Dendritic cells in cancer immunotherapy - a short review

Dendritic cells (DCs) are rare leukocytes that are uniquely potent in their recent application to therapeutic cancer vaccines. Isolated DCs loaded with tumour antigen ex vivo and administered as a cellular vaccine have been found to induce protective and therapeutic anti-tumour immunity. In the present report we describe the most common methods of culturing DCs and delivering tumour antigens and we summarise clinical trials of cancer immunotherapy using DCs-based vaccines

Dendritic cells in peripheral blood of patients with breast and lung cancer--a pilot study.

Dendritic cells (DCs) are regarded as the most potent antigen presenting cells that are well suited to activate T cells toward various antigens, such as tumor-associated antigens, due to their costimulatory activity. There is evidence that DCs are of diverse origin, with at least two types of myeloid and lymphoid precursors implicated in their generation. The recent reports demonstrated that the number and function of dendritic cells might change dramatically in cancer patients. In the present study we evaluated the percentage of myeloid and lymphoid DCs in patients with breast cancer, non-small cell lung cancer (NSCLC) and in the healthy donors. The percentage of both DC populations was significantly lower in patients with NSCLC than in the control group. In patients with breast cancer, the number of lymphoid DCs was significantly higher than in NSCLC patients. The obtained results suggest influence of pathological states on host immune system. The decrease in the number of DCs in the peripheral blood from cancer patients may be closely correlated with the type of tumour

Identification of dendritic cells in the blood and synovial fluid of children with Juvenile Idiopathic Arthritis

Childhood chronic arthritis of unknown etiology is known collectively as juvenile idiopathic arthritis (JIA) and consists of heterogeneous subtypes with unique clinical patterns of disease. JIA is the commonest rheumatic disease in children and may still result in significant disability, with joint deformity, growth impairment, and persistence of active arthritis into adulthood. Basic research is rather focused on rheumatoid arthritis, and this lead to small number of publications considering JIA. In this study we examine, by flow cytometry, the expression of dendritic cells (DCs) in the peripheral blood and synovial fluid of children with active JIA in a group of 220 patients. We reveal a significant decrease in the percentage of immature DCs in the blood of patients compared to control children. Surprisingly, we found higher percentages of mature circulating dendritic cells. Both populations of DCs, immature and mature, were accumulated in patients’ synovial fluid. We also confirmed the presence of CD206+/CD209+ in JIA samples, which can represent a population of macrophages with dendritic cells morphology. Our results support the thesis that dendritic cells are crucial in the induction and maintenance of autoimmune response and local inflammation during juvenile idiopathic arthritis. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 1, pp. 188–199

Modification of immunocytochemical ZAP-70 assay for potential clinical application in B-cell chronic lymphocytic leukemia

The ZAP-70 protein is a member of the Syk/ZAP protein tyrosine kinase family, normally expressed in T cells and NK cells but not found in normal, mature B cells. The protein plays a critical role in the initiation of T-cell signaling. Leukemic cells from patients with B-cell chronic lymphocytic leukemia (B-CLL) that expressed nonmutated immunoglobulin V genes were found to express levels of ZAP-70 protein that were comparable to those detected in T cells of healthy adults. The ZAP-70 protein expression can be evaluated by flow cytometry and may be used as a prognostic marker in B-CLL patients. We modified the method of immunocytochemical assessment of ZAP-70 expression. The traditional two-step method with monoclonal anti-ZAP-70 antibody in the first step followed by FITC-conjugated goat anti-mouse IgG was changed for one-step method with monoclonal anti-ZAP-70 antibody labeled by Zenon Alexa Fluor 488. The method is simple and fast. The major advantage of Zenon labeling technique is its compatibility with simultaneous staining of surface antigens. The cells may be earlier immunostained for CD3, CD19 and/or CD5 to compare of the ZAP-70 kinase expression in B and T cells

Dendritic cells in peripheral blood of patients with breast and lung cancer--a pilot study.

Dendritic cells (DCs) are regarded as the most potent antigen presenting cells that are well suited to activate T cells toward various antigens, such as tumor-associated antigens, due to their costimulatory activity. There is evidence that DCs are of diverse origin, with at least two types of myeloid and lymphoid precursors implicated in their generation. The recent reports demonstrated that the number and function of dendritic cells might change dramatically in cancer patients. In the present study we evaluated the percentage of myeloid and lymphoid DCs in patients with breast cancer, non-small cell lung cancer (NSCLC) and in the healthy donors. The percentage of both DC populations was significantly lower in patients with NSCLC than in the control group. In patients with breast cancer, the number of lymphoid DCs was significantly higher than in NSCLC patients. The obtained results suggest influence of pathological states on host immune system. The decrease in the number of DCs in the peripheral blood from cancer patients may be closely correlated with the type of tumour

Ocena związku pomiędzy ekspresją antygenu CD69 na powierzchni limfocytów T i B krwi obwodowej i szpiku kostnego osób chorych na przewlekłą białaczkę limfocytową a wybranymi czynnikami prognostycznymi

