[Preimplantation genetic diagnosis (PGD) in carriers of chromosomal translocations: possibilities and results]. / Moznosti a výsledky preimplantacní genetické diagnostiky (PGD) u páru s chromozomální translokací.

AIM OF THE STUDY: To assess the PGD results in couples with robertsonian and reciprocal translocations. DESIGN: Retrospective study. SETTING: Sanatorium Pronatal, Prague, accredited IVF unit. METHODS: 94 infertile couples with translocation (44 couples with robertsonian and 50 couples with reciprocal translocations) were included in the study. The mean woman's age was not different: 33 +/- 4,4 in robertsonian vers. 33 +/- 3.9 in reciprocal translocations. The performance of FISH probes in specific cases was tested on patient's lymfocytes before the treatment was started. After ovarian stimulation (recombinant FSH or hMG + GnRH agonist, "long" protocol) and transvaginal oocyte pick-up, embryo biopsy of a single cell was performed 72 hours after fertilization. After blastomere fixation, translocated chromosomes + chromosomes 13, 18, 21, X and Y were tested using FISH. The maximum of two embryos euploid for detected chromosomes were transferred, supernumerary euploid embryos were frozen. RESULTS: From the total number of 629 embryos, 126 embryos (21.9%) were detected as normal or with balanced translocation--25.2% (68/270) in couples with robertsonian and 16.4% (59/359) with reciprocal translocation. Embryotransfer was performed in 30 cycles (68.2%) in robertsonian and 27 (54%) in reciprocal translocations. 24 pregnancies were achieved--15 (39% per cycle and 50% per ET) for robertsonian and 9 (19% per cycle and 33% per ET) for reciprocal translocation--this difference was statistically significant (p = 0.033). Only one pregnancy in each group ended as abortion. SUMMARY: IVF is a valuable option for couples with infertility problems and translocation. This technique allows in short-term a conception and delivery of a healthy baby with general better prognosis for couples with robertsonian translocation.

T-cell proliferative response is controlled by loci Tria4 and Tria5 on mouse chromosomes 7 and 9.

Lymphocytes of mouse strains BALB/cHeA (BALB/c) and STS/A (STS) differ in their response to CD3 antibody (anti-CD3). We analyzed the genetic basis of this strain difference, using the Recombinant Congenic Strains (RCS) of the BALB/c-c-STS/Dem (CcS/Dem) series. Each of the 20 CcS/Dem strains carries a different, random combination of 12.5% genes from the nonresponding strain STS and 87. 5% genes of the intermediate responder strain BALB/c. Differences in the magnitude of anti-CD3-induced response among CcS/Dem strains indicated that in addition to Fcgamma receptor 2 (Fcgr2) other genes are involved in the control of this response as well, and we have already mapped loci Tria1 (T cell receptor-induced activation 1), Tria2, and Tria3. In order to map additional Tria genes, we tested F2 hybrids between the high responder RC strain CcS-9 and the low responder strain CcS-11. Proliferation in complete RPMI medium without anti-CD3 is controlled by locus Sprol1 (spontaneous proliferation 1) linked to the marker D4Mit23 on Chr 4. At concentration 0.375 microg/ml anti-CD3 mAb, the response was controlled by a locus Tria4, which maps to the marker D7Mit32 on Chr 7. The response to the higher concentration of mAb, 3 microg/ml, was controlled by Tria5, which mapped to the marker D9Mit15 on Chr 9. Anti-CD3 is being used for modulation of lymphocyte functions in transplantation reactions and in cancer treatment. Study of mechanisms of action of different Tria loci could lead to better understanding of genetic regulation of these reactions.

The production of two Th2 cytokines, interleukin-4 and interleukin-10, is controlled independently by locus Cypr1 and by loci Cypr2 and Cypr3, respectively.

The strains BALB/cHeA (BALB/c) and STS/A (STS) differ in production of IL-4 and IL-10, two Th2 cytokines, after stimulation of spleen cells with Concanavalin A, STS being a low and BALB/c a high producer. We analyzed the genetic basis of this strain difference using the recombinant congenic (RC) strains of the BALB/c-c-STS/Dem (CcS/Dem) series. This series comprises 20 homozygous strains. Each CcS/Dem strain contains a different, random set of approximately 12. 5% genes of the "donor" strain STS and approximately 87.5% of the "background" strain BALB/c. We selected for further analysis the RC strain production intermediate between BALB/c and STS. In (CcS-20xBALB/c)F2 hybrids we found that different loci control expression of IL-4 and IL-10. Cypr1 (cytokine production 1) on chromosome 16 near D16Mit15 controls IL-4 production, whereas the production of IL-10 is influenced by loci Cypr2 near D1Mit14 and D1Mit227 on chromosome 1 and Cypr3 marked by D5Mit20 on chromosome 5. In addition, the relationship between the level of these two cytokines depends on the genotype of the F2 hybrids at a locus cora1 (correlation 1) on chromosome 5. This differential genetic regulation may be relevant for the understanding of biological effects of T-helper cells in mice of different genotypes.

IL-2-induced proliferative response is controlled by loci Cinda1 and Cinda2 on mouse chromosomes 11 and 12: a distinct control of the response induced by different IL-2 concentrations.

