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The receptor structures of activating and inhibiting types of innate immunity central cells (macrophages and natural killer cells) participating in supporting genetic homeostasis and providing organism protection from extracellular and intracellular microbes and other alien cells, have been considered. The molecular physiological formation mechanisms of intracellular signal ways providing macrophage activation under interaction influence of Toll-like phagocyte receptors with one of its ligands: lipopolysaccharide that is the main component of gram-negative bacterium membrane have been analysed.

The hemopoietic stem cells (HSC), obtained from the mouse bone marrow and transferred into lethally irradiated syngeneic mice, do not form colonies of hemopoietic cells in the spleen of recipients. The colony formation has been observed after transplantation of HSC together with bone marrow B-lymphocytes or precursors of T-lymphocytes (PTL), and has been mediated through soluble products of nonimmunoglobulin nature produced by B-cells. In distinction from bone marrow B-cells, the interaction of splenic B-lymphocytes with the HSC fraction does not initiate this process, but suppresses it in the presence of bone marrow PTL. The interaction of B-lymphocytes activated by LPS (in vitro) or sheep erythrocytes (in vivo) with HSC or with a mixture of HSC and PTL resulted in the formation of splenic colonies. However, the induction of colony formation has been observed only in the presence of mature T-lymphocytes (phenotype Thy-1, Sc-1), revealed as an admixture to HSC, and has been abolished after their removing in the process of fractionation of bone marrow and receiving the purified HSC fraction. It requires some membranous interaction of regulatory cells.

Peripheral blood leukocytes of intact dogs, when transplanted to sublethally irradiated mice, have been found to suppress endogenous colony formation. The inactivation effect in hemopoietic stem cells of mice is enhanced with an increase in the number of effector cells in the graft. Radiation exposure results in failure of the effector function of leukocytic cells at the peak of acute radiation sickness. Nine months after irradiation, the inactivating capacity of dog leukocytes is restored and exceeds that of the control. Administered to dogs 9 months after irradiation, proteus vaccine stimulated the effector function of leukocytes at days 7 and 28 and suppressed it at days 14 and 62 post-administration.

The influence of cytokine complex and its fractions, produced by peripheral blood mononuclear cells on the healing of rabbit corneal wounds has been investigated. The cytokine complex affected on the early stage of wound healing, and was more effective than fractions of this complex. The delay of regeneration and as a result--formation of more thin scar have been observed.

Peripheral blood and bone marrow morphology, blood and bone marrow lymphocyte subpopulation composition were studied in two children with cyclic neutropenia, using flow cytofluorometry, monoclonal antibodies, colony-forming capacity of granulocytic macrophagal precursors in semi-fluid agar. The studies were conducted in varying periods of the neutropenic cycle. Differences were revealed in immunohematologic parameters and clinical course of neutropenia in the two patients. The analysis of the literature data and the authors' own observations of the patients with cyclic neutropenia permitted a suggestion on high heterogeneity of pathogenetic mechanisms of this disease.

The influence of B-lymphocytes from various sources on splenic colony formation was studied in the syngeneic system. B-lymphocytes were obtained by panning with IgG-fraction of rabbit anti-mouse Ig, absorbed on Petri dishes. In addition, adherent cells, Thy-1+ and SC-1+ were eliminated from the fraction of Ig(+)-cells. SC-1- and SC-1+ fractions, containing, respectively, stem cells and T-lymphocyte precursors, were obtained by panning with IgG-fraction of rabbit anti-SC-1 serum. SC-1- cells transferred to irradiated syngeneic mice did not induce colony formation in the spleen. Introduction of SC-1- and SC-1+ cells induced formation of colonies. A similar helper effect occurred when SC-1(-)-cells were introduced with bone marrow or lymph node B-cells, but not with splenic B-cells. Splenic, but not bone marrow and lymph node B-cells inhibited colony formation by combination of SC-1- and SC-1+ cells. All effects of Ig+ cells were abolished by treatment of cells with rabbit anti-MBLA serum. Thus, B-cells of various origin can either enhance or inhibit colony formation. The enhancing of inhibitory effect after B (MBLA+)-cells elimination from suspension of bone marrow and lymph node (but not spleen) Ig(+)-cells resulted from the activity of B-contrasuppressors.

