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Biomedical subjects

E A Boyse

Publications and source records attributed to E A Boyse.

At least 19 recordsLinked to original sources
PubMed1992

Adoptive transfer of skin-selective autoimmunity induced by Skn alloantigenic disparities.

Two unlinked genes of the mouse, Skn-1 and Skn-2, each with alterative alleles, specify alternative cell-surface Skn alloantigens expressed only by epidermal and neural cells. C57BL/6 (B6) and A/J (A) strain mice differ at both Skn loci. Thus lethally irradiated B6 mice restored with (B6 x A)F1 hybrid hematopoietic cells [(B6 x A)/B6 chimeras] reject A strain (Skn-incompatible) skin grafts. Our studies were designed primarily to test the inference that (B6 x A)F1 lymphoid cells, after differentiating in B6 recipients, which lack the Skn alloantigens of A strain mice, may make an Skn-related, skin-selective autoimmune response when returned to their native (B6 x A)F1 habitat. Severe cutaneous lesions did, indeed, ensue after spleen cells of (B6 x A)/B6 chimeras were transferred to (B6 x A)F1 recipients, provided that three conditions were met--namely, (i) priming of the (B6 x A)/B6 chimeric donor by grafting and rejection of Skn-incompatible A strain skin grafts, (ii) stimulation of the recipient's skin as from shaving, at which sites the lesions were mainly located, and (iii) pretreatment of the (B6 x A)F1 recipients with cyclophosphamide or sublethal irradiation. Spleen cells of control female chimeras primed by grafting and rejection of H-Y (Skn-compatible) B6 male skin failed to incite the Skn-typical cutaneous lesions in (B6 x A)F1 recipients, indicating that these lesions were Skn-specific and not a nonspecific consequence of incompatible skin grafting per se. Normally compatible A strain skin grafts, but not Skn-compatible B6 skin grafts, were rejected by cyclophosphamide-treated (B6 x A)F1 recipients of (B6 x A)/B6 spleen cells from Skn-primed chimera donors. Treatment of primed chimeras' spleen cells with antiserum to H-2a (A strain) specifically abolished their capacity to adoptively incite the Skn-related autoimmune syndrome, confirming that the immune cells responsible are of (B6 x A)F1 origin and are not residual B6 derivatives. These findings add weight to the status of Skn systems as agents of tissue-selective histoincompatibility and, perhaps, of clinical disorders with a known or suspected autoimmune basis affecting the skin.

Alleles↗
PubMed1992

Phenotypic and functional immaturity of human umbilical cord blood T lymphocytes.

Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that frequently accompanies this procedure. Recent clinical reports have implied that the use of umbilical cord blood as a source of transplantable stem cells may solve these problems. To date, definitive experiments have not been performed to assess the immunological potential of T cells found in umbilical cord blood, which could mediate graft-versus-host disease. In the present study we have observed that umbilical cord blood contains T lymphocytes that appear to be phenotypically immature. In addition, umbilical cord blood lymphocytes appeared to be functionally immature as shown by minimal responses to stimulation with interleukin 2, phytohemagglutinin, or alloantigens. Thus, umbilical cord blood may be more suitable for allogeneic transplantation than bone marrow in that these cord blood cells may not be as capable of mediating graft-versus-host disease.

Animals↗
PubMed1992

Expression of urinary H-2 odortypes by infant mice.

