Abolition of allogeneic inhibition of hematopoietic stem cells by treatment of recipient mice with cyclophosphamide

After transplantation of bone marrow from C57BL/6 mice into lethally irradiated (CBA x C57BL/6)F₁ hybrids, the degree of allogeneic inhibition of the stem cells was 92.5%. Cyclophosphamide, given to the recipients in a dose 200 mg/kg 24h before bone marrow transplantation (4 h after irradiation) reduced the degree of allogeneic inhibition to 24%. Administration of a similar dose of cyclophosphamide did not affect the number of colonies in the spleen of lethally irradiated syngeneic recipients. It is postulated that cyclophosphamide, if injected into lethally irradiated recipients acts on the population of the recipient's radioresistant cells, which are responsible for allogeneic inhibition of the stem cells.Laboratory of Experimental Genetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 447–449, April, 1976.     

Rate of development of immunological memory and characteristics of the secondary immune response in mice of strains with high and low reactivity

Immunological memory for sheep's red blood cells develops in mice of strains CBA and DBA/2 and (CBA×C57BL/6)F₁ hybrids 24 h after injection of a small dose of the antigen, but 48 h after injection in C57BL/6 mice. The level of the secondary immune response in CBA, C57BL/6 and F₁ hybrids is significantly higher than in DBA/2 mice. Maximal production of antibody-forming cells in the spleen of the CBA mice is observed after two injections of small doses of the antigen. By contrast to this, to obtain a marked immune response in the case of adoptive transfer of spleen cells of C57BL/6 mice a second injection of a large dose of antigen is required.Laboratory of Immunogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. H. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 454–457, October, 1977.     

Effect of cortisone-resistant thymocytes on endogenous colony formation in inbred mice

Endogenous colonies were counted in the spleen of sublethally irradiated (CBAxC57BL/6)F₁ hybrid mice after injection of thymocytes and lymph node cells treated with hydrocortisone and in intact CBA mice. Cortisone-resistance thymoctyes did not inhibit endogenous colony formation, whereas lymph node cells had a marked suppressive effect on endogenous colonies. In individual recipients the number of colonies in the spleen after injection of cortisone-resistant thymocytes was twice the number found in control irradiated hybrids.Department of Microbiology and Department of Biology, Smolensk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 7, pp. 66–68, July, 1977.     

Changes in the number of antibody-forming and stem cells in the spleen of unilaterally nephrectomized mice

A suspension of spleen cells from intact and unilaterally nephrectomized mice, obtained in the latter case 19–21 h after the operation, was injected into lethally irradiated (CBA×C57BL/6) F₁ mice 24 h after irradiation. On the 8th day after injection of the cells the number of colony-forming and plaque-forming cells in the spleen of the irradiated recipients was determined. To determine the number of plaque-forming cells, a mixture of spleen cells and sheep's red cells was injected into the irradiated recipients. The number of colonies in the recipients' spleen 19–21 h after the operation either was unchanged or was significantly reduced. Stimulation of the production of antibody-forming cells was observed at these same times, and it coincided in time with the period of manifestation of the ability of the splenic lymphoid cells of the unilaterally nephrectomized mice to induce proliferation in the kidney of the intact recipients.Laboratory of Experimental Genetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR. Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR, N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 9, pp. 69–72, September, 1974.     

Suppressor activity of spleen cells in drug-induced immunologic tolerance

Tolerance to sheep's red blood cells (SRBC) was induced in (CBA×C57BL/6)F₁ mice by a single intraperitoneal injection of 6×10⁹ SRBC followed by injection of 100–200 mg/kg cyclophosphamide 44–46 h later. Spleen cells of tolerant mice, obtained at various times (12–26 days) after induction of tolerance, when injected into intact syngeneic recipients, did not depress their immune response to SRBC. Unlike intact mice, tolerant mice were unable to produce suppressor cells after a single immunization with SRBC. Only if three additional injections of large doses (6×10⁹) of SRBC were given to the tolerant mice did their spleen cells acquire the ability to inhibit the immune response on injection into normal mice. It is postulated that the absence of suppressor cells on induction of immunologic tolerance by means of cyclophosphamide is due to clonal elimination. Suppressor cells may arise in tolerant animals under the influence of intensive antigenic stimulation, leading to deepening of the state of tolerance as a result of additional injections of SRBC.Laboratory of Immunogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 558–560, November, 1978.     

