Microbial translocation augments the function of adoptively transferred self/tumor-specific CD8+ T cells via TLR4 signaling
Chrystal M. Paulos, … , Steven A. Rosenberg, Nicholas P. Restifo
Chrystal M. Paulos, … , Steven A. Rosenberg, Nicholas P. Restifo
Published August 1, 2007
Citation Information: J Clin Invest. 2007;117(8):2197-2204. https://doi.org/10.1172/JCI32205.
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Research Article Oncology

Microbial translocation augments the function of adoptively transferred self/tumor-specific CD8+ T cells via TLR4 signaling

Abstract

Lymphodepletion with total body irradiation (TBI) increases the efficacy of adoptively transferred tumor-specific CD8+ T cells by depleting inhibitory lymphocytes and increasing homeostatic cytokine levels. We found that TBI augmented the function of adoptively transferred CD8+ T cells in mice genetically deficient in all lymphocytes, indicating the existence of another TBI mechanism of action. Additional investigation revealed commensal gut microflora in the mesenteric lymph nodes and elevated LPS levels in the sera of irradiated mice. These findings correlated with increased dendritic cell activation and heightened levels of systemic inflammatory cytokines. Reduction of host microflora using antibiotics, neutralization of serum LPS using polymyxin B, or removal of LPS signaling components using mice genetically deficient in CD14 and TLR4 reduced the beneficial effects of TBI on tumor regression. Conversely, administration of microbial ligand–containing serum or ultrapure LPS from irradiated animals to nonirradiated antibody-lymphodepleted mice enhanced CD8+ T cell activation and improved tumor regression. Administration of ultrapure LPS to irradiated animals further enhanced the number and function of the adoptively transferred cells, leading to long-term cure of mice with large B16F10 tumors and enhanced autoimmune vitiligo. Thus, disruption of the homeostatic balance between the host and microbes can enhance cell-based tumor immunotherapy.

Authors

Chrystal M. Paulos, Claudia Wrzesinski, Andrew Kaiser,, Christian S. Hinrichs, Marcello Chieppa, Lydie Cassard, Douglas C. Palmer, Andrea Boni, Pawel Muranski, Zhiya Yu, Luca Gattinoni, Paul A. Antony, Steven A. Rosenberg, Nicholas P. Restifo

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Figure 5

Depletion of cytokine sinks, removal of Tregs, and activation of the innate immune system recapitulate the effectiveness of TBI.

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Depletion of cytokine sinks, removal of Tregs, and activation of the inn...
(A) Activation of the innate immune system with serum LPS, depletion of Tregs with anti-CD4 antibody, and removal of cytokine sinks with anti-NK antibody are required to improve the efficacy of adoptively transferred in nonirradiated mice. Tumor-bearing C57BL/6 mice received 5 Gy TBI or were left nonirradiated. Alternatively, mice were depleted of lymphocytes with CD4 and NK antibodies; 1 day later mice received 5 × 105 cultured pmel-1 T cells, rFPhgp100 vaccination, and IL-2. Serum for irradiated mice containing LPS was harvested and transferred into nonirradiated recipients. (B) Ultrapure LPS enhanced treatment in lymphodepleted nonirradiated mice. C57BL/6 mice were irradiated as a control. Mice received serum with translocated LPS or ultrapure LPS alone, CD4 alone, or NK-depleting antibody alone 1 day after ACT. Data (mean ± SEM; n = 4–5 per group) are representative of 2 independent experiments. (C) Ultrapure LPS recapitulated the effectiveness of TBI in Rag2–/–γc–/– mice genetically deficient in all lymphocytes. Data (mean ± SEM; n = 5 per group) are representative of 2 independent experiments. †P = 0.05 versus irradiated treated mice. The difference between the nonirradiated, treated, LPS-administered group and the irradiated treated group was not significant (P < 0.2).