scholarly journals Anti-HEL cell monoclonal antibodies recognize determinants that are also present in hemopoietic progenitors

Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 326-334
Author(s):  
T Papayannopoulou ◽  
M Brice ◽  
T Yokochi ◽  
PS Rabinovitch ◽  
D Lindsley ◽  
...  

The characteristics of nine monoclonal antibodies (MoAbs) produced using the uninduced cells of a human erythroleukemia line (HEL) as immunogen are described. These antibodies were grouped into four categories by their differences in recognition of normal cells and cells of hemopoietic cell lines. The four MoAbs of group A recognize determinants that are expressed in a large proportion of normal bone marrow cells and other mature cells. The two MoAbs of group B (53/5, 53/6) and the two MoAbs of group C (54/23, 54/39) recognize small proportions of bone marrow cells, whereas the single MoAb of group D (53/10) essentially recognizes only HEL cells. Competition experiments revealed two pairs of competing Abs (53/5 and 53/6; 54/23 and 54/39). In complement-dependent cytotoxicity of progenitors, 53/6 produced 90%- 100% inhibition of CFU-E, BFU-E, and CFU-C growth; 54/39 30%–60% inhibition of BFU-E and CFU-C growth; 53/10 produced a variable degree of inhibition of CFU-E and BFU-E. Cell sorting using 53/6 resulted in approximately a 10–12-fold enrichment of CFU-E, BFU-E, and CFU-C among the positive cells. Cell sorting with 54/23 resulted in recovery of over 90% of BFU-E and 100% of CFU-C among the 23.5% of sorted cells showing strong or intermediate positivity. These findings suggest that HEL cells possess surface characteristics that are expressed in several classes of hemopoietic progenitors.

Blood ◽  
1984 ◽  
Vol 63 (2) ◽  
pp. 326-334 ◽  
Author(s):  
T Papayannopoulou ◽  
M Brice ◽  
T Yokochi ◽  
PS Rabinovitch ◽  
D Lindsley ◽  
...  

Abstract The characteristics of nine monoclonal antibodies (MoAbs) produced using the uninduced cells of a human erythroleukemia line (HEL) as immunogen are described. These antibodies were grouped into four categories by their differences in recognition of normal cells and cells of hemopoietic cell lines. The four MoAbs of group A recognize determinants that are expressed in a large proportion of normal bone marrow cells and other mature cells. The two MoAbs of group B (53/5, 53/6) and the two MoAbs of group C (54/23, 54/39) recognize small proportions of bone marrow cells, whereas the single MoAb of group D (53/10) essentially recognizes only HEL cells. Competition experiments revealed two pairs of competing Abs (53/5 and 53/6; 54/23 and 54/39). In complement-dependent cytotoxicity of progenitors, 53/6 produced 90%- 100% inhibition of CFU-E, BFU-E, and CFU-C growth; 54/39 30%–60% inhibition of BFU-E and CFU-C growth; 53/10 produced a variable degree of inhibition of CFU-E and BFU-E. Cell sorting using 53/6 resulted in approximately a 10–12-fold enrichment of CFU-E, BFU-E, and CFU-C among the positive cells. Cell sorting with 54/23 resulted in recovery of over 90% of BFU-E and 100% of CFU-C among the 23.5% of sorted cells showing strong or intermediate positivity. These findings suggest that HEL cells possess surface characteristics that are expressed in several classes of hemopoietic progenitors.


Blood ◽  
1988 ◽  
Vol 71 (6) ◽  
pp. 1633-1640
Author(s):  
LM Pelus ◽  
PS Gentile

Intravenous (IV) injection of 0.1 to 10 micrograms of authentic prostaglandin E2 (PGE2) in intact steady-state mice induces a population of bone marrow and spleen cells having the capacity to suppress CFU-GM proliferation when admixed with normal bone marrow cells. Equivalent suppression of CFU-GM committed to monocytic as well as granulocytic differentiation was observed using colony-stimulating factors (CSFs) differing in their lineage specificities and by direct morphological analysis of proliferating clones. Kinetic analysis indicates that suppressive bone marrow cells appear within 2 hours after PGE2 injection, are maximal at 6 hours, and are no longer observed by 24 hours postinjection. Positive and negative selection studies using monoclonal antibodies indicate that the PGE2-induced suppressor cells react positively with anti-GMA 1.2, MAC1, and F4/80 monoclonal antibodies, suggesting a myeloid/monocytic origin. As few as 1,000 positively selected bone marrow or spleen cells were able to inhibit maximally normal CFU-GM proliferation by 50,000 control bone marrow cells. Suppression of normal CFU-GM can be substituted for by 24- hour cell-free supernates from unseparated bone marrow cells or GMA 1.2 or F4/80 positively selected marrow or spleen cells from PGE2-treated but not control mice. These supernates also inhibited BFU-E proliferation. Injection of as few as 2 million bone marrow cells from PGE2-treated mice into steady-state mice or animals hematopoietically rebounding following a sublethal injection of cyclophosphamide significantly suppressed total CFU-GM proliferation in recipient mice within 6 hours. In summary, these studies describe the detection of a novel hematopoietic control network induced by PGE2 in intact mice.


