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[Mechanism of the formation of micronuclei in PHA-stimulated lymphocytes from human peripheral blood].

The micronuclei of PHA-stimulated human lymphocytes were assayed by comparison of electron microscopy and light microscopy data. The length of the cell cycle was checked by the flow cytofluorimetry method. Both the variability of the apoptosis stages and the increase in (G2+M) period in gamma-irradiated cultures were found. It is concluded that at least part of the micronuclei results from the cell nucleus "partition" during the apoptosis type cell death.

Cell Cycle↗

Comparison of in vitro and in vivo mitogenic and polyclonal antibody and autoantibody responses to peptidoglycan, LPS, protein A, PWM, PHA and Con A in normal and autoimmune mice.

We have compared the in vitro and in vivo mitogenic and polyclonal antibody (IgM-, IgG-, IgA- and IgM anti-SRBC-secreting PFC) and autoantibody (IgM anti-ssDNA-, anti-bromelin-treated [HB]- and anti-intact mouse RBC-secreting PFC) responses to peptidoglycan (PG), LPS, protein A, PWM, PHA and Con A in young (4-7 weeks) and old (7-8 months) normal (BALB/c, CBA/H, C57BL/6) and autoimmune (NZB, NZB X NZW F1, BXSB, MRL/1; old BXSB and MRL/1 were 4-5 months) mice. Our results demonstrated that: lymphocytes from young and old autoimmune mice (except old BXSB) could be further polyclonally activated in vitro by PG or LPS as well as or better than lymphocytes from young and old normal mice; lymphocytes from young or old autoimmune mice were less polyclonally activated in vitro by protein A or PWM, respectively, than lymphocytes from young or old normal mice; PG and LPS were equally effective polyclonal activators in vitro; in vivo, LPS was a stronger stimulant than PG; in vivo, LPS could induce polyclonal activation in both young and old normal and autoimmune mice, whereas, PG could only induce polyclonal activation in vivo in young and old normal mice, but did not induce further activation in young and old autoimmune mice; only some tests (anti-ssDNA and IgG PFC in vivo, and IgA and anti-HB MRBC PFC in vitro) revealed higher responses in autoimmune than in normal mice, and these higher responses were seen more often in vivo than in vitro; both autoimmune and normal mice had a high frequency of autoantibody (especially anti-ssDNA) secreting cells in polyclonal activation in vitro, whereas a high frequency of these cells in vivo was only found in autoimmune mice; in most cases in vitro, polyclonal activators did not change the frequency of autoantibody and heteroantibody secreting cells, but in vivo, both PG and LPS increased the frequency of anti-ssDNA antibody secreting cells in normal, but not in autoimmune, mice; LPS increased the in vivo, but not in vitro, frequency of cells secreting anti-HB MRBC antibodies in some strains of mice; old mice had lower mitogenic responsiveness than young mice in both autoimmune and normal strains; autoimmune mice had similar, higher or lower mitogenic responses than normal mice, depending on the strain and the age, but in most cases consistent for both B and T cell mitogens; and there was no correlation between the patterns of increased or decreased mitogenic and polyclonal antibody responses in normal and autoimmune mice.4+.

Age Factors↗

Mechanism of accessory cell requirement in inducing IL 2 responsiveness by human T4 lymphocytes that generate colonies under PHA stimulation.

