Sublocalization of the breakpoints of a t(5;16) in myelodysplasia.

As a first step in characterizing a t(5;16)(q31;p11.2) in a patient with the diagnosis refractory anemia with ring sideroblasts, a cell fusion was carried out between bone marrow cells from the patient and the Chinese hamster cell line A3. Using PCR and FISH analysis on hybrid lines containing the human derivative 16 chromosome, the breakpoints could be mapped between the markers TCF-7 and IL-9 on chromosome 5 and OL-7 and s30A4 on chromosome 16, both regions spanning approximately 1 Mb. Since the breakpoint on 5q has occurred in a region that is frequently deleted in myeloid malignancies, the gene disrupted by this translocation could also be implicated in this aberration.

Multiple minor histocompatibility antigen disparities between a recipient and four HLA-identical potential sibling donors for bone marrow transplantation.

A patient with acute leukemia and her family including four HLA-identical siblings were analyzed to select a donor who was not only HLA- but also minor histocompatibility (mH) antigen compatible for allogeneic bone marrow transplantation (BMT). The HLA-A2 restricted mH antigen-specific HA-1, -2, -4, and -5 cytotoxic T-lymphocyte (CTL) clones were used to type the family members for expression of these mH antigens. The patient and one HLA-identical sibling were compatible for these mH antigens. This sibling was selected as the bone marrow donor. The patient engrafted promptly but developed acute and chronic graft-versus-host disease. To study the presence of other mH antigen disparities between recipient and donor, host-versus-graft CTL lines and clones were generated by stimulation of recipient peripheral blood lymphocytes (PBLs) with donor bone marrow cells, and graft-versus-host CTL lines were generated after BMT by stimulation of PBLs of donor origin with recipient bone marrow cells. These CTL lines were cytotoxic to cells from the bone marrow donor and from the recipient, respectively, and to cells from several other family members. T-cell lines, generated from the patient after BMT by stimulation of recipient-derived PBLs with donor bone marrow cells, exhibited no specific cytotoxicity to donor or recipient cells. Chimerism studies after BMT revealed that the PBLs and T-cell lines generated after BMT were of donor origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Order of human hematopoietic growth factor and receptor genes on the long arm of chromosome 5, as determined by fluorescence in situ hybridization.

A large number of human hematopoietic growth factor and growth factor receptor genes are localized at the long arm of chromosome 5. In this study we have determined the order of the human interleukin-3 (IL3), IL4, IL5, IL9, granulocyte macrophage-colony stimulating factor (GMCSF), and the MCSF receptor (MCSFR) genes by fluorescence in situ hybridization. Genomic lambda-clones were isolated using polymerase chain reaction (PCR)-generated probes and labeled with biotin and/or digoxigenin. These clones were first individually mapped: IL3, IL4, IL5, IL9, and GMCSF to 5q31 and MCSFR to 5q33. For ordering purposes multiple probe combinations were hybridized to metaphase chromosomes and interphase nuclei. The interphase hybridizations were evaluated by image analysis, which also allowed the measurement of the physical distance between the hybridization spots. These mapping results suggest the gene order 5cen-IL3/GMCSF-IL5-IL4-IL9-MCSFR+ ++-qter. The known genomic distance between the IL4 and IL5 genes allowed the estimation of the physical distances between the 5q31-specific genes, demonstrating that they are all within about 1.5 Mb of DNA.

The human interleukin-6 receptor alpha chain gene is localized on chromosome 1 band q21.

The human interleukin-6 receptor alpha chain (IL6R alpha) gene was regionally mapped to chromosome 1 band q21 by fluorescence in situ hybridization. As hybridization probes, partially overlapping lambda clones encompassing 28 kb of the genomic region of the gene were used. These clones were isolated using a polymerase chain reaction (PCR)-generated fragment of the 3' non-coding region of the gene. This localization confirms and extends the provisional assignment of the IL6R alpha gene to chromosome 1, for which a panel of somatic cell hybrids was used.

Factors influencing release of granulocyte-macrophage colony-stimulating activity from human mononuclear phagocytes.

Mononuclear phagocytes play an important role in the regulation of hematopoiesis, not only by producing regulatory monokines such as prostaglandins, tumor necrosis factor and interleukin-1 (IL-1), but also by the production of colony-stimulating activity (CSA). Previously, we have demonstrated that granulocyte-macrophage CSA (GM-CSA) production by mononuclear phagocytes can be induced by IL-1. In the present study, the influence of culture conditions on the production of GM-CSA was studied. It was found that both human sera and fetal bovine sera contain constituents - at present undefined - that induce GM-CSA production. These factors are distinct from IL-1 and lipopolysaccharide. In selected experiments, no GM-CSA-inducing effect of serum was found, suggesting that the effect may be donor-related. GM-CSA release in the presence of serum could be reduced by 40% after incubation of mononuclear phagocytes at low cell concentrations in methylcellulose, indicating that intimate cell-cell contact is an additional factor that enhances GM-CSA release.

Interleukin-1 (22-K factor) induces release of granulocyte-macrophage colony-stimulating activity from human mononuclear phagocytes.

An electrophoretically pure preparation of natural human interleukin-1 (IL-1) was shown to stimulate in vitro colony formation in human bone marrow cultures. Day 4 myeloid cluster-forming cells (CFC), as well as early (day 7) and late (day 10) granulocyte-macrophage colony-forming units (CFU-GM) were stimulated in a dose-dependent fashion. At optimal concentrations of IL-1, the number of day 4 CFC reached 72%, the number of day 7 CFU-GM reached 32%, and the number of day 10 CFU-GM reached 80% of the respective numbers of colonies obtained by addition of crude leukocyte-conditioned medium (LCM). The IL-1-induced stimulatory effect on CFU-GM growth could be completely neutralized by a rabbit anti-IL-1 antiserum. Colony growth was abrogated by depleting the marrow cell suspensions of phagocytic cells prior to IL-1 addition. Conversely, the effect could be reintroduced by addition of marrow-derived adherent cells to bone marrow cell suspensions that had been depleted of both phagocytic and E rosetting T cells. Furthermore, media conditioned by bone marrow-derived adherent cells or by peripheral blood mononuclear phagocytes in the presence but not in the absence of IL-1, stimulated in vitro colony growth of phagocyte-depleted bone marrow cell suspensions. These results indicate that IL-1 induces release of granulocyte-macrophage colony-stimulating activity (GM-CSA) from human mononuclear phagocytes.