Blood ◽  
1988 ◽  
Vol 71 (6) ◽  
pp. 1633-1640 ◽  
Author(s):  
LM Pelus ◽  
PS Gentile

Abstract Intravenous (IV) injection of 0.1 to 10 micrograms of authentic prostaglandin E2 (PGE2) in intact steady-state mice induces a population of bone marrow and spleen cells having the capacity to suppress CFU-GM proliferation when admixed with normal bone marrow cells. Equivalent suppression of CFU-GM committed to monocytic as well as granulocytic differentiation was observed using colony-stimulating factors (CSFs) differing in their lineage specificities and by direct morphological analysis of proliferating clones. Kinetic analysis indicates that suppressive bone marrow cells appear within 2 hours after PGE2 injection, are maximal at 6 hours, and are no longer observed by 24 hours postinjection. Positive and negative selection studies using monoclonal antibodies indicate that the PGE2-induced suppressor cells react positively with anti-GMA 1.2, MAC1, and F4/80 monoclonal antibodies, suggesting a myeloid/monocytic origin. As few as 1,000 positively selected bone marrow or spleen cells were able to inhibit maximally normal CFU-GM proliferation by 50,000 control bone marrow cells. Suppression of normal CFU-GM can be substituted for by 24- hour cell-free supernates from unseparated bone marrow cells or GMA 1.2 or F4/80 positively selected marrow or spleen cells from PGE2-treated but not control mice. These supernates also inhibited BFU-E proliferation. Injection of as few as 2 million bone marrow cells from PGE2-treated mice into steady-state mice or animals hematopoietically rebounding following a sublethal injection of cyclophosphamide significantly suppressed total CFU-GM proliferation in recipient mice within 6 hours. In summary, these studies describe the detection of a novel hematopoietic control network induced by PGE2 in intact mice.


Biomaterials ◽  
1998 ◽  
Vol 19 (21) ◽  
pp. 1963-1972 ◽  
Author(s):  
Manfred R. Koller ◽  
Mahshid A. Palsson ◽  
Ilana Manchel ◽  
Robert J. Maher ◽  
Bernhard Ø. Palsson

Blood ◽  
1997 ◽  
Vol 90 (9) ◽  
pp. 3444-3455 ◽  
Author(s):  
Anastasia Guerriero ◽  
Lydia Worford ◽  
H. Kent Holland ◽  
Gui-Rong Guo ◽  
Kevin Sheehan ◽  
...  

