Limits...
Tumor-derived microvesicles induce, expand and up-regulate biological activities of human regulatory T cells (Treg).

Szajnik M, Czystowska M, Szczepanski MJ, Mandapathil M, Whiteside TL - PLoS ONE (2010)

Bottom Line: Purified Treg were resistant to TMV-mediated apoptosis relative to other T cells.Neutralizing Abs specific for TGF-beta1 and/or IL-10 significantly inhibited TMV ability to expand Treg.They induce Treg, promote Treg expansion, up-regulate Treg suppressor function and enhance Treg resistance to apoptosis.

View Article: PubMed Central - PubMed

Affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America.

ABSTRACT

Background: Tumor-derived microvesicles (TMV) or exosomes are present in body fluids of patients with cancer and might be involved in tumor progression. The frequency and suppressor functions of peripheral blood CD4(+)CD25(high)FOXP3(+) Treg are higher in patients with cancer than normal controls. The hypothesis is tested that TMV contribute to induction/expansion/and activation of human Treg.

Methodology/principal findings: TMV isolated from supernatants of tumor cells but not normal cells induced the generation and enhanced expansion of human Treg. TMV also mediated conversion of CD4(+)CD25(neg) T cells into CD4(+)CD25(high)FOXP3(+) Treg. Upon co-incubation with TMV, Treg showed an increased FasL, IL-10, TGF-beta1, CTLA-4, granzyme B and perforin expression (p<0.05) and mediated stronger suppression of responder cell (RC) proliferation (p<0.01). Purified Treg were resistant to TMV-mediated apoptosis relative to other T cells. TMV also increased phospho-SMAD2/3 and phospho-STAT3 expression in Treg. Neutralizing Abs specific for TGF-beta1 and/or IL-10 significantly inhibited TMV ability to expand Treg.

Conclusions/significance: This study suggests that TMV have immunoregulatory properties. They induce Treg, promote Treg expansion, up-regulate Treg suppressor function and enhance Treg resistance to apoptosis. Interactions of TMV with Treg represent a newly-defined mechanism that might be involved in regulating peripheral tolerance by tumors and in supporting immune evasion of human cancers.

Show MeSH

Related in: MedlinePlus

TMV promote expansion of human Treg in culture.The fold expansion of fresh (left panel) or rapamycin-expanded (right panel) CD4+CD25high T cells to which TMV or DC-derived MV were added on day 0. Cells were stimulated with OKT3, anti-CD28 Abs and IL-2 (500 IU/mL) and cultured for 14–21 d. The data are means ± SD of six independent co-cultures. Asterisks indicate significant differences (p<0.05) between the cultures ± TMV.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2908536&req=5

pone-0011469-g003: TMV promote expansion of human Treg in culture.The fold expansion of fresh (left panel) or rapamycin-expanded (right panel) CD4+CD25high T cells to which TMV or DC-derived MV were added on day 0. Cells were stimulated with OKT3, anti-CD28 Abs and IL-2 (500 IU/mL) and cultured for 14–21 d. The data are means ± SD of six independent co-cultures. Asterisks indicate significant differences (p<0.05) between the cultures ± TMV.

Mentions: To determine whether TMV helped in sustaining Treg expansion in culture, freshly isolated or rapamycin-expanded CD4+CD25+ T cells stimulated with OKT3, anti-CD28 Ab and IL-2 (500 IU/mL) were cultured ± TMV (Figure 3). The fold expansion of Treg defined as CD4+CD25high T cells [30] was evaluated on days 7, 10, 14 and 21. In 2 week co-cultures of freshly isolated CD4+CD25+ T cells + TMV, Treg showed 12-fold mean expansion and only 3-fold mean expansion in the absence of TMV (Figure 3 left panel). As expected, rapamycin-expanded Treg proliferated better with the mean fold expansion of 34 on day 14 and of 40 on day 21 in TMV-containing cultures compared to 25-fold expansion at best for the cultures without TMV (Figure 3 right panel). The data are consistent with the conclusion that TMV promote expansion of Treg in culture.