The extended H-2 complex of genes in the mouse includes at least three loci that independently specify distinctive body odors, "odortypes," whose differential recognition influences mating choice and affects the maintenance of early pregnancy. A prime experimental method of identifying H-2 odortypes is the specially designed Y-maze in which mice are trained, by water deprivation and reward, to distinguish odors conducted to the arms of the maze from H-2-dissimilar mice or their urines. It is confirmed that H-2-dissimilar infant mice, unlike adult mice, are not distinguished by trained mice in the Y-maze. However, a previous conclusion that infant mice do not express H-2 odortypes is shown to be incorrect, because the urines of H-2-dissimilar infant mice, even at 1 day of age, were distinguished in the Y-maze. Thus urine, ingested by the mother, clearly could suffice for her to distinguish her own from other H-2-dissimilar pups. Further, urine would seem to be a unique source of H-2 odortypes. If, as we believe, H-2 odortypes represent mostly compound odors composed by H-2 genetic variation in the urinary output of odorous metabolites, as distinct from simple odors that depend on chemical differences of single odorants, then the kidney, which is not responsible for H-2 odortype specificity, may nevertheless impart a unique character to urinary odortypes by virtue of differential excretion/resorption processing of various constituent odorous metabolites. In that case, various organs and tissues, among which the hematopoietic/lymphoid system is known to contribute to H-2 odortype specificity, may exhibit tissue-specific varieties of H-2 odortypes, their products having not yet been subjected to renal processing.

Age Factors↗
PubMed1992

Expression of type IV collagenase correlates with the invasion of human lymphoblastoid cell lines and pathogenesis in SCID mice.

An in vitro model, called the Membrane Invasion Culture System (MICS), was used to study the invasive potential of an Epstein-Barr virus (EBV) positive lymphoblastoid cell line (LCL), an EBV-negative Burkitt lymphoma (BL) cell line of American origin and an EBV-positive BL of African origin. MICS measured the ability of these cell lines to invade reconstituted basement membrane-coated filters, which correlated with their tumorigenic and metastatic capabilities in a SCID mouse model. Furthermore, the significantly greater invasive behaviour of the EBV-positive LCL was directly correlated with the cells' ability to express and secrete human type IV collagenase (72 kDa), an important metalloproteinase responsible for the degradation of collagen IV in basement membranes. The data suggest that MICS and the SCID mouse are useful tests of tumorigenicity in lymphoid cells, with measurable effects in both systems related to human type IV collagenase activity. Both models allow further exploration of malignant phenotypes associated with EBV transformation of lymphoid tissues.

Animals↗
PubMed1991

Umbilical cord blood hematopoietic stem and repopulating cells in human clinical transplantation.

This paper reviews our recent laboratory and clinical studies demonstrating the efficacious use of human umbilical cord blood for HLA-matched allogeneic sibling stem/progenitor cell transplantation in cases of Fanconi's anemia. Future implications and potential problems are discussed with regards to (a) the possibility of maternal cell contamination, (b) the broadness of applicability with regards to other diseases that might be transplanted, and whether such transplants are feasible in adults, as well as in children, and (c) the immunological reactivity of cord blood cells, and whether these cells can be used to cross histocompatibility barriers more easily than that of bone marrow from adults.

Animals↗
PubMed1990

Human umbilical cord blood: a clinically useful source of transplantable hematopoietic stem/progenitor cells.

This is a review and discussion of studies leading to the first use of human umbilical cord blood, material usually discarded, for the provision of stem/progenitor cells for clinical hematopoietic reconstitution. This prospect arose as a result of extensive studies of the harvesting and cryopreservation of cord blood and of its numerical content of progenitor cells demonstrable in vitro. A male patient with Fanconi anemia (FA) was conditioned with a modified regimen of cyclophosphamide and irradiation that accommodates the abnormally high sensitivity to these agents that is characteristic of FA. Cryopreserved cord blood had been retrieved at birth from a female sibling known from prenatal testing to be unaffected by FA and to be human leukocyte antigen (HLA)-compatible with the prospective sibling recipient. After conditioning and therapeutic infusion of thawed cord blood, successful hematopoietic reconstitution was indicated by the general health of the patient, who had previously required supportive transfusions, by satisfactory hematological criteria and by counts of hematopoietic progenitor cells of various types in the bone marrow. Complete engraftment of the myeloid system with donor cells was evident from cytogenetics, ABO typing, study of DNA polymorphisms, and normal cellular resistance to cytotoxic agents that reveal the fragility of FA cells; the blood contained a residuum of host lymphocytes exhibiting chromosomal damage, but the trend has been towards eliminating these damaged cells. This implies that cord blood from a single individual should provide sufficient reconstituting cells for effective hematopoietic repopulation of an autologous or an HLA-compatible allogeneic recipient.