The role of T-lymphocytes, bearing antigens Lyt-1, Lyt-2 and L3T4, in regulation of the functional activity of blood-forming precursor cells of syngen and non-syngen origin was investigated. The treatment of cells of murine lymphatic nidi with monoclonal antibodies to the above antigens and with the complement did not abolish the capacity of T-lymphocytes of controlling proliferation and differentiation of syngen and allogen blood-forming precursor cells. The subpopulation characteristics of lymphocytes interacting with the stem cells is discussed.

The study of Kemantan on functionally alternative humoral immunity regulator cells: T-helpers and antigen-specific T-suppressors, including their induction, accumulation and functioning, was studied. Kemantan in doses of 0.2-200 mg/kg, introduced to the donors of T-helpers 2 days before they were taken, stimulated their activity 1.5- to 2-fold (with p less than 0.05). Kemantan had no influence on the functional activity of T-suppressors, as well as on their induction and accumulation.

The in vivo study of the influence of Kemantan on the growth of endogenous colonies in the spleen of sublethally (6 Gy) irradiated (CBA x C57BL/6J) F1 mice (mitostatic action) and on the capacity of transplanted lymphocytes of CBA mice for suppressing their multiplication (lymphotoxic action) was carried out. Besides the capacity of Kemantan for affecting the induction, formation and functioning of B-suppressors of antibody formation was studied. As revealed in this study, Kemantan in doses of 0.2-200 mg/kg did not produce a mitostatic and lymphotoxic effect and had no influence on the realization of the suppressing action of mature B-suppressors. In doses of 20 and 200 mr/kg Kemantan, injected to donors at the phase of the induction and accumulation of B-suppressors, abolished their formation.

We have detected and characterized a subpopulation of immunoregulatory cells, i.e., B-helpers capable to enhance the activity of Td-lymphocytes and controlling differentiation of syngeneic hemopoietic stem cells in mouse spleen and bone marrow. B-helpers found in the spleen and lymphatic nodes are resistant to radiation (at a dose of 6 Gr) but are impaired when irradiated at 9 Gr. Manifestation of the helper activity does not require either DNA or RNA synthesis but depends on protein synthesis and is mediated by soluble transmitter substances. Initial activation of B-helpers by lipopolysaccharide or alloantigens does not affect their helper functions. In the absence of T-lymphocytes B-cells do not affect differentiation of hemopoietic stem cells; interaction of B-helpers with differentiating Td-lymphocytes is not genetically restricted. Using preparative electrophoresis, we could isolate fractions of Td-lymphocytes which require or do not require B-helper cells in order to induce change in differentiation of hemopoietic stem cells from mainly erythroid to preferentially granulocyte pathway.

Subpopulational composition of peripheral blood and bone marrow lymphocytes was studied in 17 children with different forms of immunodeficiency, combined with hematological shifts (agammaglobulinemia--6, mucocutaneous candidiasis--2, selective IgG-deficiency--2, hyper-IgM syndrome--3, cephalo-oculocutaneous telangiectasia (COCT)--2, general, variable immunodeficiency--2 patients; neutropenia was observed in all the patients, lymphopenia--in 13, anemia-in 6 patients. Surface markers were assayed by flow cytofluorometry with monoclonal antibodies OKT3, OKT4, OKT8, OKB7, produced by "Ortho diagnostics". Changes characteristic of certain forms of primary immunodeficiency have been revealed in the subpopulational composition of peripheral blood and bone marrow lymphocytes: decreased helper potential in patients with general variable immunodeficiency, T-lymphocyte deficiency in patients with COCT increased number of phenotype T3 cells and decreased amount of B-cell in agammaglobulinemia patients. Significant heterogeneity has been noted in the parameters of hemogram, myelogram and in the subpopulational composition of peripheral blood and bone marrow lymphocytes in each nosologic form, the group of patients with hyper-IgM syndrome has proved to be most heterogeneic. It has been suggested that the changes in the subpopulational composition of bone marrow lymphocytes may be responsible for primary immunodeficiency and disorders in hemopoiesis.

Changes in the number of spleen exo-colonies and post-radiation repopulation of hematopoietic organs were studied in recipients upon injection of bone marrow treated with anti-brain serum (ABS) with and without thymocytes on days 9-14. It was shown that on days 9-11 colony formation in mice injected bone marrow treated with ABS was much lower than the control level. However, by day 14 the number of colonies increased drastically as compared to the control. Thymocyte supplementation normalized colony formation at any time of observation. Similar pattern is noted in post-radiation repopulation of spleen and bone marrow of mice injected bone marrow pretreated with ABS with or without thymocytes. It is assumed that ABS inactivates bone marrow cells participating in the regulation of CFUs proliferation.

