Messenger RNA encoding constitutively active Toll-like receptor 4 enhances effector functions of human T cells.

Adoptive T cell therapy of cancer employs a large number of ex-vivo-propagated T cells which recognize their targets either by virtue of their endogenous T cell receptor (TCR) or via genetic reprogramming. However, both cell-extrinsic and intrinsic mechanisms often diminish the in-vivo potency of these therapeutic T cells, limiting their clinical efficacy and broader use. Direct activation of human T cells by Toll-like receptor (TLR) ligands induces T cell survival and proliferation, boosts the production of proinflammatory cytokines and augments resistance to regulatory T cell (Treg) suppression. Removal of the TLR ligand-binding region results in constitutive signalling triggered by the remaining cytosolic Toll/interleukin-1 receptor (TIR) domain. The use of such TIR domains therefore offers an ideal means for equipping anti-tumour T cells with the arsenal of functional attributes required for improving current clinical protocols. Here we show that constitutively active (ca)TLR-4 can be expressed efficiently in human T cells using mRNA electroporation. The mere expression of caTLR-4 mRNA in polyclonal CD8 and CD4 T cells induced the production of interferon (IFN)-γ, triggered the surface expression of CD25, CD69 and 4-1BB and up-regulated a panel of cytokines and chemokines. In tumour-infiltrating lymphocytes prepared from melanoma patients, caTLR-4 induced robust IFN-γ secretion in all samples tested. Furthermore, caTLR-4 enhanced the anti-melanoma cytolytic activity of tumour-infiltrating lymphocytes and augmented the secretion of IFN-γ, tumour necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (GM-CSF) for at least 4 days post-transfection. Our results demonstrate that caTLR-4 is capable of exerting multiple T cell-enhancing effects and can potentially be used as a genetic adjuvant in adoptive cell therapy.

Informal caregiving to older cancer patients: preliminary research outcomes and implications.

BACKGROUND: The population of the Western world is aging while cancer survival rates are rising. Older patients with cancer will increasingly be taken care of by informal family caregivers. The current study describes levels of psychological distress, social support and coping abilities reported by partners who are caregivers to older patients with cancer (60+ years), comparing them to a control group of spouses of similarly aged people not suffering from life-threatening illness. PATIENTS AND METHODS: Two hundred sixteen partners who are primary caregivers of cancer patients aged 60+ were compared with 76 partners of healthy people aged 60+ and never diagnosed with any terminal illness. Participants completed self-reporting measures on psychological distress, coping ability and social support. RESULTS: Caregivers to cancer patients reported high levels of distress, low levels of social support and low levels of coping abilities which are negatively correlated to distress. Increased patient age was found to accentuate these processes. CONCLUSION: Age and the progression of cancer as a chronic illness present the physician with the reality that focus of care should be on the dyad (patient and caregiver), with high priority given to partners who are informal caregivers.

HLA-B35 correlates with a favorable outcome following adjuvant administration of an HLA-matched allogeneic melanoma vaccine.

This work presents survival data of 42 melanoma patients at high risk for disease recurrence who received an allogeneic melanoma vaccine composed of three cell lines, each matching at least one allele of the recipient's human leukocyte antigen (HLA)-A and -B loci. The 5-year overall survival (OS) rate and disease-free survival (DFS) compared favorably with the standard interferon-α regimen. Interestingly, patients bearing HLA-B35 had significantly better OS and DFS (OS of 100% and DFS of 90% for HLA-B35 vs 56% and 23%, for the non-B35 patients). In contrast, patients expressing HLA-B07 did not fare well with the vaccine. Although the data include a relatively small cohort of patients, it strongly hints toward a correlation between HLA types and potential benefit from anticancer immunotherapy.

Anti-leukemia effect of ex vivo expanded DNT cells from AML patients: a potential novel autologous T-cell adoptive immunotherapy.

CD3(+)CD56(-), CD4 and CD8 double negative T (DNT) cells comprise 1-3% of peripheral blood (PB) mononuclear cells. Their role in tumor immunity remains largely unknown due to their limited numbers and lack of effective methods to expand them. Here we developed a novel protocol by which DNT cells can be expanded ex vivo to therapeutic levels in 2 weeks from 13 of 16 acute myeloid leukemia (AML) patients during chemotherapy-induced complete remission. The expanded DNT cells expressed similar or higher levels of interferon-γ and tumor necrosis factor-α and Granzyme B as that seen in bulk activated CD8T cells from the same patient but significantly higher levels of perforin. The expanded DNT cells could effectively kill both allogeneic and autologous primary CD34(+) leukemic blasts isolated from PB of AML patients in a perforin-dependant manner. These results demonstrate, for the first time, that DNT cells from AML patients can be expanded ex vivo even after intensive chemotherapy, and are effective at killing both allogeneic and autologous primary leukemic blasts. These findings warrant studies further exploring the potential of DNT cells as a novel adjuvant immunotherapy to decrease the risk of relapse in patients with AML and, perhaps, other cancers.

Interleukin-2 improves tumour response to DNP-modified autologous vaccine for the treatment of metastatic malignant melanoma.

This paper is a report of response rate (RR) and survival of 34 metastatic melanoma patients who received a dinitrophenyl (DNP)-modified autologous melanoma cell vaccine. In all, 27 patients started the vaccine as a primary treatment for metastatic melanoma and seven started it as an adjuvant, with no evidence of disease at the time, but had developed new metastases. Interleukin-2 (IL-2) was administered in 24 out of the 34 patients: 19 who progressed on vaccine alone and five who had the combination from start. Interleukin-2 was administered in the intravenous, bolus high-dose regimen (seven patients) or as subcutaneous (s.c.) low-dose treatment (17). Overall response for the entire group was 35% (12 patients out of 34), 12% having a complete response (CR) and 23% a partial response (PR). However, only two patients had tumour responses while on the vaccine alone, whereas the other 10 demonstrated objective tumour regression following the combination with IL-2 (two CR, eight PR), lasting for a median duration of 6 months (range 3-50 months). Of the 12 responding patients, 11 attained strong skin reactivity to the s.c. injection of irradiated, unmodified autologous melanoma cells. None of the patients with a negative reactivity experienced any tumour response. Patients with positive skin reactions survived longer (median survival - 54 months). The results suggest enhanced RRs to the combination of IL-2 and autologous melanoma vaccine. Skin reactivity to unmodified autologous melanoma cells may be a predictor of response and improved survival, and therefore a criterion for further pursuing of immunotherapeutic strategies.