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C M Astle

Publications and source records attributed to C M Astle.

11 recordsLinked to original sources
PubMed1991

Lymphoid and erythroid repopulation in B6 W-anemic mice: a new unirradiated recipient.

The W-anemic family of mouse mutants is an important model for studying repopulation in unirradiated recipients. This is the first study of blood lymphoid cell repopulation in adult W-anemic mutants given high doses of marrow cells, and it shows a wide difference in repopulation rates of circulating lymphoid and erythroid cells. This study also offers an improved model for marrow transplantation, using W alleles that are spontaneous mutations on the widely used inbred strain C57BL/6J (B6). Unirradiated B6-W41J/W41J or -W41J/W39J recipients of 2 x 10(6) B6 marrow cells are completely repopulated with donor erythrocytes after 3 months, whereas complete repopulation of lymphocytes requires a year. Surprisingly, the eventual degree of repopulation is independent of the severity of the mutation. The new mutants are not as anemic as the commonly used WBB6F1-W/Wv anemic mutants, they have a much higher ability to form macroscopic spleen colonies (spleen colony-forming units, CFU-S), and B6-W41J/W41J mice are fertile. Nevertheless, lymphoid and erythroid repopulation occur to a similar extent in B6-W41J/W41J or -W41J/W39J and in WBB6F1-W/Wv anemic mutants. Repopulation is more rapid in the latter, but host cells may be damaged by B6 reactions against the WB parent. Avoiding graft-versus-host reactions, hybrid resistance, and similar complications are important advantages in using donors and unirradiated recipients all on the B6 mouse genetic background. Additionally, congenic B6 mice provide a variety of genetic markers, allowing myeloid and lymphoid repopulation to be readily quantitated.

Anemia↗
PubMed1990

Effects of transplantation on the primitive immunohematopoietic stem cell.

Transplantation has strong deleterious effects on the primitive immunohematopoietic stem cells (PSC) from which circulating lymphocytes and erythrocytes are descended. We studied these effects over 300-400 d, testing whether PSC numbers, repopulating abilities, or both, were reduced. Equivalent PSC numbers were estimated in recipients of mixtures of genetically different cells, using the binomial model with covariance. Percentages of lymphocyte and erythrocyte types were closely correlated, as were percentages of either type sampled at intervals of several months. This suggests that the same PSC produced lymphoid and myeloid cells, and that most circulating cells were descended from the same PSC over hundreds of days. Equivalent PSC concentrations were approximately 1/10(5) fresh marrow cells, and were about twofold lower using previously transplanted marrow. However, such marrow repopulated only one-seventh to one-eighth as well as fresh marrow. Apparently, transplantation not only reduces PSC concentrations, but also reduces the repopulating ability per PSC. This may result from excessive stimuli to differentiate that overbalance the stimuli for PSC to replenish themselves.

Analysis of Variance↗
PubMed1989

Numbers and functions of transplantable primitive immunohematopoietic stem cells. Effects of age.

This report introduces a new method in immunology, a use of the binomial formula with covariance to estimate numbers and proliferative patterns of the most primitive lymphoid precursors. We studied the primitive stem cells (PSC) from which most circulating lymphocytes and erythrocytes were descended during 300 to 400 days in recipients of genetically distinguishable marrow mixtures in competitive repopulation. Equivalent PSC concentrations (Eq. PSC Conc. or Conc.) were estimated, with the notion of common PSCs contributing equally in lymphoid and myeloid compartments. Similar estimation was done for common PSCs from which lymphocytes (and erythrocytes) drawn at successive sampling times about 100 days apart were descended. The percentages of lymphocyte and erythrocyte types, P1 and Pe, measured in each recipient were closely correlated, especially after 6 months and later. Close correlations were also found in cells sampled at successive one hundred day intervals, especially after the first. Apparently a few PSCs or their direct descendents produced most of the blood lymphocytes and E, and this production continued for many months. Concentrations of these PSCs (Equivalent PSC concentrations) were about one per 10(5) marrow cells from young donors. This is much lower than previous estimates, probably because our methods focus only on the most interesting precursors, those from which most of the circulating cells were descended. Equivalent PSC concentrations were about two-fold higher in old donors; old marrow produced correspondingly higher P1 and Pe values, but these declined with time. There were also small increases with time in the P1 and Pe values with young donors. To explain the temporal trends, we suggest that excess concentrations of precursors less primitive than PSC are present in old marrow, and their contribution to the differentiated cell population gradually declines. Possibly such precursors, as well as true PSC, proliferate in old donors to compensate for deficiencies that develop with age.