Abstract We have previously characterized stromal progenitor cells contained in fetal bone marrow by fluorescence-activated cell sorting (FACS) using the differential expression of CD34, CD38, and HLA-DR, and found that a small number were contained within the CD34+ cell fraction. In the present study, the frequency of stromal progenitors in both the CD34+ and CD34− subpopulations from samples of fetal and adult bone marrow was approximately one in 5,000 of the mononuclear cell fraction. Using multiparameter single-cell sorting, one in 20 fetal bone marrow cells with the CD34+, CD38−, HLA-DR−, CDw90+ phenotype were clonogenic stromal progenitors, whereas greater than one in five single cells with the CD34−, CD38−, HLA-DR−, CDw90+ phenotype formed stromal cultures. We found that cultures initiated by hematopoietic and stromal progenitors contained within the CD34+ fraction of bone marrow cells formed mixed hematopoietic/stromal cell cultures that maintained the viability of the hematopoietic progenitor cells for 3 weeks in the absence of added hematopoietic cytokines. We characterized some of the hematopoietic cytokines synthesized by stromal cultures derived from either CD34+ or CD34− bone marrow cells using reverse transcriptase–polymerase chain reaction (RT-PCR) amplification of interleukin-3 (IL-3), stem cell factor (SCF), CD34, Flt3/Flk2 ligand (FL), and thrombopoietin (TPO) mRNA sequences. We found ubiquitous expression of TPO mRNA in greater than 90% of stromal cultures initiated by either CD34+ or CD34− cells, and variable expression of SCF, FL, and CD34 mRNA. In particular, SCF and CD34 mRNA were detected only in stromal cultures initiated by CD34+ bone marrow cells, although the differences between CD34+ and CD34− stromal cells were not statistically significant. IL-3 mRNA was not found in any stromal cultures. An enzyme-linked immunosorbent assay (ELISA) of soluble SCF and TPO present in culture supernatants demonstrated that biologically significant amounts of protein were secreted by some cultured stromal cells: eight of 16 samples of conditioned media from stromal cultures initiated by fetal and adult bone marrow contained more than 32 pg/mL SCF (in the linear range of the ELISA), with a median value of 32 pg/mL (range, 9 to 230), while 13 of 24 samples of conditioned media had more than 16 pg/mL TPO (in the linear range of the ELISA), with a median of 37 pg/mL (range, 16 to 106). Our data indicate that stromal cultures initiated by single bone marrow cells can make FL, SCF, and TPO. Local production of early-acting cytokines and TPO by stromal cells may be relevant to the regulation of hematopoietic stem cell self-renewal and megakaryocytopoiesis in the bone marrow microenvironment.


Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 1977-1986 ◽  
Author(s):  
Peter A. McSweeney ◽  
Katherine A. Rouleau ◽  
Philip M. Wallace ◽  
Benedetto Bruno ◽  
Robert G. Andrews ◽  
...  

Abstract Using a polyclonal antiserum against canine CD34, we previously found that CD34 is expressed on canine bone marrow progenitor cells in a manner analogous to that found in humans. To further characterize CD34+ cells and to facilitate preclinical canine stem cell transplant studies, monoclonal antibodies (MoAbs) were raised to CD34. A panel of 10 MoAbs was generated that reacted with recombinant CD34 and with CD34+ cell lines and failed to react with CD34− cell lines. Binding properties of five purified MoAbs were determined by BIAcore analysis and flow cytometric staining, and several MoAbs showed high affinity for CD34. Two antibodies, 1H6 and 2E9, were further characterized, and in flow cytometry studies typically 1% to 3% of stained bone marrow cells were CD34+. Purified CD34+ bone marrow cells were 1.8- to 55-fold enriched for colony-forming unit–granulocyte-macrophage and for long-term culture initiating cells as compared with bone marrow mononuclear cells, whereas CD34− cells were depleted of progenitors. Three autologous transplants were performed with CD34+ cell fractions enriched by immunomagnetic separation. After marrow ablative total body irradiation (920 cGy), prompt hematopoietic recovery was seen with transplanted cell doses of ≤1.1 × 107 /kg that were 29% to 70% CD34+. Engraftment kinetics were similar to those of dogs previously transplanted with approximately 10- to 100-fold more unmodified autologous marrow cells. This suggests that CD34+ is a marker not only of canine bone marrow progenitors but also for cells with radioprotective or marrow repopulating function in vivo. MoAbs to CD34 will be valuable for future studies of canine hematopoiesis and preclinical studies concerning stem cell transplantation, gene therapy, and ex vivo progenitor cell expansion.


2002 ◽  
Vol 8 (4) ◽  
pp. 615-626 ◽  
Author(s):  
P.J. ter Brugge ◽  
R. Torensma ◽  
J.E. De Ruijter ◽  
C.G. Figdor ◽  
J.A. Jansen

Blood ◽  
1998 ◽  
Vol 91 (6) ◽  
pp. 1977-1986 ◽  
Author(s):  
Peter A. McSweeney ◽  
Katherine A. Rouleau ◽  
Philip M. Wallace ◽  
Benedetto Bruno ◽  
Robert G. Andrews ◽  
...  