Tumor-derived microvesicles induce, expand and up-regulate biological activities of human regulatory T cells (Treg).

Szajnik M, Czystowska M, Szczepanski MJ, Mandapathil M, Whiteside TL - PLoS ONE (2010)

TMV promote expansion of human Treg in culture.The fold expansion of fresh (left panel) or rapamycin-expanded (right panel) CD4+CD25high T cells to which TMV or DC-derived MV were added on day 0. Cells were stimulated with OKT3, anti-CD28 Abs and IL-2 (500 IU/mL) and cultured for 14–21 d. The data are means ± SD of six independent co-cultures. Asterisks indicate significant differences (p<0.05) between the cultures ± TMV.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2908536&req=5

pone-0011469-g003: TMV promote expansion of human Treg in culture.The fold expansion of fresh (left panel) or rapamycin-expanded (right panel) CD4+CD25high T cells to which TMV or DC-derived MV were added on day 0. Cells were stimulated with OKT3, anti-CD28 Abs and IL-2 (500 IU/mL) and cultured for 14–21 d. The data are means ± SD of six independent co-cultures. Asterisks indicate significant differences (p<0.05) between the cultures ± TMV.
Mentions: To determine whether TMV helped in sustaining Treg expansion in culture, freshly isolated or rapamycin-expanded CD4+CD25+ T cells stimulated with OKT3, anti-CD28 Ab and IL-2 (500 IU/mL) were cultured ± TMV (Figure 3). The fold expansion of Treg defined as CD4+CD25high T cells [30] was evaluated on days 7, 10, 14 and 21. In 2 week co-cultures of freshly isolated CD4+CD25+ T cells + TMV, Treg showed 12-fold mean expansion and only 3-fold mean expansion in the absence of TMV (Figure 3 left panel). As expected, rapamycin-expanded Treg proliferated better with the mean fold expansion of 34 on day 14 and of 40 on day 21 in TMV-containing cultures compared to 25-fold expansion at best for the cultures without TMV (Figure 3 right panel). The data are consistent with the conclusion that TMV promote expansion of Treg in culture.

Bottom Line: Purified Treg were resistant to TMV-mediated apoptosis relative to other T cells.Neutralizing Abs specific for TGF-beta1 and/or IL-10 significantly inhibited TMV ability to expand Treg.They induce Treg, promote Treg expansion, up-regulate Treg suppressor function and enhance Treg resistance to apoptosis.

View Article: PubMed Central - PubMed

Affiliation: University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America.

ABSTRACT

Background: Tumor-derived microvesicles (TMV) or exosomes are present in body fluids of patients with cancer and might be involved in tumor progression. The frequency and suppressor functions of peripheral blood CD4(+)CD25(high)FOXP3(+) Treg are higher in patients with cancer than normal controls. The hypothesis is tested that TMV contribute to induction/expansion/and activation of human Treg.

Methodology/principal findings: TMV isolated from supernatants of tumor cells but not normal cells induced the generation and enhanced expansion of human Treg. TMV also mediated conversion of CD4(+)CD25(neg) T cells into CD4(+)CD25(high)FOXP3(+) Treg. Upon co-incubation with TMV, Treg showed an increased FasL, IL-10, TGF-beta1, CTLA-4, granzyme B and perforin expression (p<0.05) and mediated stronger suppression of responder cell (RC) proliferation (p<0.01). Purified Treg were resistant to TMV-mediated apoptosis relative to other T cells. TMV also increased phospho-SMAD2/3 and phospho-STAT3 expression in Treg. Neutralizing Abs specific for TGF-beta1 and/or IL-10 significantly inhibited TMV ability to expand Treg.

Conclusions/significance: This study suggests that TMV have immunoregulatory properties. They induce Treg, promote Treg expansion, up-regulate Treg suppressor function and enhance Treg resistance to apoptosis. Interactions of TMV with Treg represent a newly-defined mechanism that might be involved in regulating peripheral tolerance by tumors and in supporting immune evasion of human cancers.

Show MeSH
Related in: MedlinePlus