Low expression of costimulatory molecules and mRNA for cytokines are important mechanisms of immunosuppression in acute lymphoblastic leukemia in children?
Mechanisms leading blasts of acute lymphoblastic leukemia to escape from immune surveillance are still unknown. Only few reports showed that ALL cells are inefficient antigen presenting cells. The aim of the study was to assess expression of critical costimulatory/adhesion molecules and mRNA for main pro- and anti-inflammatory cytokines in ALL cells. Children with B-cell precursor ALL (n=20) were prospectively enrolled into the study. Expression of costimulatory/adhesion molecules (CD1a, CD11c, CD40, CD54, CD80, CD83, CD86, CD123, HLA class I and II) was assessed by flow cytometry and mRNA for cytokines (IFN-gamma, IL-10, IL-4, TGF-beta) - with real-time PCR.


RESULTS
1) high expression was observed for HLA I and II class, moderate for CD40, CD83, CD86 and low or no expression for CD80, CD54, CD1a, CD11c and CD123; 2) we found expression of mRNA for IFN-gamma, IL-10, IL-4 and TGF-beta in blasts cells (but not in all specimens). We noted relatively lower expression of all assessed cytokines comparing to T-cells obtained from healthy donors but interestingly expression for IL-10 was higher in normal B-cells than in blast cells, and IFN-gamma and IL-4 were not found in normal B-cells. In summary we suggest that ALL-blasts present low expression of costimulatory/adhesion molecules and mRNA for cytokines and this probably contribute to the absence of host T- cells stimulation to immune response.
Luczyński
W
W
Department of Pediatric Oncology, Medical University of Bialystok, Bialystok, Poland.
Stasiak-Barmuta
A
A
Iłendo
E
E
Kovalchuk
O
O
Krawczuk-Rybak
M
M
Malinowska
I
I
Mitura-Lesiuk
M
M
Chyczewski
L
L
Matysiak
M
M
Kowalczyk
J
J
Jaworowski
R
R
D015703:Antigens, CD / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007108:Immune Tolerance; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology* / Q000378:metabolism*; D011446:Prospective Studies; D012333:RNA, Messenger / Q000378:metabolism
D015703:Antigens, CD; D016207:Cytokines; D012333:RNA, Messenger