Aging↗
PubMed1988

Number and continuous proliferative pattern of transplanted primitive immunohematopoietic stem cells.

We estimated numbers of transplantable primitive stem cells (PSCs) and found evidence that the same PSC continuously produced circulating erythrocytes and lymphocytes. These estimations used the binomial formula on data from recipients of identical portions of marrow mixtures containing two distinguishable cell types. Analysis of variance was used to compare repeated tests within each recipient. Values of pi s or pi c, probabilities that two independently sampled cells were descended from the same PSC, were also estimated, as this does not require the unverified condition that all PSCs contribute equally to the differentiated cell population. Several months after transplantation, erythrocytes were descended from only a single PSC per 1-2 X 10(5) marrow cells injected, several times rarer than previously reported. Percentages of erythrocyte and lymphocyte types in each recipient were closely correlated, with r values ranging from 0.86 to 0.94, in groups receiving 2-8 X 10(5) marrow cells; apparently the same precursors repopulated both myeloid and lymphoid lines in each recipient, as expected of true PSCs. Our data did not fit the clonal succession model, which predicts sequential activation of new PSCs and deactivation of old. Between 76 and 154 days, differentiated erythrocyte precursors were probably exhausted, with no evidence for new precursor activation or for further change between 154 and 250 days. The percentage of newly produced erythrocytes (reticulocytes) of each donor type varied little when individual recipients were followed between 165 and 295 days after transplantation, and variances within recipients were similar at marrow doses from 8 to 200 X 10(5) cells, further contradicting models of sequential activation and deactivation of PSC clones. Thus, transplanted PSCs were continually active during much of the recipient's lifespan.

Analysis of Variance↗
PubMed1988

The decrease in long-term marrow repopulating capacity seen after transplantation is not the result of irradiation-induced stromal injury.

Marrow cells from nonirradiated F1-W/Wv mice repopulated slightly less well than cells from lethally irradiated recipients. Therefore, avoiding irradiation of recipients did not improve the relative repopulating ability of their marrow cells. In other experiments, F1-W/Wv mice were transplanted by parabiosis with marrow of WBB6F1-+/+ (F1-+/+) mice, avoiding cellular handling and irradiation. Marrow cells transplanted to F1-W/Wv mice by this procedure demonstrated slightly better repopulating ability than did marrow cells transplanted by injection. However, they performed no better than those transplanted by parabiosis to irradiated F1-+/+ recipients. Significant impairment of stromal function after irradiation was not indicated. Apparently, stem cell damage caused by transplantation may have greater importance in causing loss of stem cell replicative potential than effects of irradiation-induced stromal injury.

Animals↗
PubMed1988

Effects of transplantation and age on immunohemopoietic cell growth in the splenic microenvironment.

Intact spleens from young adult and aged mice were transplanted into young recipients to compare effects of age and effects of spleen transplantation on hemopoietic and immune functions. Hemopoietic functions of histocompatible spleen transplants were assessed by partial cures of genetically anemic WBB6F1-Sl/Sld recipients, and immune functions were measured as numbers of anti-SRBC PFC(sheep red blood cell plaque-forming cells) and responses to the mitogen PHA (phytohemagglutinin). Spleens from WCB6F1 and WBB6F1 donors at least 28 months old partially corrected anemias in 10 of 28 Sl/Sld recipients, whereas spleens from 5- to 10-month-old donors performed significantly better, partially correcting anemias in 22 of 31 Sl/Sld recipients. B6D2F1 spleens were transplanted from either old or young donors in B6D2F1 recipients to test their ability to support immune-responsive cells. These spleen grafts were much smaller than recipient spleens and contained few anti-SRBC PFC. In contrast WCB6F1-+/+ spleens transplanted in Sl/Sld recipients were much larger, weighing more than the intact spleens of the recipients. Nevertheless when these spleens were from young donors, they contained only about 10% as many anti-SRBC PFC and PHA-responsive cells as did recipient spleens, whereas old donor spleens contained even fewer. Use of splenectomized Sl/Sld recipients did not alter these results. Apparently the effect of transplantation was much more important than age in reducing the spleens' abilities to support immune-responsive cells.

Aging↗
PubMed1979

Processing by the thymus is not required for cells that cure and populate W/WV recipients.