Wstęp. Przewlekła białaczka limfocytowa (CLL, chronic lymphocytic leukemia) to monoklonalna limfocytoza B-komórkowa najczęściej rozpoznawana u dorosłych. Powszechnie znanymi czynnikami rokowniczymi tej białaczki są: między innymi stadium zaawansowania klinicznego według skali Raia lub Bineta, czas podwojenia limfocytozy (LDT), poziom kinazy tymidynowej oraz b2-mikroglobuliny. Nadal poszukuje się nowych markerów prognostycznych CLL. Celem pracy była ocena odsetka i bezwzględnej liczby aktywowanych limfocytów B i T krwi obwodowej i szpiku kostnego chorych na CLL oraz ocena korelacji między limfocytami z ekspresją markera CD69 a wybranymi czynnikami prognostycznymi CLL. Materiał i metody. Badaniami objęto 150 osób. Grupę badaną stanowiło 120 nieleczonych chorych na CLL, natomiast grupę kontrolną — 30 zdrowych osób. Od pacjentów z grupy kontrolnej pobrano krew obwodową w celu oceny immunofenotypu limfocytów. Rozpoznanie pacjentów z CLL ustalono na podstawie badania klinicznego, oceny morfologii i immunofenotypu limfocytów krwi obwodowej oraz badania szpiku kostnego. Komórki mononuklearne izolowano z krwi oraz szpiku w celu oceny immunofenotypu metodą cytometryczną. Wyniki. Osoby chore na CLL charakteryzowały się wyższą niż osoby zdrowe liczbą bezwzględną limfocytów B oraz T z ekspresją antygenu CD69. Na podstawie oceny odsetka komórek B CD19+ krwi obwodowej oraz szpiku z ekspresją wczesnego markera aktywacji CD69 wykazano związek ze stadium według Rai. Wykazano również istnienie ujemnej korelacji pomiędzy odsetkiem limfocytów T CD3+CD69+ krwi obwodowej a czasem podwojenia limfocytozy. U chorych, u których doszło do podwojenia limfocytozy, stwierdzono wyższy odsetek limfocytów T CD3+CD69+. Wykazano, że u osób, u których z uwagi na szybką progresję choroby wdrożono leczenie, pojawił się większy odsetek limfocytów B CD19+CD69+ niż u osób nieleczonych. Wnioski. Ocena liczby limfocytów T oraz B z ekspresją antygenu CD69 stanowi cenne uzupełnienie diagnostyki cytometrycznej CLL. Oprócz znanych czynników prognostycznych u chorych należy zlecać ocenę liczby aktywowanych limfocytów, uzyskując w ten sposób pełniejszy obraz kliniczny pacjenta

Evaluation of monocyte-derived dendritic cells, T regulatory and Th17 cells in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors

Immunotherapy with dendritic cells (DC) may constitute a new and advantageous option for patients with chronic myeloid leukemia (CML) who respond to therapy with tyrosine kinase inhibitors (TKI), but do not reach complete cytogenetic or molecular remission. In this study, we evaluated the immunophenotype of DC generated from monocytes (Mo-DC) of patients with CML and the influence of TKI therapy on the results of CML-DC generation. We also measured the percentages of T regulatory cells (Tregs) as well as Th17 cells in 19 untreated patients suffering from CML, and in 28 CML patients treated with TKI. We found that DC can be reliably generated from the peripheral blood CD14+ cells of untreated CML patients. But we observed a persistent expression of CD14 monocyte marker on DC from CML patients, together with lower percentages of Mo-DC with expression of CD1a (p = 0.002), CD80 (p = 0.0005), CD83 (p = 0.0004), and CD209 (p = 0.02) compared to healthy donors. There was an adverse correlation between WBC count and the percentage of Mo-DC with co-expression of CD80 and CD86 (R = –0.63; p = 0.03). In patients treated with TKI, we observed higher efficacy of DC generation in seven-day cultures, compared to untreated patients. Expression of CD209 on DC was higher in patients treated with TKI (0.02). The duration of TKI therapy correlated adversely with MFI for CD1a (R = –0.49; p = 0.006) and positively with MFI for CD83 (R = 0.63; p = 0.01). Percentages of CD4+CD25highFoxP3+ cells (p = 0.0002) and Th17 cells (p = 0.02) were significantly higher in untreated CML patients compared to healthy controls. There was a significant correlation between the percentage of Treg cells and the percentage of peripheral blood basophiles (R = 0.821; p = 0.02). There were no changes in Tregs or Th17 cell percentages in CML patients after six months of TKI therapy. However, the expression of intracellular IL-17 in Th17 cells correlated negatively with the time of TKI therapy in the whole group of treated patients (R = –0.516; p = 0.04). We noted a correlation between IL-6 serum level and peripheral blood WBC count (R = 0.492; p = 0.04). There was also an inverse correlation between the serum level of IL-6 and the duration of TKI therapy (R = –0.66; p = 0.03). Taken together, our data shows that mature DC can be generated from CML patients treated with TKI, and that the yield of Mo-DC is higher in patients treated with TKI than in patients with active disease. This should encourage further trials with DC immunotherapy in patients with cytogenetic response after TKI therapy. We also found increased frequencies of T regulatory and Th17 cells in CML patients, which might suggest their potential role in immunity against this disease. Further studies are needed to determine if manipulation of these cell populations might improve the results of DC immunotherapy. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 1, pp. 153–160