A study of the lymph-node type of graft versus host reaction in mice

A local form of the graph versus host reaction (GVHR) was induced in adult (CBA×C57BL)F₁ hybrid mice by subcutaneous injection of semiallogeneic spleen, thymus, or bone marrow cells from CBA mice into the right hind footpad. The criteria of activity of the GVHR were an increase in the number of blast forms in the region of popliteal lymph node and in its weight 7 days after transplantation of cells. After transplantation of 5×10⁶ and 20×10⁶ spleen cells the absolute weight of the regional lymph node was increased by 3–5 times and was significantly higher than in the control (injection of living syngeneic or fragmented semiallogeneic cells from the same source). By contrast with the control, in the experimental animals the effect clearly depended directly on the dose of transplanted cells. Enlargement of the lymph nodes was accompanied by the regular appearance of blast forms in them. Thymus and bone marrow cells had a much weaker action than spleen cells.Department of General Pathology, Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR Siberian Division, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 338–339, March, 1976.     

Changes in H-alloantigen-recognition function of lymphocytes after hydrocortisone administration in mice

The ability of spleen, thymus, and bone-marrow cells of intact (control) and hydrocortisone-treated (experiment) CBA mice to induce a lymph node graft versus host reaction (GVHR) in (CBA×C57BL)F₁ hybrids was compared. After injection of hydrocortisone into the donors in a dose of 2.5 mg per mouse their spleen cells induced a more active GVHR, as shown by an increase in the lymph node indices and in the percentage of immunoblasts in the regional (popliteal) lymh node compared with the control. After transfer of thymus cells of hydrocortisone-treated donors the number of immunoblasts was higher than, but the weight of the lymph node was almost the same as in the control. Conversely, after injection of bone marrow cells from hydrocortisone-treated donors, the lymph node enlarged whereas the percentage of immunoblasts did not increase above the control. Consequently, when the increase in the hydrocortisone level is exogenous in nature, the cell populations of the spleen and thymus contain a higher proportion of T lymphocytes, which respond by proliferation to contact with H alloantigens.Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 458–459, October, 1977.     

Effect of regeneration of the spleen and bone marrow on number of hematopoietic colonies in the mouse spleen

Two thirds of the spleen (group 1) or the bone marrow from the right tibia (group 2) was removed from sexually mature male CBA mice. On the eighth day after lethal irradiation and injection of 1·10⁶ nucleated cells from the intact spleen the number of hematopoietic splenic colonies was counted. A significant increase in the number of colonies was observed in the animals of both experimental groups compared with the control intact mice. the authors suggest that this increase may have been caused both by the local effect of the regenerating splenic stroma and by a certain stimulating factor secreted by the regenerating hematopoietic tissue.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. Department of Histology, Biological Faculty, Moscow State University. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1375–1376, November, 1976.     

Immunocompetence of lymphocytes from pregnant mice studied in graft versus host reaction

The ability of lymphocytes taken during the second trimester from C57BL/6 mice mated with CBA males to induce the graft versus host reaction in (CBAxC57BL/6)F₁ hybrids was weaker than that of cells both of virgin donors and of mice pregnant after syngeneic mating. This was reflected in lengthening of the life span of the experimental recipients and weakening of inhibition of endogenous colony formation in the spleen of sublethally irradiated hybrids. This ability was restored at the end of pregnancy and in some experiments it actually exceeded the control.Department of Microbiology, Smolensk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 310–312, March, 1977.     

Development of the cellular immune response to tuberculin in mice of different genotypes

Inbred CBA and C57BL mice and (CBA×C57BL)F₁ hybrids were immunized intraperitoneally with Freund's complete adjuvant and the production of macrophagal migration inhibiting factor (MIF) by lymphocytes in different situations was investigated. Lymphocytes were activated to produce MIF in a certain order: cells of the peritoneal exudate first, then lymph node cells and, finally, spleen cells. Maximal MIF production by lymphocytes of the peritoneal exudate was obtained in C57BL mice, and it occurred earlier (on the 3rd day after immunization). Increased spontaneous migration of macrophages also was observed after immunization and it was more marked in the CBA mice.Department of Immunology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. V. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 972–974, August, 1976.     