Blood Transfusion↗
PubMed1990

Chemosensory identity and the Y chromosome.

Genes in the extended major histocompatibility complex (MHC) of the mouse (H-2: Qa:T1a) impart to each mouse an odor that reflects its genetic constitution at this region of chromosome 17. Sensory recognition of these differential odors influences reproductive behavior and evokes neuroendocrine responses critical to the maintenance of pregnancy. To determine whether other parts of the mouse genome contribute to individual odor, and so may similarly exert a selective force on loci other than the MHC, mice differing genetically only in their X and/or Y chromosomes were tested for individuality of scent in the Y-maze system previously employed to investigate MHC-related scent distinctions. It was found that the X and Y chromosomes each confer individuality of scent related to genotype, but differences at the H-2 locus are considerably more salient. Nevertheless, chemosensory cues controlled by differences on the Y chromosome could play a role in individual recognition, mate selection, aggressive interactions, and perhaps other aspects of mouse chemosensory behavior.

Animal Communication↗
PubMed1990

Further data on the selective expression of Ly-5 isoforms.

Ly-5 (CD45) glycoproteins of the mouse, expressed by all or most hematopoietic cell lineages and specified by a single Ly-5 gene, range in size from isoform T200 of T cells (the smallest), in which exons 4, 5, and 6 are not represented, to isoform B220 of B cells (the largest), in which all three of these optional exons are represented. The main purpose of the present study, utilizing the polymerase chain reaction (PCR), was to ascertain whether known isoforms of intermediate size are generated by single or dual usage of optional exons 4, 5, and 6. Transcripts representing all eight isoforms predictable from varied use of three exons were observed among a diverse panel of nine B-cell tumors in culture, but there was no evident concordance with known contrasting differential features that distinguish members of the B-cell tumor panel. No two B tumors exhibited the same variety of transcripts and the relative quantities of transcripts expressed varied greatly from tumor to tumor. Cloning of B-cell tumors did not alter their distinctive transcript patterns. Separation methods (sodium dodecyl sulfate polyacrylamide gel electrophoresis; SDS-PAGE) did not suffice to segregate all corresponding expressed isoforms but did establish that transcripts representing usage of a single optional exon and of two optional exons were actually translated, which supports a provisional inference that all eight isoforms exist. The considerable diversity of B-cell transcript phenotypes was not seen among seven T-cell leukemias, two cytolytic T-cell lines, and three Th 1 helper T-cell lines, all of which displayed a uniform phenotype comprising major expression of the T200 transcript (no optional exon) and minor expression of a transcript employing exon 5. However, a panel of five cloned Th2 T-cell lines, which represent a second and functionally different branch of the helper/inducer T-cell category, exhibited a characteristic transcript pattern which distinguished them from a panel of three Th1 T-cell lines. The major transcript in the Th2 lines was also T200, but the Th2 lines showed higher representation of transcripts containing optional exons. A single Th2 clone expressed an unusual transcript suggesting a potential isoform not compounded simply by varied inclusion of the three identified optional exons. After activation of the helper T-cell lines with concanavalin A (Con A), expression of transcripts containing optional exons appeared to decrease.

Animals↗
PubMed1990

Regulation of alternative splicing in the generation of isoforms of the mouse Ly-5 (CD45) glycoprotein.

Alternative splicing generates various Ly-5 glycoprotein isoforms of the cell surface that typify different cell lineages and stages of hematopoietic differentiation in the mouse; exons 4-6 are incorporated to generate a B-cell isoform (B220) and excluded from a T-cell isoform (T200), the other coding exons (3 and 7-33) being shared. As a first step to understanding the mechanisms regulating Ly-5 alternative splicing, and thus determining Ly-5 isoforms, a minigene representing exons 3-7 was transfected into Ly-5-expressor T cells and B cells and into nonexpressor L cells for comparison of splicing patterns. We conclude that all the information required for faithful splice-site selection according to cell type is contained within the resulting pre-mRNA. The splicing pattern manifested by nonexpressor L cells may represent a default and nonregulated type. We postulate trans-acting factor(s) to account for the selection of appropriate exons, and we provide support for this interpretation from analysis of fused hybrid T-B cells, which exhibited B-cell specific Ly-5 transcripts. Splicing patterns were well conserved despite substantial disruption of constructs. However, extensive deletion analyses suggested that cis sequences flanking and within exon 6 affect the exclusion of that exon in T cells.