PHA-driven monoclonal colony formation by low concentrations of resting T4 lymphocytes in agar culture requires the presence of interleukin 2 (IL 2) and accessory cells. Using recombinant IL 2 and anti-Tac monoclonal antibody as a probe for the IL 2 receptor, we demonstrate that the requirement of accessory cells (here an irradiated B cell line) in inducing IL 2 responsiveness relies on their enhancing effect in functional IL 2 receptor expression by the T colony progenitors. Furthermore, it is shown that cell to cell interaction between accessory cells and colony progenitors results in IL 2 response, i.e., colony formation, when the IL 2 receptor density reaches a critical threshold. The asynchronism in IL 2 responsiveness expression by the T colony progenitors upon activation and the short-lived T cell-accessory cell interaction, due to accessory cell death, determine the 10% colony efficiency of the culture system. In addition, we demonstrate that the accessory function in IL 2 receptor and IL 2 responsiveness expression by the T colony progenitors can be supported by irradiated T lymphocytes as well as B cells. The absence of lineage restriction of the signal delivered by accessory cells, and the requirement of physical interaction between T colony progenitors and accessory cells, emphasize the necessity of cross-linking the activation-signal receptors in inducing IL 2 responsiveness by resting T4 cells.

Antibodies, Monoclonal↗

Immunoregulatory leucocyte subset typing and PHA response in relation to the nutritional state in cancer patients with gastrointestinal neoplasia.

Cancer patients are frequently immunodepressed and this could be related to undernutrition, particularly in gastrointestinal (GI) neoplasia. We therefore looked for correlations between different leucocyte subsets' (T11+, T4+, T8+, B1+, and Mo2+) cells in the peripheral blood of these patients and their nutritional state. Significant alterations were found in absolute number/ml of T11+, T4+, B1+, and Mo2+ cells. Malnourished cancer patients were more affected than those appearing well-nourished, exhibiting a decrease of 50% in the number of T11+, T4+, and B1+ cells as compared with healthy controls. The phytohemagglutinin A (PHA) stimulation index (SI) was also significantly decreased in the malnourished group. Linear regression analysis between SI and these leucocyte subsets revealed that only the T4+ cells offered a significant correlation (r = 0.6169 p less than 0.01). These results suggest that the absolute number/ml of T4+ cells reflects the nutritional state of patients bearing GI tumors.

Aged↗

[Effect of PHA on lymphocyte respiratory activity in mice].

A study of the intensity of oxygen consumption by mice lymphocytes at different stages of cultivation with PHA showed a pronounced increase of the respiratory activity beginning from the 14th hour. Maximum values of oxygen consumption by stimulated cells were observed at the 16th and 30th hours of cultivation (before the beginning of blastogenesis and before the maximum uptake of H3-thymidine, respectively.

Animals↗

The role of shed Fc receptor in the regulation of lymphocyte response to phytohaemagglutinin (PHA).

Supernatants from 18-hr cultures of human peripheral blood polymorphonuclear cells (PMN) and adherent cells (AC) inhibited the binding of erythrocyte-antibody complexes (EA) by PMN. The inhibitory activity was lost upon absorption on IgG and Fc, but not on the F(ab')2 fragment of IgG. IgG-binding material (shed Fc receptor--FcR) was reutilized by PMN and AC which had lost their own FcR in vitro. Reutilization was independent of the type of cells from which FcR originated. The FcR-containing material eluted from IgG-coated Sepharose column inhibited PHA-induced lymphoproliferation, probably via prior interaction with monocytes. These results suggest that shed FcR may be freely exchanged between different types of human leucocytes and play a role in the suppression of mitogen-induced T-cell responses.

Cell Adhesion↗

[Correlation between DNA repair synthesis and number of cells with micronuclei during gamma-irradiation of human peripheral blood lymphocytes stimulated and not stimulated with PHA].

The method of colony chromatography on BND-cellulose was used to study DNA repair synthesis (RS) after gamma-irradiation in PHA-stimulated and nonstimulated lymphocytes. The injury to lymphocytes at the cellular level was estimated by the micronuclear test. The comparison of the data on the rate of RS and the number of cells with micronuclei showed that RS inhibition, in the case of the postirradiation treatment of cells with arabinoside cytosine, leads to a decrease in viability of lymphocyte populations, the G0 cells being primarily damaged.

Chromosome Aberrations↗

The effect of C-reactive protein on the PHA-induced proliferation of human peripheral blood lymphocytes.