Effect of stimulation and inhibition of erythropoiesis on antibody production and migration of B cells from the bone marrow and spleen in mice

The effect of stimulation and inhibition of erythropoiesis on the production of antibody-forming cells (AFC) in the spleen and on the migration of B cells from the bone marrow into the spleen was studied in CBA mice. Stimulation of erythropoiesis was shown to increase the number of AFC in the spleen and migration of B cells from the bone marrow into the spleen sharply 1 and 4 days after blood loss. Inhibition of erythropoiesis led to a very small increase in the number of AFC in the spleen 4 and 7 days after transfusion of syngeneic red cells and inhibited migration of B cells from the bone marrow into the spleen. The possible mechanisms of the effect of stimulation and inhibition of erythropoiesis on antibody formation are discussed.Laboratory of Regulation of Immunopoiesis, Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 303–305, March, 1977.     

Interaction between T and B lymphocytes and their migration in the immune response during methylcholanthrene-induced carcinogenesis

Methylcholanthrene (MC) was injected intramuscularly in a dose of 0.3 mg into (CBA×C57BL)F₁ mice and the ability of their T and B lymphocytes to cooperate during the immune response to injection of sheep's red blood cells and also migration of these cells from the thymus and bone marrow into the spleen were investigated. The results showed that the immunodepressant action of MC is connected with inhibition of processes of migration and cooperation of T and B lymphocytes in the immune response. It is concluded that the immunosuppression developing during carcinogenesis is complex in character and is realized at different stages of immunogenesis.Institute of Biophysics, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. D. Gorizontov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 464–466, October, 1977.     

Kinetics of hematopoietic stem cells in the bone marrow of hepatectomized mice

Two thirds of the liver was removed from (CBA×C57BL/6j)F₁ female mice. On the 5th day after the operation a significant increase was observed in the number of endogenous colonies in the spleen of the partially hepatectomized animals. This increase was not connected with a change in the number of stem cells in the bone marrow, for partial hepatectomy at different times after the operation did not affect the number of colony-forming units in the bone marrow.Laboratory of Virology, Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 218–219, February, 1978.     

Stimulation of humoral immunity to surface antigens of leukemic cells by interferon-containing serum

C57BL/6 mice were immunized by a single injection of L-1210 leukemia cells and (CBA×C57BL/6)F₁ mice were immunized by a single injection of leukemia L-1210 and P-388 leukemia cells. For 8 days (including the day of immunization) the animals received daily intraperitoneal injections of 0.4 ml of allogeneic or syngeneic interferon-containing serum, whereas control animals received the same dose of normal serum from intact mice (the interferon-containing serum was obtained from (CBA×C57BL/6)F₁ mice 24 h after intraperitoneal injection of 2 mg tilorone hydorchloride). Some samples of interferon-containing serum were dialyzed for 48 h against physiological saline. The serum interferon titer was 512–1500 units/ml. On the 9th–10th day after immunization the mouse sera were put through the microcytotoxic test against leukemia cells. Definite stimulation of the cytotoxic activity of sera of mice receiving the interferoncontaining serum was discovered. The syngeneic interferon-containing serum produced a stronger immunostimulant effect than the allogeneic serum.Laboratory of Immunology of Leukemia, Central Institute of Hematology and Blood Transfusion, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 358–360, March, 1976.     

Action of a polysaccharide from Salmonella typhi on hematopoietic stem cells

The dynamics of the number of colony-forming units (CFUs) in the spleen and bone marrow of unirradiated F₁(CBA×C57BL) mice was studied after intraperitoneal injection of polysaccharide (PC) fromSalmonella typhi. The method of exogenous colony formation was used. After a single injection of PC the number of CFUs in the bone marrow was increased by 2–2.5 times and in the spleen by 3 times. Repeated (6–9 times) injections of PC were no more effective than a single injection. PC evidently acts as an inducer which, by inducing proliferation of hematopoietic stem cells, maintains this process automatically for a certain period of time.Laboratory of Radiation Immunology, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR G. V. Vygodchikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 79, No. 3, pp. 66–68, March, 1975.     

