of a strong inflammatory response potentiates an adaptive immune response. In this study, we sought to determine whether activation of the pro-inflammatory inhibitor of κB kinase ß (IKKß) canonical NF-κB pathway promoted vaccine-induced immune responses. An adenovirus expressing constitutively activated IKKß (AdIKK) induced robust DC maturation and high expression of key cytokines compared with a control virus. In vivo, AdIKK triggered rapid inflammation after pulmonary infection, increased leukocyte entry into draining LNs, and enhanced early antibody and T-cell responses. Notably, AdIKK did not influence the overall magnitude of the adaptive immune response. These results indicate that induction of inflammation by IKKß/NFκB in this setting impacts the kinetics but not the magnitude of adaptive immune responses. These findings therefore help define the individual role of a key pathway induced by vaccine adjuvants in promoting adaptive immunity.