Increased Sensitivity to Complement and a Decreased Red Blood Cell Life Span in Mice Mosaic for a Nonfunctional Piga Gene

Tremml, Gabi; Dominguez, Cecilia A.; Rosti, Vittorio; Zhang, Z.; Pandolfi, Pier Paolo; Keller, Peter M.; Bessler, Monica

doi:10.1182/blood.v94.9.2945

Cited by 99 publications

(45 citation statements)

References 36 publications

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“…2 B shows the relative level of PIGA − cells for all four blood cell lineages and the proportion of PIGA − reticulocytes measured at the age of 4 (45%, 34–57%), 8 (53%, 24–74%), and 16 (66%, 33–97%) mo. The proportion of PIGA − red blood cells was significantly lower than PIGA − reticulocytes in all animals analyzed, which is consistent with the shortened half-life of PIGA − red cells in circulation 22. We have previously shown that PIGA − red cells from mice mosaic for a nonfunctional Piga gene have an increased sensitivity to complement 22.…”

Section: Resultssupporting

confidence: 83%

“…The proportion of PIGA − red blood cells was significantly lower than PIGA − reticulocytes in all animals analyzed, which is consistent with the shortened half-life of PIGA − red cells in circulation 22. We have previously shown that PIGA − red cells from mice mosaic for a nonfunctional Piga gene have an increased sensitivity to complement 22. Similarly, also PIGA − red cells from LF mice showed an increased lysis when exposed to complement (data not shown), suggesting that the decreased half-life of PIGA − red cells is due to the action of complement.…”

Section: Resultssupporting

confidence: 82%

“…Thus, our LF mice demonstrate that pancytopenia, in particular thrombocytopenia, which are often found in patients with PNH, are not due to the lack of GPI-linked proteins, but rather caused by the underlying bone marrow failure that accompanies or precedes PNH. In contrast to our previous mouse model for PNH 22, FES-Cre–mediated recombination of the loxPiga allele provides us with mice that due to a somatic mutation in HSCs in the bone marrow have high percentages of PIGA − blood cells in all blood cell lineages. In this respect, LF mice mimic accurately the situation of PIGA − cells in patients with PNH.…”

Section: Discussionmentioning

confidence: 92%

“…1 B). In double transgenic mice, Cre-mediated recombination of the loxPiga allele deletes part of Piga exon 2, which abolishes the function of PIGA (22; Fig. 1 A).…”

Section: Resultsmentioning

confidence: 99%

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Fes-Cre Targets Phosphatidylinositol Glycan Class a (Piga) Inactivation to Hematopoietic Stem Cells in the Bone Marrow

Keller

Payne

Tremml

et al. 2001

The Journal of Experimental Medicine

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A somatic mutation in the X-linked phosphatidylinositol glycan class A (PIGA) gene causes the loss of glycosyl phosphatidylinositol (GPI)-linked proteins on blood cells from patients with paroxysmal nocturnal hemoglobinuria. Because all blood cell lineages may be affected it is thought that the mutation occurs in a hematopoietic stem cell. In transgenic mice, germline transmission of an inactive Piga gene is embryonic lethal. To inactivate the murine Piga gene in early hematopoiesis we therefore chose conditional gene inactivation using the Cre/loxP system. We expressed Cre recombinase under the transcription regulatory sequences of the human c-fes gene. FES-Cre inactivated PIGA in hematopoietic cells of mice carrying a floxed Piga allele (LF mice). PIGA− cells were found in all hematopoietic lineages of definitive but not primitive hematopoiesis. Their proportions were low in newborn mice but subsequently increased continuously to produce for the first time mice that have almost exclusively PIGA− blood cells. The loss of GPI-linked proteins occurred mainly in c-kit+CD34+Lin− progenitor cells before the CFU-GEMM stage. Using bone marrow reconstitution experiments with purified PIGA− cells we demonstrate that LF mice have long-term bone marrow repopulating cells that lack GPI-linked proteins, indicating that recombination of the floxed Piga allele occurs in the hematopoietic stem cell.