Adult marrow, fetal liver or nu/nu mouse marrow from histocompatible donors was grafted into genetically anemic W/WV recipients, and all three types of grafts cured thymectomized as well as intact W-anemic recipients. With the latter two types of graft, the genetic anemia was cured by cells that could not have been processed in a mature thymus, since the adult recipients were thymectomized before receiving the grafts, the nu/nu donors were congenitally thymusless, and the fetal donors were used at 16 days of gestation. Chromosome-marked marrow grafts were used to show that immune systems were populated to similar degrees in thymectomized and intact W/WV recipients. Therefore, the cells derived from the donor marrow graft that partially populate the immune systems of W-anemic recipients do not require thymus processing. Small numbers of liver rudiment or yolk sac cells from fetal donors less than 12 days old failed to cure W/WV recipients, even when mixed with adult thymus cells. Therefore, the lack of adequately developed thymic helper cells appears not to be the reason why early fetal hemopoietic stem cells fail to cure W/WV recipients.

Aging↗
PubMed1978

Loss of proliferative capacity in immunohemopoietic stem cells caused by serial transplantation rather than aging.

Marrow stem cell lines from old donors and those from young controls gave equally rapid rates of colony growth on spleens of irradiated mice. Old and young stem cell lines competed equally well with chromosomally marked marrow stem cells from a young donor in producing cell types that are stimulated by bleeding; old cells competed 70% as well as young in producing cell types stimulated by phytohemagglutinin (PHA) in vitro. After a single serial transplantation, the rates of colony growth declined 1.5- to 2.5-fold, and the ability to compete declined 2- to 4-fold for bleeding-stimulated and 4- to 10-fold for PHA-stimulated cells. Thus, immediate stem cell proliferative capacities decline much more after one serial transplantation than after a lifetime of normal function.

Animals↗
PubMed1977

Cell lines from old immunodeficient donors give normal responses in young recipients.

Two different immune responses were compared in spleen cells obtained from old and young CBA/HT6J mice. Spleen cells from old mice (23 to 33 months) responded about half as well as did spleen cells from young mice (4 to 10 months) in the adoptive transfer anti-sheep red blood cell (SRBC) plague-forming assay, and caused slightly less than half the uptake of tritiated thymidine in response to phytohemagglutinin (PHA) in vitro. Marrow stem cell from some of the old and young mice whose splenic immune responses were tested were transplanted into irradiated young CBA/CaJ recipients. Seven to 17 weeks later these same immune responses were tested in the spleen cells of these young recipients, and the T6 chromosome marker was used to identify donor cells. Old animals' responses varied greatly, perhaps due to suppressing cells or factors in some individuals. Therefore, cells were never pooled and the responses of receipients were compared to the responses of the donor whose marrow had populated them. The response for a particular old donor, or for the recipients of its stem cells, was divided by the response for the young control used with that donor, or for its stem cell recipients. This was called the old/young ratio. With original donors with an old/young ratio for the SRBC response of (mean +/- S.D.) 0.35 +/- 0.14, The old/young ratio for that same response in the recipients was significantly improved to 1.26 +/- 0.71. In original donors with an old/young ratio for the PHA response of 0.44 +/- 0.17, the old/young ratio in the recipients improved significantly to 0.86 +/- 0.27. Thus, little or none of the decline with age in these immune responses was intrinsic to the old lymphoid stem cells.

Aging↗
PubMed1976

Population of lymphoid tissues in cured W-anemic mice by donor cells.

The percentages of donor cells in lymphoid organs of cured W-anemic mice were determined by using donors with the T6 chromosome marker. W-anemic recipients of two different genotypes were cured by marrow or spleen grafts from histocompatible normal T6/T6 or T6/+ donors. After 2 to 10 months, almost all proliferating cells in the thymuses and marrows, and approximately 75% in the spleens of cured mice were of donor type. However, only 30-40% of the proliferating cells in recipient lymph nodes and 10-20% in their Peyer's patches were of donor type. Percentages of donor cells in marrows and spleens remained high hemopoietic cell division was stopped by injections of erythrocytes. All tissues were slightly less repopulated by donor cells in W-anemic recipients cured by spleen cells compared with those cured by marrow cells. These results were not altered by matching recipients and donors to avoid possible graft versus host reactions, or by removing the thymus of a recipient before it was cured. The fact that the repopulating cells are not all donor type suggests that there are at least two classes of precursor cells that populate the immune system of W-anemic mice, and that not all classes are derived from the grafted cells. Cured W-anemic mice may provide a unique system in which different types of precursor cells of the lymphoid system can be distinguished.

Anemia, Macrocytic↗