Animals↗
PubMed1990

Odor types determined by the major histocompatibility complex in germfree mice.

The major histocompatibility complex (MHC) is the prime but not exclusive determinant of genetically specific constitutive body odors, termed odor types, represented strongly in urine of the mouse. Perception of MHC-determined odor types influences reproductive behavior in the contexts of mate choice and maintenance of early pregnancy, tending to favor the propagation of one MHC type over another. How MHC genotype determines MHC odor type is unknown. One possible explanation is that differential odorants are generated by populations of commensal microorganisms whose composition is somehow geared to MHC diversity. This hypothesis was tested in the Y-maze system in which mice are trained to distinguish the urinary odors of MHC-congenic mice. First, it was shown that mice could readily be trained to distinguish the urines of germfree MHC-congenic mice. Second, it was shown that mice trained to distinguish the urines of conventionally maintained MHC-congenic mice could as readily distinguish the urines of germfree MHC-congenic mice. These results imply that MHC-determined odor types do not depend on odorants generated by microorganisms.

Animals↗
PubMed1989

Expression of the Q8/9d gene by T cells of the mouse.

The Q genes, specifying Qa antigens and situated in the extended part of the major histocompatibility complex (MHC) of the mouse, comprise a subgroup of MHC class I genes whose significance and function are still largely unknown. In screening a cDNA library made from the BALB/c inducer T-cell line Cl.Ly1-T1, we isolated 11 clones representing Q8/9, but none representing Q6 or Q7. Confirmatory evidence is given that the Q8/9 gene originated from fusion of the 5' region of the Q8 gene with the 3' region of the Q9 gene at a recombination site or hot spot in the vicinity of intron 4. Contrary to previous impressions that Q8/9 is an inert pseudogene, we find that the Q8/9 gene can be functional and encode a Qa-2, 3 antigen. One variety of the 11 Q8/9 clones isolated lacked exon 5, which encodes the transmembrane domain of class I glycoproteins, and thus may account for secretion of a soluble form of Qa-2, 3 antigen thought to be released by activated T cells.

Amino Acid Sequence↗
PubMed1989

Human umbilical cord blood as a potential source of transplantable hematopoietic stem/progenitor cells.

The purpose of this study was to evaluate human umbilical cord blood as an alternative to bone marrow in the provision of transplantable stem/progenitor cells for hematopoietic reconstitution. Although no direct quantitative assay for human hematopoietic repopulating cells is at present available, the granulocyte-macrophage progenitor cell (CFU-GM) assay has been used with success as a valid indicator of engrafting capability. We examined greater than 100 collections of human umbilical cord blood for their content of nucleated cells and granulocyte-macrophage, erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells, in many cases both before and after cryopreservation. First it was determined that granulocyte-macrophage, erythroid, and multipotential progenitor cells remained functionally viable in cord blood untreated except for addition of anticoagulant for at least 3 days at 4 degrees C or 25 degrees C (room temperature), though not at 37 degrees C, implying that these cells could be satisfactorily studied and used or cryopreserved for therapy after transport of cord blood by overnight air freight carriage from a remote obstetrical service. Granulocyte-macrophage progenitor cells from cord blood so received responded normally to stimulation by purified recombinant preparations of granulocyte-macrophage, granulocyte, and macrophage colony-stimulating factors and interleukin 3. The salient finding, based on analysis of 101 cord blood collections, is that the numbers of progenitor cells present in the low-density (less than 1.077 gm/ml) fraction after Ficoll/Hypaque separation typically fell within the range that has been reported for successful engraftment by bone marrow cells. Another observation of practical importance is that procedures to remove erythrocytes or granulocytes prior to freezing, and washing of thawed cells before plating, entailed large losses of progenitor cells, the yield of unwashed progenitor cells from unfractionated cord blood being many times greater. The provisional inference is that human umbilical cord blood from a single individual is typically a sufficient source of cells for autologous (syngeneic) and for major histocompatibility complex-matched allogeneic hematopoietic reconstitution.

