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Endogenous tumor-reactive CD8(+) T cells are differentiated effector cells expressing high levels of CD11a and PD-1 but are unable to control tumor growth.

Liu X, Gibbons RM, Harrington SM, Krco CJ, Markovic SN, Kwon ED, Dong H - Oncoimmunology (2013)

Bottom Line: In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, reliable biomarkers are needed.In the peripheral blood of melanoma patients, tumor antigen-specific CD8(+) T cells were associated with a population of CD11a(high) CD8(+) T cells that co-expressed high levels of PD-1.Increased CD11a(high)CD8(+) T cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector functions of CD8(+) T cells is compromised by an elevated expression of PD-1.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology; College of Medicine; Mayo Clinic; Rochester, MN USA.

ABSTRACT
Immunotherapies aimed at enhancing natural or endogenous antitumor T-cell immunity in patients affected by advanced malignancies are currently being implemented in the clinic with promising results. In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, reliable biomarkers are needed. We used CD11a, an integrin that is upregulated on the surface of effector and memory CD8(+) T cells, and PD-1, an immunoregulatory receptor expressed by activated T cells, as biomarkers to identify, quantify and monitor endogenous tumor-reactive cytotoxic T lymphocytes (CTLs) in two mouse tumor models and in the peripheral blood of 12 patients affected by Stage IV melanoma. High expression levels of CD11a and PD-1 were detected among CD8(+) T cells residing within primary and metastatic murine tumor sites, as well as in spontaneous murine breast cancer tissues. In the peripheral blood of melanoma patients, tumor antigen-specific CD8(+) T cells were associated with a population of CD11a(high) CD8(+) T cells that co-expressed high levels of PD-1. Healthy donors exhibited a comparatively much lower frequency of such PD-1(+)CD11a(high)CD8(+) T cells. Phenotypic analyses demonstrated that CD11a(high)CD8(+) T cells are proliferating (Ki67(+)) and activated (CD62L(-)CD69(+)). Increased CD11a(high)CD8(+) T cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector functions of CD8(+) T cells is compromised by an elevated expression of PD-1. The CD11a(high)CD8(+) T-cell population expresses high levels of PD-1 and presumably constitutes the cellular target of PD-1 blockade therapy. The expression level of CD11a and PD-1 by CD8(+) T cells may therefore represent a novel biomarker to identify and monitor endogenous tumor-reactive CTLs. This may not only provide an immunological readout for evaluating the efficacy of immunotherapy but also contribute to the selection of cancer patients who are likely to benefit from anti-PD-1 therapy.

No MeSH data available.


Related in: MedlinePlus

Figure 1. Endogenous tumor-specific CD8+ T cells in neoplastic lesions. (A–D) B16-OVA tumor cells were subcutaneously injected into naïve C57BL/6 mice. (A) On day 14 after tumor-cell injection, lymphocytes were isolated from neoplastic lesions and spleens and were stained with antibodies specific for CD3, CD8, CD11a, CD69 as well as with a KbOVA tetramer (KbOVA-tet). The frequency of CD11ahigh cells among CD8+ T cells in the tumor tissue and spleens of tumor-bearing or naïve mice is reported (n = 10). (B) Antigen specificity of CD11ahigh and CD11alowCD8+ T cells. (C) Cytotoxic T lymphocyte (CTL) activity of CD11ahigh and CD11alowCD8+ T cells following re-stimulation with OVA or control peptide for 5 h ex vivo. One of three independent experiments is shown. (D) Kinetics and distribution of functional CD11ahighCD8+ T cells in tumor tissues, draining lymph nodes (DLNs), non-draining lymph nodes (NDLNs) and spleen. The average percentage ± SD of CD107a+IFNγ+ cells among CD11ahigh CD8+ T cells is shown (n = 3).
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Figure 1: Figure 1. Endogenous tumor-specific CD8+ T cells in neoplastic lesions. (A–D) B16-OVA tumor cells were subcutaneously injected into naïve C57BL/6 mice. (A) On day 14 after tumor-cell injection, lymphocytes were isolated from neoplastic lesions and spleens and were stained with antibodies specific for CD3, CD8, CD11a, CD69 as well as with a KbOVA tetramer (KbOVA-tet). The frequency of CD11ahigh cells among CD8+ T cells in the tumor tissue and spleens of tumor-bearing or naïve mice is reported (n = 10). (B) Antigen specificity of CD11ahigh and CD11alowCD8+ T cells. (C) Cytotoxic T lymphocyte (CTL) activity of CD11ahigh and CD11alowCD8+ T cells following re-stimulation with OVA or control peptide for 5 h ex vivo. One of three independent experiments is shown. (D) Kinetics and distribution of functional CD11ahighCD8+ T cells in tumor tissues, draining lymph nodes (DLNs), non-draining lymph nodes (NDLNs) and spleen. The average percentage ± SD of CD107a+IFNγ+ cells among CD11ahigh CD8+ T cells is shown (n = 3).