Lymphocytes of mouse strains BALB/cHeA (BALB/c) and STS/A (STS) differ in the IL-2-induced proliferative response, STS being a high and BALB/c a low responder in the range of concentrations 125-2000 IE/ml. We analyzed the genetic basis of this strain difference using the recombinant congenic (RC) strains of the BALB/c-c-STS/Dem (CcS/Dem) series. This series comprises 20 homozygous strains all derived from two parental inbred strains: the "background" strain BALB/c and the "donor" strain STS. Each CcS/Dem strain contains a different, random set of approximately 12.5% genes of the donor strain STS and approximately 87.5% genes of the background strain BALB/c. In this way, the STS genes controlling the IL-2-induced response became separated into individual CcS/Dem strains, as indicated by differences in the magnitude of the IL-2-induced response among CcS/Dem strains (M. Lipoldová et al., 1995, Immunogenetics 41: 301-311). To map some of these genes, we tested F2 hybrids between one of the high-responder RC strains, CcS-4, and the low-responder parental strain BALB/c. We found that the response to high IL-2 concentrations is controlled by a locus, Cinda1 (cytokine-induced activation 1), on chromosome 11 near the marker D11Mit4. The response to a lower dose of IL-2 tested on lymphocytes of the same mice was found to be controlled by another locus, Cinda2, in the centromeric part of chromosome 12, the higher response being linked to the STS allele of the marker D12Mit37. Understanding the action of genetic factors, such as Cinda1 and Cinda2, that control T cell function is expected to contribute to the efficient analysis of the genetic control of susceptibility to infections and autoimmune diseases.

Separation of multiple genes controlling the T-cell proliferative response to IL-2 and anti-CD3 using recombinant congenic strains.

T lymphocytes of the strain BALB/cHeA exhibit a low proliferative response to IL-2 and a high response to the anti-CD3 monoclonal antibodies, while the strain STS/A lymphocyte response to these stimuli is the opposite. We analyzed the genetic basis of this strain difference, using a novel genetic tool: the recombinant congenic strains (RCS). Twenty BALB/c-c-STS/Dem (CcS/Dem) RCS were used, each containing a different random set of approximately 12.5% of the genes from STS and the remainder from BALB/c. Consequently, the genes participating in the multigenic control of a phenotypic difference between BALB/c and STS become separated into different CcS strains where they can be studied individually. The strain distribution patterns of the proliferative responses to IL-2 and anti-CD3 in the CcS strains are different, showing that different genes are involved. The large differences between individual CcS strains in response to IL-2 or anti-CD3 indicate that both reactions are controlled by a limited number of genes with a relatively large effect. The high proliferative response to IL-2 is a dominant characteristic. It is not caused by a larger major cell subset size, nor by a higher level of IL-2R expression. The response to anti-CD3 is known to be controlled by polymorphism in Fc gamma receptor 2 (Fcgr2) and the CcS strains carrying the low responder Fcgr2 allele indeed responded weakly. However, as these strains do respond to immobilized anti-CD3, while the STS strain does not, and as some CcS strains with the BALB/c allele of Fcgr2 are also low responders, additional gene(s) of the STS strain strongly depress the anti-CD3 response. In a backcross between the high responder and the low responder strains CcS-9 and CcS-11, one of these unknown genes was mapped to the chromosome 10 near D10Mit14. The CcS mouse strains which carry the STS alleles of genes controlling the proliferative response to IL-2 and anti-CD3 allow the future mapping, cloning, and functional analysis of these genes and the study of their biological effects in vivo.

Interleukin-1 and interferon-alpha augment interleukin-2 (IL-2) production by distinct mechanisms at the IL-2 mRNA level.

The production of interleukin-2 (IL-2) by phytohemaglutinin (PHA)-stimulated cells of human leukemia T cell line MOLT-16 can be significantly increased by interleukin-1 (IL-1) or interferon-alpha (IFN-alpha). The enhancing effect of IL-1 and IFN-alpha on IL-2 production was studied at the IL-2 mRNA level. We show that IL-1 enhances considerably and transiently, with the maximum level between 1 and 2 hr after stimulation, the expression of IL-2 mRNA in the PHA-stimulated cells. The level of IL-2 mRNA declined rapidly within 4 to 6 hr after stimulation in both PHA- and PHA plus IL-1-stimulated cell cultures. On the contrary, IFN-alpha does not elevate the level of IL-2 mRNA above the level in PHA-stimulated cultures, but maintains an enhanced level of IL-2 mRNA in the activated cells for more than 6 hr after stimulation. These observations correlate well with the kinetics of IL-2 protein production into the culture media. The results thus suggest that IL-1 and IFN-alpha may exert an enhancing effect on IL-2 production by distinct mechanisms. In addition, none of the five other lymphokines tested (i.e., IL-2, IL-3, IL-4, IL-5, and IL-6) had any significant effect on IL-2 mRNA expression in the activated MOLT-16 cells.

On the role of interleukin-10 in the induction and maintenance of specific transplantation tolerance.

The role of a cytokine synthesis inhibitory factor, interleukin-10 (IL-10), in the induction and maintenance of neonatal transplantation tolerance was studied in mice. We showed that neonatal spleen cells (NSC) significantly inhibited interleukin-2 (IL-2) production by activated T cells from adult mice. Simultaneously we demonstrated a high expression of the IL-10 gene in stimulated spleen cells from newborn mice. However, neutralizing monoclonal antibody (mAb) anti-IL-10 did not abolish the NSC-mediated suppression of IL-2 production. IL-10, therefore, does not appear to be the principal inhibitory molecule responsible for the suppression of IL-2 production. Similarly, specific alloantigen-activated spleen cells from adult tolerant animals were profoundly hyporeactive in IL-2 production. This hyporeactivity was not reversed to a positive reactivity in the presence of mAb anti-IL-10. In addition, anti-IL-10 antibody enhanced proliferation in mixed lymphocyte cultures of cells from both control and tolerant animals, but the antibody did not abrogate specific hyporeactivity of cells from tolerant mice. These results thus showed that newborn animals were nonspecifically and tolerant animals specifically deficient in IL-2 production, but that IL-10 in neither case appeared to be responsible for this IL-2 hyporeactivity.