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Section: Resultssupporting

confidence: 83%

Section: Resultssupporting

confidence: 82%

Section: Discussionmentioning

confidence: 92%

“…1 B). In double transgenic mice, Cre-mediated recombination of the loxPiga allele deletes part of Piga exon 2, which abolishes the function of PIGA (22; Fig. 1 A).…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Fes-Cre Targets Phosphatidylinositol Glycan Class a (Piga) Inactivation to Hematopoietic Stem Cells in the Bone Marrow

Keller

Payne

Tremml

et al. 2001

The Journal of Experimental Medicine

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“…The mechanism for the expansion is unknown. Nevertheless, both in vitro culture of normal and Pig-a knockout (KO) mouse embryonic stem (ES) cells and in vivo study by generation of Pig-a KO chimaeric mice observed no growth advantage of the abnormal ES cells over the normal cells (Dunn et al, 1996;Kawagoe et al, 1996;Lin et al, 1998;Tremml et al, 1999).…”

mentioning

confidence: 99%

Chimaeric mice with disruption of the gene coding for phosphatidylinositol glycan class A (Pig‐a) were defective in embryogenesis and spermatogenesis

Lin

Yu²,

Huang³

et al. 2000

Br J Haematol

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Summary. Mutations in the gene encoding PIG-A (phosphatidylinositol glycan class A) are found in patients with paroxysmal nocturnal haemoglobinuria (PNH), an acquired haematopoietic stem cell disorder. Individuals with hereditary PIG-A mutations have never been identified, which is also manifested by the difficulties in generating Pig-a knockout (KO) mice. This study investigated the effect of Pig-a mutations on the development of visceral and genital organs in addition to the haematopoietic system by the generation of Pig-a KO chimaeric mice. Of a total of 54 live births out of 1684 blastocysts injected, chimaerism for Pig-a knockout was detected in 29 mice, suggesting the importance of Pig-a in embryogenesis and in live birth. Quantification of the degree of chimaerism in different organs of the surviving chimaeric mice revealed extremely low levels of Pig-a KO cells in the liver and spleen. In contrast, high levels of KO signals were usually detected in the brain, heart, lung and kidney. Haematopoiesis proceeded normally in these chimaeric mice (as measured by`complete blood cell counting') and the Pig-a KO cells were present at low levels in red blood cells and B lymphocytes but at high levels in T lymphocytes, although these KO cells did not gain any growth advantage. The effect of Pig-a knockout was also prominent in the reproductive system, another organ with high mitotic activity. Breeding the male chimaeras revealed a high rate of infertility and abnormality in the male genital organs, including abnormally shaped testes, epididymis and seminal vesicles. Even in the absence of gross abnormalities of the genital organs, low counts of motile sperm were also discernible. Pig-a KO sperm was detected in these organs; however, no transmission of the KO allele was observed. The results suggest a possible mechanism underlying the non-transmission of the Pig-a KO gene in germlines.

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Glycosylphosphatidylinositol-linked proteins are required for maintenance of a normal peripheral lymphoid compartment but not for lymphocyte development

et al. 2002

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Surface proteins tethered to the membrane through a glycosylphosphatidylinositol (GPI) anchor are deficient in the blood cells of patients with paroxysmal nocturnal hemoglobinuria (PNH) as result of a somatic mutation, in a hematopoietic stem cell, of the X‐linked phosphatidylinositolglycan complementation group A (PIG‐A) gene. In PNH patients, compared to the large numbers of GPI‐deficient myeloid cells, the proportion of GPI‐deficient lymphocytes tends to be low, and therefore the impact of GPI deficiency on immune function has been unclear. We have obtained complementation by Pig‐a– embryonic stem (ES) cells of Rag–/– blastocysts, and we show that Pig‐a– ES cells are able to reconstitute the T cell and B cell compartments of Rag–/– mice. Although these mice were immunologically competent, by comparison with appropriate controls we detected several abnormalities: (1) increased levels of IgG; (2) high frequency/titers of anti‐nuclear antibodies; (3) markedly reduced delayed hypersensitivity; and (4) impaired activation‐induced lymphocyte death in vitro. In some cases, aging Pig‐a–/Rag–/– chimeric mice developed lymphadenopathy and polyclonal T cell and B cell expansion. Thus, GPI‐linked proteins are not required for lymphocyte development but they are required for normal lymphocyte function and for maintaining normal peripheral lymphoid homeostasis.

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Increased Sensitivity to Complement and a Decreased Red Blood Cell Life Span in Mice Mosaic for a Nonfunctional Piga Gene

Cited by 99 publications

References 36 publications

Fes-Cre Targets Phosphatidylinositol Glycan Class a (Piga) Inactivation to Hematopoietic Stem Cells in the Bone Marrow

Fes-Cre Targets Phosphatidylinositol Glycan Class a (Piga) Inactivation to Hematopoietic Stem Cells in the Bone Marrow

Chimaeric mice with disruption of the gene coding for phosphatidylinositol glycan class A (Pig‐a) were defective in embryogenesis and spermatogenesis

Glycosylphosphatidylinositol-linked proteins are required for maintenance of a normal peripheral lymphoid compartment but not for lymphocyte development

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