Mentions: We monitored the presence of CD11ahighCD8+ T cells in mice harboring a subcutaneous tumor and analyzed TAA-specific CTL effector functions. B16-OVA tumor cells (engineered to express ovalbumin as a surrogate TAA) were injected subcutaneously into naïve C57BL/6 (B6) mice. Fourteen days after tumor-cell injection, lymphocytes were isolated from the spleen, tumor, tumor-draining lymph nodes (DLNs) and non-draining lymph nodes (NDLNs). CD11ahighCD8+ T cells were primarily detected within tumor lesions (66.7 ± 4.1% of CD8+ T cells) rather than in the spleen of tumor-bearing mice (13.4 ± 1.1% of CD8+ T cells, Fig. 1A), suggesting a tumor-associated accumulation of CD11ahighCD8+ T cells. The spleens of naïve mice contained fewer CD11ahighCD8+ T cells than those of tumor-bearing mice (3.9 ± 0.4% of CD8+ T cells, Fig. 1A). As shown in Figure S1, the subset of CD11ahighCD8+ T cells in both the spleen and tumor lesions also expressed high levels of CD18. In this setting, CD11ahighCD8+ T cells did not express higher levels of CD11b and expressed slightly increased levels of CD11c than their CD11alow counterparts (Fig. S1). These results suggest that CD11ahighCD8+ T cells are a subset of CD8+ T cells exhibiting a selective increase in the expression of LFA-1 (CD11a/CD18) rather than other β2 integrins including macrophage 1 antigen (Mac1, CD11b/CD18) or p150/95 (CD11c/CD18). We investigated the expression levels of ICAM-1 (CD54), the LFA-1 ligand, in B16-OVA tumor cells and endothelial cells within neoplastic lesions. B16-OVA cells expressed modest levels of ICAM-1 before inoculation into mice, which did not change in vivo. Conversely, endothelial cells within the tumor lesions, identified by CD31 expression, expressed high ICAM-1 levels (Fig. S2).


Endogenous tumor-reactive CD8(+) T cells are differentiated effector cells expressing high levels of CD11a and PD-1 but are unable to control tumor growth.

Liu X, Gibbons RM, Harrington SM, Krco CJ, Markovic SN, Kwon ED, Dong H - Oncoimmunology (2013)

Figure 1. Endogenous tumor-specific CD8+ T cells in neoplastic lesions. (A–D) B16-OVA tumor cells were subcutaneously injected into naïve C57BL/6 mice. (A) On day 14 after tumor-cell injection, lymphocytes were isolated from neoplastic lesions and spleens and were stained with antibodies specific for CD3, CD8, CD11a, CD69 as well as with a KbOVA tetramer (KbOVA-tet). The frequency of CD11ahigh cells among CD8+ T cells in the tumor tissue and spleens of tumor-bearing or naïve mice is reported (n = 10). (B) Antigen specificity of CD11ahigh and CD11alowCD8+ T cells. (C) Cytotoxic T lymphocyte (CTL) activity of CD11ahigh and CD11alowCD8+ T cells following re-stimulation with OVA or control peptide for 5 h ex vivo. One of three independent experiments is shown. (D) Kinetics and distribution of functional CD11ahighCD8+ T cells in tumor tissues, draining lymph nodes (DLNs), non-draining lymph nodes (NDLNs) and spleen. The average percentage ± SD of CD107a+IFNγ+ cells among CD11ahigh CD8+ T cells is shown (n = 3).
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Related In: Results  -  Collection