Using a polyclonal antiserum against canine CD34, we previously found that CD34 is expressed on canine bone marrow progenitor cells in a manner analogous to that found in humans. To further characterize CD34+ cells and to facilitate preclinical canine stem cell transplant studies, monoclonal antibodies (MoAbs) were raised to CD34. A panel of 10 MoAbs was generated that reacted with recombinant CD34 and with CD34+ cell lines and failed to react with CD34− cell lines. Binding properties of five purified MoAbs were determined by BIAcore analysis and flow cytometric staining, and several MoAbs showed high affinity for CD34. Two antibodies, 1H6 and 2E9, were further characterized, and in flow cytometry studies typically 1% to 3% of stained bone marrow cells were CD34+. Purified CD34+ bone marrow cells were 1.8- to 55-fold enriched for colony-forming unit–granulocyte-macrophage and for long-term culture initiating cells as compared with bone marrow mononuclear cells, whereas CD34− cells were depleted of progenitors. Three autologous transplants were performed with CD34+ cell fractions enriched by immunomagnetic separation. After marrow ablative total body irradiation (920 cGy), prompt hematopoietic recovery was seen with transplanted cell doses of ≤1.1 × 107 /kg that were 29% to 70% CD34+. Engraftment kinetics were similar to those of dogs previously transplanted with approximately 10- to 100-fold more unmodified autologous marrow cells. This suggests that CD34+ is a marker not only of canine bone marrow progenitors but also for cells with radioprotective or marrow repopulating function in vivo. MoAbs to CD34 will be valuable for future studies of canine hematopoiesis and preclinical studies concerning stem cell transplantation, gene therapy, and ex vivo progenitor cell expansion.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4831-4831
Author(s):  
Irene Caliendo ◽  
Rosanna Di Concilio ◽  
Paolo Danise ◽  
Anna Guerriero ◽  
Anna Maria Aurino ◽  
...  

Abstract Abstract 4831 Introduction Previous studies showed that chromosomal and genomic aberrations leading to activation of oncogenes or haploisufficiency of tumor suppressor genes are well-known pathogenic mechanisms in cancer. Additional copies of chromosme 21 are frequently found in Myelodisplastic Syndrome (MDS) and in Acute Myeloid Leukemia (AML); the presence of these chromosomal abnormalities and the high incidence of acute leukemias in subjects with constitutional trisomy 21, suggest that genes on chromosome 21, including RUNX1/AML1, play a particular role in leukemogenesis and hematopoiesis. We describe a patient with syndromic trombocytopenia ( average platelet count= 70000/mm3), psychomothor delay, microcephaly and low stature, that developed a progressive anemia and became transfusion-dependent at seventeen years of age. Materials and methods Cytogenetic analysis was performed on bone marrow cells and on peripheral blood lymphocytes, with standard techniques and evaluated with Giemsa-trypsin-Giemsa banding according to International System for Human Cytogenetic Nomenclature (ISCN 2005). Fluorescent In Situ Hybridization (FISH) experiments was performed on bone marrow samples with LSI AML1/ETO Dual Color, Dual Fusion Translocation and, at the same time, the High-resolution oligo array-CGH (Agilent Human Genome CGH Microarray 44B) was performed on the DNA of the patient. Results The bone marrow cells showed marked dysplastic morphology and the following abnormal karyotype: 46,XX[14]/47,XX,+21[6]; the peripheral blood karyotype was normal. The High-resolution oligo array-CGH demonstrated a constitutional de novo microdeletion of one chromosome 21. The interstitial deletion was found to be approximately 4,4Mb (Megabases), extending from 32,29 Mb to 36,51 Mb on band 21q22.11-12, involving MRAP, IFNAR2, IFNGRR2, KCNE2, KCNE1 and RUNX1 genes. The FISH performed on bone marrow cells, revealed two orange signals representing normal copies of ETO and one green signal for AML1 in 60% interphase cells and two orange signals and two green signals in the remaining 40% cells. The first pattern of signals, for AML1, is related to cells with karyotype 46,XX, while the second pattern of signals is related to cells with karyotype 47,XX,+21. These results indicate that in the myelodisplastic clone the third chromosome 21 are not deleted on band 21q22. Conclusion Three cases were recently published of syndromic thrombocytopenia with 21q22 constitutional deletion, including RUNX1, and variable degree of dysmorphic features and mental delay. One of the three patients developed LMA at the age of six years. Our results further support the fundamental role, in the pathogenetic mechanism of syndromic trombocytopenia and MDS/AML, of the numerical abnormalities of chromosome 21 associated with submicroscopic rearrangement of RUNX1 and other dosage-sensitive unknown genes on chromosome 21. Disclosures No relevant conflicts of interest to declare.


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