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Immune responses to RHAMM in patients with acute myeloid leukemia after chemotherapy and allogeneic stem cell transplantation.

Casalegno-Garduño R, Meier C, Schmitt A, Spitschak A, Hilgendorf I, Rohde S, Hirt C, Freund M, Pützer BM, Schmitt M - Clin. Dev. Immunol. (2012)

Bottom Line: Leukemic blasts overexpress immunogenic antigens, so-called leukemia-associated antigens like the receptor for hyaluronan acid-mediated motility (RHAMM).Results were correlated with the clinical outcome of patients.Immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the outcome of AML/MDS patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine III, University of Rostock, 18057 Rostock, Germany.

ABSTRACT
Leukemic blasts overexpress immunogenic antigens, so-called leukemia-associated antigens like the receptor for hyaluronan acid-mediated motility (RHAMM). Persistent RHAMM expression and decreasing CD8+ T-cell responses to RHAMM in the framework of allogeneic stem cell transplantation or chemotherapy alone might indicate the immune escape of leukemia cells. In the present study, we analyzed the expression of RHAMM in 48 patients suffering from acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Furthermore, we correlated transcripts with the clinical course of the disease before and after treatment. Real-time quantitative reverse transcriptase polymerase chain reaction was performed from RNA of peripheral blood mononuclear cells. T cell responses against RHAMM were assessed by tetramer staining (flow cytometry) and enzyme-linked immunospot (ELISPOT) assays. Results were correlated with the clinical outcome of patients. The results of the present study showed that almost 60% of the patients were RHAMM positive; specific T-cells recognizing RHAMM could be detected, but they were nonfunctional in terms of interferon gamma or granzyme B release as demonstrated by ELISPOT assays. Immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the outcome of AML/MDS patients.

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Related in: MedlinePlus

RHAMM-specific CTLs are present, but not functional. PBMCs were obtained from an AML patient who received chemotherapy. (a), (b). RHAMM-specific CTLs detected by flow cytometry at the stage of smoldering leukemia (c)–(f) and at the stage of progressive disease (g)–(j) did not release neither IFN-γ (a), nor granzyme B (b) at a level higher than background (no peptide control) as assessed by ELISPOT assays. (c)–(j) Reported frequencies correspond to all cells in the CD3+CD8+ T-cell gate (upper numbers), and to all cells in the lymphocyte gate (lower numbers). (c), (g) Isotype negative control, (d), (h) Non-peptide negative control, stained with an irrelevant tetramer, (e), (i) Non-peptide negative control, stained with RHAMM tetramer, (f), (j) CD8+ T cells were stimulated with RHAMM peptide and stained with RHAMM tetramer.
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fig4: RHAMM-specific CTLs are present, but not functional. PBMCs were obtained from an AML patient who received chemotherapy. (a), (b). RHAMM-specific CTLs detected by flow cytometry at the stage of smoldering leukemia (c)–(f) and at the stage of progressive disease (g)–(j) did not release neither IFN-γ (a), nor granzyme B (b) at a level higher than background (no peptide control) as assessed by ELISPOT assays. (c)–(j) Reported frequencies correspond to all cells in the CD3+CD8+ T-cell gate (upper numbers), and to all cells in the lymphocyte gate (lower numbers). (c), (g) Isotype negative control, (d), (h) Non-peptide negative control, stained with an irrelevant tetramer, (e), (i) Non-peptide negative control, stained with RHAMM tetramer, (f), (j) CD8+ T cells were stimulated with RHAMM peptide and stained with RHAMM tetramer.

Mentions: In another AML patient (Figure 4), RHAMM-specific CD8+ T cells were detected by flow cytometry which certainly constituted a distinct subpopulation of RHAMM-specific CD8+ T cells (Figures 4(f) and 4(j)), as proven by a number of negative controls (Figures 4(c)–4(e) and 4(g)–4(i)) including RHAMM-tetramer stained CD8+ cells which were not stimulated by any peptide (Figures 4(e) and 4(i)). Interestingly we observed a general activation of CD8+ T cells at the time of relapse of the patient with no difference of smoldering and progressive disease(Figures 4(a) and 4(b)). This might be due to high concentrations of RHAMM on proliferating malignant cells stimulating specific T-cell responses.


Immune responses to RHAMM in patients with acute myeloid leukemia after chemotherapy and allogeneic stem cell transplantation.