The effect of CRP purified from ascites fluid originated from cancer patients on human peripheral blood lymphocytes was investigated. CRP was purified using 4-step procedure including absorption on Sepharose 4B, phosphocholine-Sepharose, DE-52 ion exchange chromatography and gel filtration on Sephacryl S-200. CRP was able either to inhibit or to enhance PHA-induced lymphocyte proliferation in vitro. The effects of added CRP depended on the time of its addition, dose of CRP and lymphocyte donor.

C-Reactive Protein↗

The effect of in vitro irradiation on PHA-mediated cytotoxicity and lymphocytes with receptors for the Fc part of Ig.

In vitro irradiation of purified human lymphocytes reduced PHA-mediated cytotoxicity (MICC) against chicken erythrocytes in a dose-dependent fashion. Lymphocytes with receptors for IgG present in both unfractionated and T-cell enriched cell preparations were depleted after X-ray exposure. T-cells with IgM-receptors, however, appeared to be more resistant. Different lymphocyte subpopulations seem to cooperate in MICC, and shifts of their proportions may be one explanation of the reduction of MICC after X-ray exposure.

Animals↗

In vivo effect of DDS on phytohemagglutinin (PHA)-induced lymphocyte transformation cultures in normal healthy volunteers.

Depression in PHA-induced lymphocyte transformation in peripheral blood has been observed in 15 healthy volunteers after administration of DDS (100 mg/day) for seven days. In vitro culture of lymphocytes obtained from these volunteers in DDS-free normal AB serum has not altered the blast cell numbers. Lymphocytes of these volunteers have been found to contain a significant amount of DDS, ranging from 0.42 to 3.2 micrograms per 10.6 lymphocytes.

Dapsone↗

Role of L-alanine in the response of human lymphocytes to PHA and Con A.

The response of umbilical cord blood lymphocytes (UCBL) to PHA and Con A is strongly dependent upon the presence of dialyzable plasma components. The impaired response of human cells in the presence of dialyzed human plasma was restored by calf thymus extract. In the present experiments we have further purified calf thymus extract by means of paper electrophoresis and chromatography on thin-layer cellulose plates. We reached the conclusion that the active material in this model is a single amino acid, alanine. When the different isomeric forms of alanine were tested, we found that L-alanine is the only biologically active material. In addition, we have observed here that the allogeneic response of UCBL is also dependent upon the presence of dialyzable plasma components. This impaired allogeneic response of UCBL in the presence of DHP was restored by addition of L-alanine. The present findings suggest that, under in vitro conditions, for human cells to respond to mitogenic or allogeneic stimulation L-alanine is essential.

Alanine↗

The cells involved in the immune response of fish: II. PHA-induced clonal proliferation of carp lymphocytes in soft agar culture.

Lymphocytes from peripheral blood of carp proliferate in a clonal culture in soft agar, in the presence of phytohemagglutinin, generating several morphologically distinct types of colonies. Cells from colonies developing on the surface of the agar (surface colonies) and cells from colonies developing within the agar (agar colonies) were studied. Several differences were found between cells from the two types of colonies with respect to morphology, ultrastructure and the distribution of cytoplasmic determinants antigenically related to serum immunoglobulin. Colonies were quantitated as a function of the number of cells seeded, in primary cultures of peripheral blood leukocytes and in secondary (replated) cultures of isolated surface colony cells. The numbers of surface colonies and agar colonies in the two systems were comparable. Preferential formation of surface over agar colonies was noted, and there was an initial concentration of cells (individual for each fish) which resulted in optimal colony growth. This method was found to be suitable for isolating highly homogeneous subpopulations of PHA-responsive lymphocytes, which could subsequently be further expanded in liquid culture. A requirement for an exogenously produced growth factor (possibly similar to mammalian Interleukin 2) in the maintenance of long-term clonal cultures is suggested.

Agar↗

Lack of T cell antigen expression on hairy cells of B cell origin after in vitro exposure to PHA.