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Figure 1: Figure 1. Endogenous tumor-specific CD8+ T cells in neoplastic lesions. (A–D) B16-OVA tumor cells were subcutaneously injected into naïve C57BL/6 mice. (A) On day 14 after tumor-cell injection, lymphocytes were isolated from neoplastic lesions and spleens and were stained with antibodies specific for CD3, CD8, CD11a, CD69 as well as with a KbOVA tetramer (KbOVA-tet). The frequency of CD11ahigh cells among CD8+ T cells in the tumor tissue and spleens of tumor-bearing or naïve mice is reported (n = 10). (B) Antigen specificity of CD11ahigh and CD11alowCD8+ T cells. (C) Cytotoxic T lymphocyte (CTL) activity of CD11ahigh and CD11alowCD8+ T cells following re-stimulation with OVA or control peptide for 5 h ex vivo. One of three independent experiments is shown. (D) Kinetics and distribution of functional CD11ahighCD8+ T cells in tumor tissues, draining lymph nodes (DLNs), non-draining lymph nodes (NDLNs) and spleen. The average percentage ± SD of CD107a+IFNγ+ cells among CD11ahigh CD8+ T cells is shown (n = 3).
Mentions: We monitored the presence of CD11ahighCD8+ T cells in mice harboring a subcutaneous tumor and analyzed TAA-specific CTL effector functions. B16-OVA tumor cells (engineered to express ovalbumin as a surrogate TAA) were injected subcutaneously into naïve C57BL/6 (B6) mice. Fourteen days after tumor-cell injection, lymphocytes were isolated from the spleen, tumor, tumor-draining lymph nodes (DLNs) and non-draining lymph nodes (NDLNs). CD11ahighCD8+ T cells were primarily detected within tumor lesions (66.7 ± 4.1% of CD8+ T cells) rather than in the spleen of tumor-bearing mice (13.4 ± 1.1% of CD8+ T cells, Fig. 1A), suggesting a tumor-associated accumulation of CD11ahighCD8+ T cells. The spleens of naïve mice contained fewer CD11ahighCD8+ T cells than those of tumor-bearing mice (3.9 ± 0.4% of CD8+ T cells, Fig. 1A). As shown in Figure S1, the subset of CD11ahighCD8+ T cells in both the spleen and tumor lesions also expressed high levels of CD18. In this setting, CD11ahighCD8+ T cells did not express higher levels of CD11b and expressed slightly increased levels of CD11c than their CD11alow counterparts (Fig. S1). These results suggest that CD11ahighCD8+ T cells are a subset of CD8+ T cells exhibiting a selective increase in the expression of LFA-1 (CD11a/CD18) rather than other β2 integrins including macrophage 1 antigen (Mac1, CD11b/CD18) or p150/95 (CD11c/CD18). We investigated the expression levels of ICAM-1 (CD54), the LFA-1 ligand, in B16-OVA tumor cells and endothelial cells within neoplastic lesions. B16-OVA cells expressed modest levels of ICAM-1 before inoculation into mice, which did not change in vivo. Conversely, endothelial cells within the tumor lesions, identified by CD31 expression, expressed high ICAM-1 levels (Fig. S2).

Bottom Line: In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, reliable biomarkers are needed.In the peripheral blood of melanoma patients, tumor antigen-specific CD8(+) T cells were associated with a population of CD11a(high) CD8(+) T cells that co-expressed high levels of PD-1.Increased CD11a(high)CD8(+) T cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector functions of CD8(+) T cells is compromised by an elevated expression of PD-1.

View Article: PubMed Central - PubMed

Affiliation: Department of Urology; College of Medicine; Mayo Clinic; Rochester, MN USA.

ABSTRACT
Immunotherapies aimed at enhancing natural or endogenous antitumor T-cell immunity in patients affected by advanced malignancies are currently being implemented in the clinic with promising results. In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, reliable biomarkers are needed. We used CD11a, an integrin that is upregulated on the surface of effector and memory CD8(+) T cells, and PD-1, an immunoregulatory receptor expressed by activated T cells, as biomarkers to identify, quantify and monitor endogenous tumor-reactive cytotoxic T lymphocytes (CTLs) in two mouse tumor models and in the peripheral blood of 12 patients affected by Stage IV melanoma. High expression levels of CD11a and PD-1 were detected among CD8(+) T cells residing within primary and metastatic murine tumor sites, as well as in spontaneous murine breast cancer tissues. In the peripheral blood of melanoma patients, tumor antigen-specific CD8(+) T cells were associated with a population of CD11a(high) CD8(+) T cells that co-expressed high levels of PD-1. Healthy donors exhibited a comparatively much lower frequency of such PD-1(+)CD11a(high)CD8(+) T cells. Phenotypic analyses demonstrated that CD11a(high)CD8(+) T cells are proliferating (Ki67(+)) and activated (CD62L(-)CD69(+)). Increased CD11a(high)CD8(+) T cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector functions of CD8(+) T cells is compromised by an elevated expression of PD-1. The CD11a(high)CD8(+) T-cell population expresses high levels of PD-1 and presumably constitutes the cellular target of PD-1 blockade therapy. The expression level of CD11a and PD-1 by CD8(+) T cells may therefore represent a novel biomarker to identify and monitor endogenous tumor-reactive CTLs. This may not only provide an immunological readout for evaluating the efficacy of immunotherapy but also contribute to the selection of cancer patients who are likely to benefit from anti-PD-1 therapy.

No MeSH data available.


Related in: MedlinePlus