[Dynamics of T-Cell receptor gene rearrangement and T-lymphocytes migration from thymus during post-radiation regeneration].

Recovery and migration of T-cells from the thymus to the secondary lymphoid organs in mice after sublethal gamma irradiation were investigated by measuring T-cell receptor excision circles (TRECs). The TRECs level practically represents the cellularity of thymus, in particular it correlates with the quantity of T-cells which have rearranged TCR genes and express the receptor complex CD3-TCR. So, TRECs can be considered as one of the markers of these cells. TREC-containing cells form a subset of recent thymic emigrants in the secondary lymphoid organs. After a significant TREC decrease in the lymph nodes within the early phase (4 days) after irradiation, we registered the increase of their number during urgent organ recovery due to T-cell migration from the thymus (the maximum is on the 10th day). The secondary thymic atrophy is accompanied by a weakening migration of the T-cells containing TRECs to lymph nodes. A significant TREC increase in the spleen was registered on the 4th day after irradiation. The rest of the recovery period. (up to 60 days) is characterized by the low TREC level. Thus, determination of TREC level allows obtaining additional information about recovery and migratory processes in lymphoid organs during post-radiation regeneration.

[Analysis of cellular bases of secondary thymic atrophy in irradiated mice by flow cytometry].

Using flow cytometry we looked for a thymocyte subpopulation responsible for the development of thymus urgent recovery and secondary atrophy in sublethally irradiated mice (4 Gy). It was expected that the number of these cells would grow before the urgent recovery peak and would drop during secondary atrophy. It was found out that DN3 thymocytes were the best for these criteria. The DN3 stage of thymocytes development is characterized by the rearrangement of the major portion of T-cell receptor genes. On the basis of this finding we have discussed the possibility of secondary atrophy correction using IL-7.

Neolactoferrin as a stimulator of innate and adaptive immunity.

The effect of the innovative product Neolactoferrin, a natural combination of recombinant human lactoferrin (90%) and goat lactoferrin (10%) isolated from the milk of transgenic goats carrying the full-length human lactoferrin gene, on human immune system cells was studied. Neolactoferrin enhanced the production of IL-1ß. Neolactoferrin saturated with iron ions increased the synthesis of pro-inflammatory cytokine TNFα. It determined the direction of the differentiation of precursor dendrite cells. Under the action of T cells, Neolactoferrin amplified the expression of the transcription factors responsible for the differentiation of Th- and Treg-cells and stimulated the production of both IFNγ and IL-4. The results suggest that Neolactoferrin exhibits an immunotropic activity and hinders the development of immune inflammatory processes. Iron saturation of Neolactoferrin increases its pro-inflammatory activity.

Studying the proliferation of human peripheral blood T lymphocytes in serum-free medium.

We compared the cultivation of human peripheral blood lymphocytes in serum-free medium Hybris-2 and RPMI 1640 medium with 10% fetal bovine serum in the presence of phytohemagglutinin and interleukin-2. The optimal concentration of phytohemagglutinin significantly differed in serum-free and serum-containing media (0.5 and 5 microg/ml, [corrected] respectively). Both mitogens were more potent in stimulating the proliferation of lymphocytes in serum-free medium than in serum-containing medium. Strong proliferation of CD3(+) and CD4(+) T lymphocytes was observed in both media. The dynamics of other markers was similar in serum-free and serum-containing media. However, significant differences were revealed between individual donors. Our results indicate that the developed serum-free medium may be used in lymphocyte cultivation for scientific, diagnostic, and therapeutic purposes.

Oxidized forms of fibrinogen induce expression of cell adhesion molecules by cultured endothelial cells from human blood vessels.

Oxidized forms of fibrinogen similarly to initial non-oxidized fibrinogen induced expression of P-selectin and ICAM-1 cell adhesion molecules in the cultured endothelial cells derived from human umbilical vein. The effect of oxidized fibrinogen on the expression of adhesion molecules was more pronounced. These data attest to more active participation of oxidized forms of fibrinogen into inflammation in the vascular wall, the first stage of atherogenesis.

Thymic epithelial cells induce Fas-independent activation apoptosis of thymocytes.

Co-cultivation of human thymocytes with homologous thymic epithelial cells (TEC) resulted in apoptosis of thymocytes and increase of CD25 expression. TEC supernatant also induced these effects. Fraction of apoptotic cells was enriched by CD69+ cells but not by CD95+ cells. Thymocytes of mice MRL-lpr/lpr bearing mutant form of gene Fas were sensitive to apoptosis induction in co-culture with TEC in the same degree as thymocytes of mice bearing Fas gene of wild type. Apoptosis of murine thymocytes can be induced by co-cultivation with both murine and human TEC.

[In vivo and vitro effects of interferon-alpha 2b on functional activity of T-lymphocytes from patients with rheumatoid arthritis]. / Vliianie alpha2b-interferona in vivo i in vitro na funktsional'nuiu aktivnost' T-limfotsitov bol'nykh revmatoidnym artritom.