Expression of the inactivation effect of the stem colony-forming marrow cells of male mice CBA, C57B1/6, (CBA.C57B1/6)F1 and (C57B1/6.CBA)F1 by syngeneic lymphocytes of lymphatic nodes of females in conditions of transplantation of cell mixtures into lethally irradiated recipients was studied. The maximum inactivation effect of stem cells (86.3%) is determined in mice F1 with differences of H-Y antigen, the minimum effect (2.4%)--in mice CBA, an intermediate effect (54%) being registered in mice C57B1/6. Sensibility of target cells to the inactivation influence of lymphocytes distinguished by weak transplantation H-Y antigen depended on the maternal effect and direction of reaction. The inactivation effect was maximal in the combination CBA----C57B1/6 and C57B1/6----C57B1/6, as compared with the combination CBA----CBA and C57B1/6----CBA. Possible mechanisms by which the killer action of syngeneic lymphocytes on the antigen H-Y of target cells is developed differently, are under discussion.

Bone marrow stem cells of the parent genotype (CBA) produce mainly erythroid colonies in the spleen of lethally irradiated recipients (CBA-C57Bl)F1. T d-lymphocytes change this differentiation pattern from the mainly erythroid to the mainly myeloid pathway. The irradiation with 100 R does not abolish this effect. The lymphocytes irradiated in vitro with 200 R or more, and incubated with Mitomycin C or Cycloheximide lost the ability to change the differentiation pattern of the transplanted cells. T d-lymphocytes are radiosensitive cells that need DNA and protein synthesis for realizing their function.

The time during which transplated lymphocytes block proliferation and differentiation of non-syngeic stem cells has been determined by retrasplantation of immuno-competent cells from one lethally irradiated recipient to another one. It was established that process of inactivation of CFU by allogeneic lymphocytes proceeds itwo stages. At the first stage, the colonization of recipient's tissues takes place. The colonization of tissues and processes of early recognition are completed during the first hours after transplantation of cell mixtures. At the second stage, the processes of redistribution of injected cells occur and a complete inactivation of stem cells take place. These events are completed in bone marrow and spleen 4-5 days after transplantation of cells mixture, possibly with the participation of lymphocytes sensibilized with the target-cells.

Diiodobenzo-tepa (DIB) was given orally to CBA mice in a dose of 25 mg/kg for 3 successive days. The number of nucleus-containing cells decreased 3.9 fold in the thymus and 1.4 fold in the bone marrow. In experiments on transplantation of lymphoid cells to intact or lethally irradiated (CBA X C57BL/6J)F1 mice treated with DIB this substance did not influence the helper activity of T lymphocytes but inhibited the activity or B and T lymphocytes, inducing "graft-versus-host" and T cell-suppressor functions.

Antisera to membrane antigens of B lumphocytes eliminated the capacity of lymphocytes to inactivate allogenous stem cells by 60%; however, lymphocytes from the lymph nodes of B mice possessed no inactivating capacity. T-lymphocytes were the main criteria inactivating allogenous stem cells. Cooperating with T-lymphocytes, B-lymphocytes probably contributed to inactivation of precursor cells realized by T-lymphocytes. However, the presence of B-lymphocytes in the killer cells population was not a determinant, since T-lymphocytes were capable of inactivating allogenous stem cells without any participation of B-lymphocytes.

The clinical course and some immunohematologic parameters of the blood and bone marrow were investigated in chronic neutropenia children with a high break of granulocyte maturation. Heterogeneity of etiopathogenetic mechanisms of the disease has been recorded in this group of children.

Bone marrow cells together with allogeneic cortisone-resistant thymocytes or the lymph node cells of intact mice treated with antilymphocytic T or O-antisera were transplanted to the lethally irradiated mice. The antisera eliminated the capacity of T lymphocytes to inactivate allogeneic stem cells. Cortisone-resistant thymocytes displayed a strong inactivating action. The principal role in the processes of inactivation of genetically foreign stem cells was played by T lymphocytes. B lymphocytes possessed no properties of killer cells. The presence of B lymphocytes in the population of killer cells apparently failed to serve as a determinant one for the development of inactivation processes.

