Thymic deletion of V beta 11+, V beta 5+ T cells in H-2E negative, HLA-DQ beta+ single transgenic mice

DQw6b transgenic mice have been generated by microinjecting a linearized cosmid clone containing 34-kb DQb genomic DNA, isolated from HLA-homozygous B cell line AKIBA (DR2, Dw12, DQw6), into embryos of (CBA x B10.M)F2 or (SWR x SJL)F2. Among 85 mice screened, eight mice were transgene-positive. The transgene in seven of eight founders was germline-transmitted. FACS analysis and immunohistochemical studies with DQ beta-specific mAb demonstrated that DQ beta molecules in association with mouse A alpha f molecules are expressed on peripheral mononuclear cells, spleen cells, and in thymic medulla. More interestingly, V beta 11-, V beta 5.1-, and V beta 5.2-bearing T cells, but not V beta 8.2-bearing T cells, were clonally deleted in the H-2E-negative but DQ beta+ progeny of two selected founders (260-23 and 258-10). The deletion was found to take place intrathymically during the transition stage from immature to mature thymocyte development. We postulate that although human DQ genes are more homologous to mouse H-2A genes, A alpha f/DQ beta hybrid molecules may possess the same self-peptide- (or superantigen)-presenting epitope as E alpha/E beta molecules critical for deletion of V beta 11-, V beta 5.1-, and V beta 5.2-bearing T cells in thymus. Our results also confirm the previous findings that accessory molecules on thymocytes such as CD4 may be involved in thymic selection, and further suggest that an interaction of mousE CD4 and mouse A alpha chain is required for the clonal deletion.

Thymic deletion of V beta 11+, V beta 5+ T cells in H-2E negative, HLA-DQ beta+ single transgenic mice

DQw6b transgenic mice have been generated by microinjecting a linearized cosmid clone containing 34-kb DQb genomic DNA, isolated from HLA-homozygous B cell line AKIBA (DR2, Dw12, DQw6), into embryos of (CBA x B10.M)F2 or (SWR x SJL)F2. Among 85 mice screened, eight mice were transgene-positive. The transgene in seven of eight founders was germline-transmitted. FACS analysis and immunohistochemical studies with DQ beta-specific mAb demonstrated that DQ beta molecules in association with mouse A alpha f molecules are expressed on peripheral mononuclear cells, spleen cells, and in thymic medulla. More interestingly, V beta 11-, V beta 5.1-, and V beta 5.2-bearing T cells, but not V beta 8.2-bearing T cells, were clonally deleted in the H-2E-negative but DQ beta+ progeny of two selected founders (260-23 and 258-10). The deletion was found to take place intrathymically during the transition stage from immature to mature thymocyte development. We postulate that although human DQ genes are more homologous to mouse H-2A genes, A alpha f/DQ beta hybrid molecules may possess the same self-peptide- (or superantigen)-presenting epitope as E alpha/E beta molecules critical for deletion of V beta 11-, V beta 5.1-, and V beta 5.2-bearing T cells in thymus. Our results also confirm the previous findings that accessory molecules on thymocytes such as CD4 may be involved in thymic selection, and further suggest that an interaction of mousE CD4 and mouse A alpha chain is required for the clonal deletion.

[Relation between left ventricular mass and function with plasma catecholamines in progeny of hypertensive parents]

To study whether left ventricular mass and function are related to the activity of the sympathetic nerves in progeny of hypertensive parents, LV parameters by echocardiography and plasma catecholamines by HPLC were used in 33 normotensive sons with two hypertensive parents (SHT) and 33 normotensive sons without family history of hypertension (SNT). The results showed that interventricular septum and left ventricular posterior wall thickness, left ventricular mass were significantly greater in SHT group than in the SNT group. No significant difference was found in plasma catecholamines between SNT group and SHT group. But, positive correlation between left ventricular mass and plasma norepinephrine was observed both in SHT group and SNT group. The regression coefficient in SNT was greater than that in SHT. The left ventricular mass and plasma epinephrine were positively correlated in SHT group. These results suggest that cardiac involvement may precede blood pressure elevation in SHT group and the changes of cardiac morphology might show that myocardium is more sensitive to the activity of sympathetic nerves system in SHT than in SNT.

Formation of 2-methyltryptophan in the biosynthesis of thiostrepton: isolation of S-adenosylmethionine:tryptophan 2-methyltransferase

L-2-Methyltryptophan was found to be an intermediate in the biosynthesis of the antibiotic thiostrepton. It was isolated from growing cultures and resting cells of Streptomyces laurentii in trapping experiments after the application of labeled L-methionine or L-tryptophan. Its formation from L-tryptophan and S-adenosylmethionine was studied in a cell-free extract of S. laurentii. Although several attempts to purify the soluble methyltransferase by standard methods failed, some of its characteristics could be determined in the crude extract. The enzyme has a sharp pH optimum at pH 7.8. The apparent Km value for S-adenosylmethionine is 120 microM and the Ki value for S-adenosylhomocysteine is 480 microM. The enzyme is not stereoselective with respect to D- or L-tryptophan, but the D-isomer is converted at a slower rate than the L-isomer. Indolepyruvic acid is also methylated, while indole is not a substrate. The methyl group is transferred with retention of its configuration, contrary to most other methyltransferase reactions.

[Pharmacologic studies on qiongjiang wine]

In this article, preliminary pharmacologic studies of Qiongjiang wine are reported a comparison of this wine with Guilingji wine is made. The results show that Qiongjiang wine has the action of roborant and sex hormones. It can improve the phagocytic function of macrophage in the abdominal cavity of mice. No toxic response has been found in acute toxicity test.