AIM: To investigate the effect of recombinant alpha 2b-interferon (r alpha 2b-IFN) on functional capacity of peripheral blood (PB) T cells in rheumatoid arthritis (RA) patients and the relationship between functional characteristics of T lymphocytes and the disease activity. MATERIALS AND METHODS: PB mononuclear cells (PBMC) were separated by Ficoll-Verografine++ gradient centrifugation from 24 healthy donors (HD) and 75 RA patients 19 of which were treated with r alpha 2b-IFN (realdiron, Biofa, Lithuania) in the dosage 1 million IU i.m. each other day for 20 days, 10 injections a course. Cell surface markers (CD3, CD4, CD8) and adhesion molecules (CD18, CD54, CD2) were analyzed using specific monoclonal antibodies (MoAbs) and flow cytometry on the PBMC, freshly isolated and treated for 72 hours with medium alone, PHA, r alpha 2b-IFN and their combination. The proliferative response of PBMC to MoAbs for CD3, PHA and r alpha 2b-IFN were assessed by 3H-thymidine incorporation. The percentage of spontaneous and inducing apoptosis was quantified by flow cytometry using propidium iodide staining. RESULTS: The expression of CD18 was lower on RA PB lymphocytes compared to HD PB lymphocytes (p < 0.05). After stimulation of PBMC in both RA patients and HD with PHA, percentages of CD2+, CD3+, CD4+, CD18+ cells significantly diminished (p < 0.05), whereas the percentages of CD54+ and CD18+ (p < 0.05) cells increased. We have found three types of RA PB lymphocytes response to complex factors in vitro: 1) the presence of the proliferative response to T-mitogens but not to r alpha 2b-IFN (56% of the patients); 2) the presence of the increased proliferative response to T-mitogens and r alpha 2b-IFN (17% of the patients); 3) the absence of the proliferative response to T-mitogens and r alpha 2b-IFN (27% of the patients). PBMC of HD demonstrate only the first type of the response. R2 alpha b-IFN demonstrated own mitogenic effect and increased mitogen-induced proliferation in PBMC cultures with a high proliferative response to T-mitogens. The levels of spontaneous and inducing apoptosis were increased in RA PB lymphocytes compared to HD. After stimulation with PHA, RA PB lymphocytes preferentially underwent apoptosis whereas cells of HD proliferated. High disease activity correlated positively with an increase of a proliferative response to mitogens and apoptosis and a decrease in the percentage of lymphocytes, expressed adhesion molecules. The treatment with r alpha 2b-IFN induces changes in T-cell response to mitogens similarly to those after incubation with r alpha 2b-IFN in vitro before treatment. CONCLUSION: Functional capacity of RA PB lymphocytes relates to the disease activity. Inhibitory or stimulatory effects of r alpha 2b-IFN depend on functional activity of RA lymphocytes. Using the test with alpha 2b-IFN incubation, we may predict changes of apoptosis and proliferation levels caused by different agents in RA lymphocytes after treatment with r alpha 2b-IFN.

[Interferon therapy effects on activation of T-lymphocytes in patients with systemic lupus erythematosus]. / Vliianie terapii interferonom na aktivatsiiu T-limfotsitov bol'nykh sistemnoi krasnoi volchankoi.

AIM: To elucidate the effects of combined therapy with glucocorticosteroids (GCS) and recombinant human interferon alpha or gamma (IFN) on proliferative responses of T-lymphocytes activated by various surface molecules (CD3 and CD2) in patients with SLE. MATERIALS AND METHODS: A 3-month trial entered 3 groups 15 patients each with verified SLE by APA criteria (1982). Patients of group 1, 2 and 3 received IFN-alpha (realdiron, Biofa, Lithuania) in a single dose 3 million IU i.m., IFN-gamma (inflagen, Biofa, Lithuania) in a single dose 3 million IU i.m. and cyclophosphamide in a dose 200 mg i.m. once a week, respectively. T-lymphocyte proliferative response was assessed to stimuli of two types: CD3-dependent (classic activation) and CD2-dependent (alternative activation). The analysis was made by inclusion of 3H-thymidine after 72-hour incubation of peripheral blood mononuclear cells with various stimuli. The response was assessed before the treatment, on the treatment day 20 and after the treatment. The blood from 27 donors was also examined. Flow cytometry estimated the percentage of the cells expressing molecules CD3, CD4, CD8. RESULTS: The effect is found of alpha and gamma INF on functional capacity of T-lymphocytes and on the number of cells expressing surface molecules CD3 and CD4. Realdiron produced two-phase reaction to a proliferative response to mitogenic stimuli by CD3-dependent activation pathway: the initial rise then lowering. CD2-dependent way of T-cell activation is associated with weakening of responses to all combinations of stimuli with participation of autologous red cells. This group of patients to the end of the therapy exhibited a significant decrease in the number of cells expressing CD3 and CD4 (p < 0.05 and p < 0.001, respectively). Inflagen enhanced CD3-dependent activation of T cells and normalized the response to all types of the alternative stimuli. This group demonstrated an increase in the number of cells expressing CD3 and CD4 (p < 0.01 and p < 0.05, respectively). The changes in the number of CD8+ cells in both the groups were statistically insignificant. The controls had T-cell responses reduced by both activation pathways. CONCLUSION: Preparations of both alpha and gamma interferon have a multidirectional influence on functional potential and phenotype of T-lymphocytes of SLE patients.