A study was made of the influence of T-cell mitogens (Con A and PHA) on the colony formation and differentiation of hemopoietic stem cells from normal and thymectomized mice, as well as of the relationship between the colony formation and the dose of injected thymocytes. The incubation of bone marrow cells with Con A and PHA was shown to inhibit the growth of spleen colonies. This inhibition is reduced by thymocytes within the dose intervals of 0.25-2.0 X 10(7) cells/mouse. Administration of these agents serially has led to the potentiation of inhibition effect and to the inability of thymocytes to reverse it. Con A and PHA exert no effect on the differentiation of stem cells. Incubation of the bone marrow cells from thymectomized mice with Con A is much less effective in the depression of colony formation, if compared with the treatment by intact bone marrow preparations. A reversed picture was observed using antiserum to mouse brain (RAMBS). It is proposed that regulation of stem cells is governed by different subpopulations of thymocytes.

After separation of the bone marrow or the spleen suspension on the discontinuous albumin gradient cell fractions were obtained in which the activity of the DNA-dependent DNA polymerase, aspartate carbamoyl transferase, as well as the rate of the 14C-thymidine incorporation in the DNA was 2 to 3 times higher than in the original suspension. The most actively DNA-synthesizing cells were concentrated in the 5th-6th fractions when the osmolarity of 35% BSA was 370 mOsm, or in the 2nd-3rd fractions when the osmolarity of 35% BSA was 380 mOsm.

The influence of the T-system of immunity on the processes of the proliferation and differentiation of hemopoietic precursor cells outside the organs of the hemopoietic and lymphoid systems has been studied. Thymocytes have been found to regulate the formation of hemopoietic foci in the peritoneal cavity. The effects of the stimulation and suppression of colony formation, as well as the degree of their manifestation, depend on the initial level of the colonies. The thymectomy of the recipients or donors of hemopoietic cells leads to the increase of colony formation. Syngeneic thymocytes abolish the effect of thymectomy.

A mixture of lymph node cells from CBA mice and spleen cells from C57Bl/6J mice stimulated by the cheep erythrocytes fro the first or second time was transplanted in the lethally irradiated mice (CBA X C57Bl/6j)Fl. The interaction of allogenic cells during the secondary immune response was accompanied by the complete inactivation of antibody producents. Under the ratio of interacting cell elements 1 : 1-1 : 2, 93-96% of precursor cells and 98% of antibody forming cells were inactivated. Under the ratio 1 : 5, the index of inactivation of precursor cells fell down to 35%. During the primary response, under the ratio 1 : 1, only 20-48% of precursor cells and 68% of antibody forming cells were inactivated. Under the ratio 1 : 2, no inactivation of precursor cells was observed and, under the ratio 1 : 10, the antibody formation was stimulated. Following the delayed by 1-3 days transplantation of CBA lymphocytes, the cooperative effect was registered with respect to the spleen cells from C57Bl/6J mice stimulated by the erythrocytes for the first time. The interaction of allogenic cells resulted in the 3-4-fold increase in the number of antibody forming cells.

The lymph node cells were treated with monoclonal anti-Lyt-3 antibodies (anti-Lyt-3) and complement. Their interaction with colony-forming units (CFU) of bone marrow was studied. Anti-Lyt-3 did not affect the activity of T-lymphocytes, which changed the pattern of syngenic CFU differentiation in spleen of irradiated mice. On the contrary, the activity of T-lymphocytes, which inactivated proliferation and differentiation of non-syngenic CFU in spleen, was decreased. In the peritoneal cavity of irradiated mice antibodies did not affect the activity of T-lymphocytes which suppressed the colony-formation of non-syngenic stem cells and switched off the activity of T-lymphocytes that stimulated syngenic CFU colony-formation. The subpopulation characteristics of regulatory and effector T-cells has been analysed.

CFU-S differentiation and regeneration kinetics in the spleen and femur was studied after treatment of bone marrow cells with RAMB serum. The effect of thymocytes on the rate of CFU-S regeneration was also investigated. It was found that CFU-S regeneration in the spleen was similar in RAMBS-treated and intact cell populations on days 4-14 after transplantation. On the contrary, the rate of CFU-S regeneration in the femur was slower in RAMBS-treated than in intact bone marrow cells. However, the growth rate in the femur could be restored to the normal level by the administration of freshly isolated syngeneic thymocytes to mice pre-injected with RAMBS-treated CFU-S population. The treatment of bone marrow suspension with RAMB serum did not affect the differentiation of spleen colonies. It is suggested that RAMBS eliminates cell population regulating CFU-S proliferation, without affecting its differentiation.