[Treatment selection for stage I breast cancer--report of 412 cases]

From 1958 to 1982, 412 Stage I breast cancer patients treated by simple operation, operation plus radiotherapy and/or chemotherapy are reported. Of them, 312 were treated by radical mastectomy (R), 43 by simple mastectomy (S), 31 by modified radical mastectomy (M), 20 by tumorectomy (T) and 6 by extended radical mastectomy (E). The results showed that M and T with radiotherapy and/or chemotherapy were similar to R in terms of survival and recurrence rates. There were no differences between R, S, M, E groups and combined treatment group in recurrence rate, but there was a significant difference between T group and combined treatment group (P less than 0.01). Recurrence rate of patients with positive axillary lymph nodes was similar to that of patients with negative nodes, because 91.5% of the former patients received combined treatment, but only 54.3% of the latter patients did (P less than 0.01). Six cases in T group recurred and 4 (67%) of them were retreated by salvage surgery. Three cases survived for 15 years, giving a better result than radical mastectomy. It is indicated that modified radical mastectomy and tumorectomy plus combined treatment are advisable for Stage I breast cancer. Prospective randomized clinical trials for assessment of different treatment modalities are needed.

In vitro proliferation of murine spleen cells: genetic control of proliferative responses induced by phorbol ester and calcium ionophore A23187

Proliferative responses of normal (not immunized intentionally) spleen cells from inbred strains of mice to co-stimulation with phorbol ester (PMA) and calcium ionophore A23187 were studied. Striking differences in the magnitude of the responses of spleen cells and splenic T cells from various strains were observed. It appeared that these differences reflected mainly differences in the inducibility of the expression of the gene for the alpha chain of the IL2 receptor (IL2R) by phorbol ester. Formal genetic analysis suggested that the differences in response to phorbol ester and calcium ionophore are controlled by two independent genes with the alleles controlling good response being dominant. The differences in the inducibility of the IL2R gene seemed to be controlled by alleles of a single gene. At least one of the putative genes may be a regulatory element affecting the gene for the alpha chain of IL 2R. The results may have a practical significance for devising more efficient procedure(s) to generate LAK cells used for tumor immunotherapy.

In vitro proliferation of murine spleen cells: I. Strain variation of response to medium from cultures of EL-4 cells

Proliferative responses of murine lymphoid cells were elicited in vitro with supernatant fluid from cultures of EL-4 thymoma cells stimulated with phorbol ester. It was demonstrated that such responses depend on IL-2 contained in the supernatant fluid, but reflect co-stimulation with IL-2 and phorbol ester. Striking differences in the magnitude of proliferative responses of spleen, splenic T lymphocytes, thymus and bone marrow cells from various strains were observed. Three classes of responders could be identified. The differences in responsiveness, at least in part, reflected differences in the frequency of responsive cells and were genetically controlled by codominant alleles of two independent somatic genes.

In vitro proliferation of murine spleen cells: inhibition by monoclonal antibodies to L3T4 and Lyt-2 T cell markers or intracellular cyclic adenosine monophosphate

Proliferation of normal (not immunized intentionally) murine spleen cells was elicited with concanavalin A, supernatant fluid from cultures of EL-4 cells, human recombinant interleukin 2 (IL-2), or a mixture of phorbol ester and calcium ionophore A23187. IL-2-induced proliferation was inhibited by membrane-permeable dibutyryl cyclic adenosine monophosphate (cAMP) or by the adenylate cyclase activator forskolin. Consistent with these observations was the finding that stimulation with IL-2 decreased and forskolin increased the intracellular content of cAMP. IL-2-induced proliferation, as well as that induced by concanavalin A or phorbol-ionophore mixture, was inhibited by monoclonal antibodies specific for L3T4 or Lyt-2 cell surface markers. This inhibition was observed even when antibodies were added several hours after exposure of cells to IL-2. Notably, antibodies did not alter the intracellular content of cAMP. Thus, the experimental data failed to establish a functional linkage between the inhibitory effect of antibodies and the regulatory effect of the adenylate cyclase system. However, our results provide a rational basis for the postulation that antibodies, upon binding to their corresponding ligands, generate a negative signal that interferes with IL-2-induced proliferation. Therefore, L3T4 and Lyt-2 molecules appear to play an important role in the regulation of lymphocyte proliferation.

In vitro proliferation of murine spleen cells. Strain variation of proliferative responses induced by recombinant IL-2

Proliferative responses of normal (not immunized intentionally) spleen cells from inbred mouse strains to human recombinant interleukin 2 (L-2) were studied. It was shown that inbred strains vary in their responses to IL-2. The differences were observed for various doses of IL-2 and at various times after stimulation. Experimental data suggested that the strain differences in the magnitude of proliferative responses may result from an interplay of several interrelated factors such as differences in the frequency of the IL-2-responsive cells, differences in inducibility of the expression of the gene for the alpha-chain of the IL-2R, and genetic control of the responses. The latter was found to be exerted by two independent genes with the dominant alleles determining good responses to IL-2. The magnitude of the responses to IL-2 correlated with the magnitude of responses to concanavalin A, but seemed to have no effect on the interferon production or on the primary response to sheep red blood cells. The described phenomenon may have a practical significance in studies aimed at improving tumor immunotherapy with lymphokine-activated killer cells.