The malignant monoclonal population in hairy cell leukemia (HCL) has been variously ascribed to be of myeloid, B, or even T cell origin. Recent data have been interpreted as suggesting that hairy cells (HC) may concomitantly or serially express both B and T surface determinants, a phenomenon which, if verified, would be unique among the lymphoproliferative malignancies. Data described here, however, demonstrate that (1) at least the majority of HCL are phenotypically of B cell derivation, and (2) the initial B cell phenotype is retained and solely expressed on cultured as well as phytohemagglutinin (PHA) activated monoclonal malignant HC.

Adult↗

Certain characteristics of human lymphocyte migration inhibitory factors (LyMIF) and the effect of ampicillin on their appearance in unstimulated and PHA-stimulated cultures.

Supernatants of human blood mononuclear cells stimulated with PHA, contained factors inhibitory for in vitro migration of human lymphocytes and granulocytes. After ultrafiltration of supernatants through Amicon PM-10 some stimulatory activity appeared in the bottom fraction. Sephadex G-100 gel filtration chromatography of supernatants showed three zones of lymphocyte migration inhibitory activity: In the range of molecules of m.w. 35 000-90 000, heat-stable; Factors of m.w. from several to from ten to twenty thousand daltons, heat unstable; Low molecular weight substances, resistant to heat. The possible relationship of these factors to lymphotoxins, soluble lymphocyte T receptors for SRBC, lymphocyte chemotactic factor and prostaglandins is discussed. Ampicillin in doses of 10, 20 and 50 micrograms/ml potentiated both the development of lymphocyte migration inhibitory factors and the production of factors with an opposing effect (stimulating lymphocyte migration).

Ampicillin↗

Immunological studies in leprosy--II: Study of lymphoblast transformation to PHA in different types of leprosy patients.

Ninety cases of different types of leprosy were studied for lymphoblast transformation response using PHA-M. The difference of percentage was statistically analysed and found to be highly significant when total leprosy cases were compared with control cases and with different types of leprosy cases (P = less than .005), except control and TT where it was significant only (P = less than .05). The difference between TT and other types was also calculated and has been observed to be highly significant (P = less than .005). There was gradual decrease in lymphoblast transformation percentage from tuberculoid pole to lepromatous pole.

Female↗

PHA-induced human T cell colony formation: enhancing effect of large granular lymphocytes.

The capacity of phytohemagglutinin (PHA)-stimulated human T cells to develop into colonies in agar has been evaluated in the presence or absence of a variety of peripheral blood mononuclear cell subsets. A subpopulation of non-T, non-B cells with receptors for the Fc portion of IgG (i.e. third population cells or TPC) was found to enhance considerably the T cell colony forming capacity. Since TPC have been previously shown to be highly enriched for large granular lymphocytes (LGL, i.e. cells with cytoplasmic azurophilic granules and acid hydrolases), LGL were purified on Percoll density gradients and tested for their T cell colony enhancing capacity. It was shown that LGL were indeed the cells capable of enhancing the T cell colony formation.

Cell Separation↗

The effects of NSAID on monosodium-urate (MSU) skin test and on other in vivo skin tests (SK/SD; PHA).

The authors have pointed out a monosodium-urate (MSU) skin test in vivo, showing a practical usefulness in short-time evaluation of effects of non-steroidal antiphlogistic drugs (NSAID) in man; the isotopic curves, in the area of the skin test, reproduce those obtained in endogenous articular phlogosis. THe authors have studied, at the same time, the actions of NSAID on other skin tests (SK-SD; PHA) which reproduce, in earlier phases of cutaneous reaction, some aspects (erythema, thermographic values, isotopic curves) of 'immediators' phlogosis. The results show that the MSU skin test is more useful in studying the effects of NSAID for the feature of other skin test reactions are affected by many factors.

Anti-Inflammatory Agents↗