Blood Preservation↗
PubMed1989

Sex-chromosomal odor types influence the maintenance of early pregnancy in mice.

Genetically specified body odors are termed odor types. We showed previously that both the X chromosome and the Y chromosome of the mouse determine differential odor types demonstrable by the behavior of trained mice in the conventional Y-maze test system extensively used in the definition of odor types specified by the major histocompatibility complex (MHC). In the present studies we aimed to ascertain whether perception of X chromosomal and Y chromosomal odor types, like the perception of MHC odor types, exerts a spontaneous influence on reproduction. By making use of reciprocal F1 hybrid males and males of the congenic B6.YAKR strain, males differing solely in their X chromosomes, their Y chromosomes, or both were tested in the conventional pregnancy-block system in which isolated females in early pregnancy are known to be subject to a heightened incidence of failed pregnancy when confronted with the scent of a male whose MHC type differs from that of the missing stud male. As previously established for MHC disparity, perception of X chromosomal disparity or of Y chromosomal disparity between stud and secondary males caused a highly significant rise in the incidence of terminated pregnancy. Thus perception of differential odor types other than those specified by the MHC may also be concerned in aspects of selective reproduction.

Animals↗
PubMed1988

Familial imprinting determines H-2 selective mating preferences.

Inbred male mice typically prefer to mate with females of a different, non-self H-2 haplotype. To determine whether this natural preference is irrevocable or results from familial imprinting, a test system was used which relied on previous observations that B6 males (H-2b) mate preferentially with congenic B6-H-2k rather than B6 females, and B6-H-2k males with B6 females. This preference was reversed in B6 males fostered by B6-H-2k parents and in B6-H-2k males fostered by B6 parents, preference in these cases favoring the same H-2 type. Thus, H-2 selective mating preference is acquired by imprinting on familial H-2 types.

Animals↗
PubMed1988

Structural features of Ly-5 glycoproteins of the mouse and counterparts in other mammals.

The Ly-5 system of the mouse defines a set of transmembrane glycoprotein isoforms (T200, B220, etc) that hallmark various lineages and stages of hematopoietic differentiation. These isoforms are the products of a single Ly-5 gene comprising 34 exons, 32 of them (Exs-3-34) protein-coding and three (Exs-5-7) selectively represented in different isoforms (e.g., all three in isoform B220 but none in isoform T200). Probable structural features of Ly-5 glycoproteins, largely inferred from Ly-5 gene composition, are presented and compared with the rat L-CA and human LCA/T200 systems, which are phylogenetic counterparts of Ly-5 as an index of the extent and nature of structural conservation. The outer (N-terminal) region of the Ly-5 T200 isoform comprises three broadly similar domains (Exs-4, 8, 9) with salient features that jointly favor free interaction with the aqueous environment and are shared by the L-CA and human LCA/T200 systems despite an overall interspecies protein sequence similarity in this region of only about 50%. In the larger B220 isoform this region includes epitopes dictated by the selective exons Exs-5, 6, 7, these being more conserved than the shared exons Exs-4, 8, 9 and no doubt sustaining the differential functions of the respective isoforms. Comparison of the genomic sequences of Ex-5 in the Ly-5 and human systems suggests that a shift in splice donor site accounts for an extra 23 amino acids in the human Ex-5-coding domain, which is the only salient structural difference between the mouse Ly-5 and human systems. The inner extracellular region (Exs-10-16) includes subregions of high variability, but again there are shared salient interspecies similarities such as sites and numbers of Cys residues that imply a conserved, tightly-folded conformation, in contrast to the more open conformation predicted for the outer extracellular region. The transmembrane region (Ex-17) is highly conserved, as is the very large cytoplasmic region (Exs-17-34) which may interact with the plasma membrane but probably does not traverse it.

Amino Acid Sequence↗