Heterogeneous hemoglobin system of anemic rats

The fractional composition of hemoglobin from the peripheral blood, spleen, and bone marrow of intact and anemic rats was studied by electrophoresis in polyacrylamide gel. Anemia was produced by injecting phenylhydrazine hydrochloride into the animals. The basic principles of formation of the heterogenous hemoglobin system, depending on the source from which it was obtained and on the state of the animals, were established. The possible causes of the observed reorganization of the fractional composition of hemoglobin and its biological significance are discussed.Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukrainian SSR, Kiev. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1328–1330, November, 1976.     

Effect of various factors on the formation of immunological memory

Experiments on mice in which sheep's red cells were used as antigen showed that the height of the secondary immune response of spleen cells in situ or in adoptive transfer is inversely proportional to the dose of red cells used for primary immunization. Cyclophosphamide, injected into the animals simultaneously with the antigen, stimulates the immune response of the mice to the second injection of red cells, but this effect is observed only when comparatively large doses of antigen are used for priming. The mechanisms of this phenomenon are discussed.Laboratory of Immunogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 336–339, September, 1977.     

Hybrid resistance of bone marrow stroma to precursor cells

The focus of hematopoiesis arising after transplantation of a fragment of bone marrow from a C57BL mouse beneath the capsule of the kidney of a syngeneic mouse contains more hematopoietic cells than if transplanted into a semisyngeneic (CBA x C57BL)F₁ recipient. Experiments with repopulation of the graft, when depopulated by irradiation, by injected hematopoietic cells of the same genotype as the graft (C57BL) showed that these differences are due to the smaller size of the hemotopoietic microenvironment in the focus formed in the hybrid than in the syngeneic system. Hybrid resistance is thus manifested not only against hematopoietic cells, but also against stromal precursors transferring the hematopoietic microenvironment.Laboratory of Cultivation and Transplantation of Bone Marrow, Central Institute of Hematology and Blood Transfusion, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 339–342, March, 1977.     

The parental resistance phenomenon and its genetic regulation

Lymphocytes of (CBA×M523)F₁ or (A×M523)F₁ mice, if transplanted into CBA or A recipients irradiated in a dose of 1000 rad, react to test antigens (sheep's red cells,Salmonella typhi Vi-antigen) by the formation of only 1/100–1/1000 of the number of antibody-forming cells formed by syngeneic recipients. An intermediate result was observed after transplantation of the same cells into irradiated M523 recipients. Conversely, lymphocytes of (A×CBA)F₁, (CBA×C57BL/6)F₁, or (A×A.CA)F₁ mice gave an equal immune response in syngeneic recipients and in CBA or A recipients. The ability of M523 lymphocytes or their hybrids to give an immune response to sheep's red cells did not differ from the immuno-reactivity of lymphocytes of other lines either in situ or in a syngeneic adoptive system. Hematopoietic stem cells from (CBA×M523)F₁ mice formed only 40–50% of the number of colonies in the CBA spleen as in the spleen of syngeneic recipients. It is concluded that the M523 mutation interferes with the proliferation and differentiation of hematopoietic cells and lymphocytes in nonsyngeneic irradiated recipients.N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 3, pp. 247–250, March, 1979.     

Syngeneity as a factor in cooperation between T- and B-lymphocytes

Effectiveness of cooperation between (CBA x C57BL/6)F₁ thymocytes and CBA bone-marrow cells in the immune response to sheep's red cells was compared with syngeneic combinations of the same cells in culturein vivo. The selectiveness of cooperation between T- and B-lymphocytes of different origin also was investigated in incomplete (CBA x C57BL/6)F₁CBA chimeras obtained with the aid of cyclophosphamide, in which the donors were primed with sheep's red cells and the recipients were either intact or were tolerant to that antigen. F₁ T-cells were shown to cooperate with CBA B-cells 10–50 times less effectively than with syngeneic B-cells. It is postulated that the similar antigenic structure of the cell membrane of T- and B-lymphocytes, acting in conjunction with their physical contact, increases the effectiveness of action of the T-mediator on the B-cellLaboratory of Immunological Tolerance, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 325–327, March, 1976.