[The classical and alternative pathways of T-lymphocyte activation in patients with systemic lupus erythematosus]. / Sostoianie klassicheskogo i al'ternativnogo putei aktivatsii T-limfotsitov u bol'nykh sistemnoi krasnoi volchanki.

AIM: To study activation of T-lymphocytes by the CD3 (antigen-dependent) and CD2 (non-antigen-dependent) routes in patients with systemic lupus erythematosus (SLE). MATERIALS AND METHODS: Peripheral blood mononuclears were studied in 66 patients with SLE and 27 donors. Proliferative response to activation by anti-CD3, anti-CD3+ phorbol-12-myristate-13-acetate (PMA), phytohemagglutinin (PHA), and autologous erythrocytes in combinations with PMA and recombinant interleukin-2 (rIL-2) was assessed. RESULTS: T-cell proliferation was at least two times increased under the effect of CD3 in 40.9% patients and in 100% normal subjects. Stimulation with CD3 antibodies in combination with PMA leveled the differences due to boosting of T-cell response in SLE patients. PMA alone caused mononuclear proliferation in 25% patients with SLE but not in normal subjects. Decreased response of T-cells to adhesive stimulus (autologous erythrocytes + PMA) in SLE patients was leveled by rIL-2. CONCLUSION: The proliferative response of T-lymphocytes is decreased upon stimulation with CD3 and CD2 and in some patients increased by PMA in submitogenic doses, added alone or in combination with anti-CD3.

[Changes in the immune system of the victims of the action of the factors in the accident at the Chernobyl Atomic Electric Power Station. Their manifestations, nature and the possible sequelae]. / Izmeneniia v immunnoi sisteme postradavshikh ot deistviia faktorov avarii na ChAES. Proiavleniia, priroda, vozmozhnye posledstviia.

The hypothesis is formulated, which explains genesis of long-lasting disturbances in the immune system of the persons affected by factors of Chernobyl disaster. Immunological alterations which are displayed at the late time after action of radiation in doses 0.5 Gy or lower are not a result of direct damage of the cells of immune system by irradiation. Their development is more probably a result of appearance of some systemic conditions and factors in affected organism--such as hormonal disbalance and especially autoantibodies of different specificities, including those reactive with thymic epithelial cells. Autoantibodies of the last type induce the decrease of thymic hormone secretion which results in functional deficiency of T lymphocytes. This chain of events is similar to those occurring in aging and does not directly causes development of the clinical displays of immunodeficiency. Only irradiation in doses of 4-6 Gy or higher inducing the structural damage of thymic microenvironment can rouse the long-lasting T cell immunodeficiency with the clinical manifestations.

[Immune status of adult population of the Bryansk region living in territory polluted by radionuclides]. / Immunnyi status vzroslogo naseleniia Brianskoi oblasti, prozhivaiushchego na territoriiakh, zagriaznennykh radionuklidami.

Clinical and immunological investigation with immune status evaluation of three groups of adult population of Bryansk Region was performed. The first group included 165 persons living in Vyshkov (settlement of town type in Bryansk Region) contaminated with radionuclides as a result of Chernobyl accident. The second group included 68 persons living in Vyshkov, immunological monitoring of those was performed. The third group consisted of 114 persons living on the "clean" area of Pochep (Bryansk Region). On both areas (contaminated Vyshkov and "clean" Pochep) the large percent of persons (three quarters of all investigated ones) had clinical manifestations of immune deficiency. The immune status of Vyshkov inhabitants was characterized by T-helper/inductor activation. That was expressed in significant increase of CD4+, CD4+/CD8+ in comparison of control group of primary donors and to "clean" Pochep inhabitants and in stable decrease of average values of serum IgG in comparison to control group, IgG and IgM in comparison to Pochep group. Maximum high values of T-helpers under lowest T-suppressor/killer values were observed at clinical symptoms which may be stipulated by radiation factor (loss of hair and teeth, surplus weight, predisposition to bleedings) and in persons working in cattle-breeding.

[The state of classical and alternative complement activation pathways in persons who participated in the cleanup of the aftereffects of the accident at the Chernobyl Atomic Power Plant]. / Sostoianie klassicheskogo i al'ternativnogo putei aktivatsii T-limfotsitov u likvidatorov posledstvii avarii na ChAES.

The levels of T-cell activation through classical and alternative pathways were studied in persons participated in cleaning-up operations at Chernobyl N. P. P. Proliferation response of T-cells on the action of monoclonal antibody anti-CD3 (classical activation) as well as response on phytohaemagglutinin was partially decreased just as response on autologic erythrocytes in combination with phorbol 12-myristate-13 acetate (CD2-dependent alternative activation) was completely suppressed in all affected persons. Addition of interleukin 2 did not restore T-cell responses on both anti-CD3 and alternative stimulation. The different degree of decrease of T-cell responses on anti-CD3 and CD2-dependent alternative stimulation is not a result of respective alterations of cell surface CD3 and CD2 expression.