A mixed transplantation of bone marrow cells, and lymph nodes or thymic cells of mice CBA strain into lethally irradiated hybrid recipients (CBAXC57B1)F1 is accompanied with changes in the differentiation pattern from a mainly erythroid to a mainly granuloid way. Thymectomy of either donor of bone marrow cells or recipients, or both, destroys the stem cell differentiation in the direction of granulopoieseis. Intact syngeneic lymphocytes normalize differentiation of the stem cells, but in the presence of tissue antigens these provide for the stem cell differentiation mainly in the direction of granulopoiesis. The differentiation of stem haemopoietic cells is accomplished under the thymic and lymphocyte control. T-differentiating lymphocytes (Td) are the lymphocytes controlling the stem cell differentiation.

The expression of allogenic inhibition was studied when transplanting 10(5) cells of bone marrow of C57BL mice to the lethally irradiated recipients (CBA X C57BL) F1 of different age (2 to 11 months). In the control experiments the bone marrow cells at the same dose were introduced to the lethally irradiated syngenic (C57BL) mice. The most pronounced inhibition of the parental stem cells proliferation was registered in 2 months old recipients F1 (4.7 times), it was somewhat weakened in 3 months old and animal in 4--11 months old recipients (1.1 to 1.8 times). The thymectomy of adult recipients F1 did not eliminate the expression of allogenic inhibition.

The influence of myelopeptides on differentiation of bone marrow haemopoietic precursors cells in thymectomized and normal mice has been studied in vivo. The introduction of myelopeptides decreased the number of erythroid (E) colonies and increased that of granulocytic ones (G). This results in the decrease of initially raised E/G ratio in thymectomized mice (from 4.3) down to 1.3). Myelopeptides exerted no influence on haemopoietic precursors in normal mice (E/G-2.0).

The number of colonies formed in the peritoneal cavity (on the artificial underlayer made of peritoneal cells) and in the spleen of lethally irradiated recipients, (CBA X X C57BL) F1 mice, after the intraperitoneal injection of marrow cells depends on the cell donor's genotype: syngeneic cells and cells from mice of the parent strain CBA form fewer colonies in the peritoneal cavity than in the spleen, while cells from C57BL mice produce the reverse distribution of colonies between the peritoneal cavity and the spleen. Allogenic lymphocytes, when transplanted simultaneously with hematopoietic cells, suppress colony formation in the peritoneal cavity from day 2 of cultivation and eliminate the already developed foci of hematopoiesis by day 5.

No colonies were found in the spleen at "early" times (7-8 days) after irradiation of mice with doses of 8-9 Gy, while at "later" times (after 15 days) a confluent growth of the colonies was observed. The endogenous splenic foci of haemopoiesis of the "late" type were characterized by the preferable growth of granulocytic colonies.

Transplantation of the bone marrow cells with allogeneic T-lymphocytes to the irradiated hosts was accompanied by inactivation of the stem elements of the graft. The lymph node cells of T-mice (those deprived of B cells) were more active than the spleen cells of these mice. The stem cells inactivation was weakly expressed or absent in case of a combined acti-n of T-cells from the lymph nodes and the spleen.

The role of different T lymphocyte subpopulations in the process of allogeneic haemopoietic stem cell inactivation has been studied. The T lymphocyte subpopulations were fractionated in vivo using the homing properties (to the spleen and lymph nodes) plus sensitivity for ALS in vivo (recirculation properties), for thymectomy, for anti-Thy 1 serum in vitro and some others. The results obtained indicate that not only the killer lymphocytes, that provide stem cell inactivation, but also the suppressor cells, that provide inhibition of inactivation, take part in the reaction for allogeneic stem cells. Killer and suppressor cells differ alternatively in some physiological properties and may be separated for further studying.

A mixture of the bone marrow cells and lymphocytes of the lymph nodes of C57BL mice was injected intravenously to A X C57BL mice irradiated in a dose of 850 R. It appeared that under the effect of syngenous lymphocytes of C57BL mice the colony-forming cells (CFC) of the bone marrow of the F1 hybrid mice proliferated as if they were in the syngenous organisms. Along with the restoration of the number of CFC capable of forming colonies in a genetically foreign organism these cells, under the effect of lymphocytes, altered the direction of differentiation which was characterized by increase in the number of granulocytic colonies. This process was accompanied by the development of the blast transformation reaction and hyperplasia of the lymphoid tissue of the recipient spleen.