Casalegno-Garduño R, Meier C, Schmitt A, Spitschak A, Hilgendorf I, Rohde S, Hirt C, Freund M, Pützer BM, Schmitt M - Clin. Dev. Immunol. (2012)

RHAMM-specific CTLs are present, but not functional. PBMCs were obtained from an AML patient who received chemotherapy. (a), (b). RHAMM-specific CTLs detected by flow cytometry at the stage of smoldering leukemia (c)–(f) and at the stage of progressive disease (g)–(j) did not release neither IFN-γ (a), nor granzyme B (b) at a level higher than background (no peptide control) as assessed by ELISPOT assays. (c)–(j) Reported frequencies correspond to all cells in the CD3+CD8+ T-cell gate (upper numbers), and to all cells in the lymphocyte gate (lower numbers). (c), (g) Isotype negative control, (d), (h) Non-peptide negative control, stained with an irrelevant tetramer, (e), (i) Non-peptide negative control, stained with RHAMM tetramer, (f), (j) CD8+ T cells were stimulated with RHAMM peptide and stained with RHAMM tetramer.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3375151&req=5

fig4: RHAMM-specific CTLs are present, but not functional. PBMCs were obtained from an AML patient who received chemotherapy. (a), (b). RHAMM-specific CTLs detected by flow cytometry at the stage of smoldering leukemia (c)–(f) and at the stage of progressive disease (g)–(j) did not release neither IFN-γ (a), nor granzyme B (b) at a level higher than background (no peptide control) as assessed by ELISPOT assays. (c)–(j) Reported frequencies correspond to all cells in the CD3+CD8+ T-cell gate (upper numbers), and to all cells in the lymphocyte gate (lower numbers). (c), (g) Isotype negative control, (d), (h) Non-peptide negative control, stained with an irrelevant tetramer, (e), (i) Non-peptide negative control, stained with RHAMM tetramer, (f), (j) CD8+ T cells were stimulated with RHAMM peptide and stained with RHAMM tetramer.
Mentions: In another AML patient (Figure 4), RHAMM-specific CD8+ T cells were detected by flow cytometry which certainly constituted a distinct subpopulation of RHAMM-specific CD8+ T cells (Figures 4(f) and 4(j)), as proven by a number of negative controls (Figures 4(c)–4(e) and 4(g)–4(i)) including RHAMM-tetramer stained CD8+ cells which were not stimulated by any peptide (Figures 4(e) and 4(i)). Interestingly we observed a general activation of CD8+ T cells at the time of relapse of the patient with no difference of smoldering and progressive disease(Figures 4(a) and 4(b)). This might be due to high concentrations of RHAMM on proliferating malignant cells stimulating specific T-cell responses.

Bottom Line: Leukemic blasts overexpress immunogenic antigens, so-called leukemia-associated antigens like the receptor for hyaluronan acid-mediated motility (RHAMM).Results were correlated with the clinical outcome of patients.Immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the outcome of AML/MDS patients.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine III, University of Rostock, 18057 Rostock, Germany.

ABSTRACT
Leukemic blasts overexpress immunogenic antigens, so-called leukemia-associated antigens like the receptor for hyaluronan acid-mediated motility (RHAMM). Persistent RHAMM expression and decreasing CD8+ T-cell responses to RHAMM in the framework of allogeneic stem cell transplantation or chemotherapy alone might indicate the immune escape of leukemia cells. In the present study, we analyzed the expression of RHAMM in 48 patients suffering from acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Furthermore, we correlated transcripts with the clinical course of the disease before and after treatment. Real-time quantitative reverse transcriptase polymerase chain reaction was performed from RNA of peripheral blood mononuclear cells. T cell responses against RHAMM were assessed by tetramer staining (flow cytometry) and enzyme-linked immunospot (ELISPOT) assays. Results were correlated with the clinical outcome of patients. The results of the present study showed that almost 60% of the patients were RHAMM positive; specific T-cells recognizing RHAMM could be detected, but they were nonfunctional in terms of interferon gamma or granzyme B release as demonstrated by ELISPOT assays. Immunotherapies like peptide vaccination or adoptive transfer of RHAMM-specific T cells might improve the immune response and the outcome of AML/MDS patients.

Show MeSH
Related in: MedlinePlus