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PubMed1979

Studies of the nonspecific cellular immune response in patients with urinary bladder carcinoma. I. PHA-induced lymphocyte transformation.

The nonspecific cellular immune response, as measured by phytohemagglutinin (PHA)-induced blastoid transformation of peripheral lymphocytes in autologous serum, was evaluated in 119 patients with bladder carcinoma and in 21 control subjects. Blastoid transformation was determined by quantifying 3H-thymidine incorporation (counts per minute). The rate of blastogenesis of lymphocytes was shown as the stimulation index which was calculated by dividing the number of counts per minute with PHA by that without PHA. The stimulation index of the control subjects was 29.9 +/- 6.6 (+/- SD); that of the experimental group was 13.3 +/- 7 (significantly lower reactivity). There was a converse correlation between the stimulation index and the grade and stage of tumor. In some cases the change in cellular immunity was compared before and after surgery.

Adult↗
PubMed1979

Formation of thromboxane B2 and hydroxyarachidonic acids in purified human lymphocytes in the presence and absence of PHA.

The metabolism of exogenous and endogenous [14C] arachidonc acid was studied in purified human peripheral blood lymphocytes carefully freed of contaminating platelets. Formation of products co-migrating in a number of different solvent systems with 5-hydroxyarachidonic acid (5-HETE), thromboxane B2 (TB2), prostaglandins and probably 12-hydroxyarachidonic acid (12-HETE) was demonstrated. In cells prelabeled with [14C] arachidonic acid, phytohemagglutinin (PHA) produced substantial (3.5- to 12-fold) increases in 5-HETE, 12-HETE, and TB2 radiolabeling. The metabolism of exogenous [14C] arachidonic acid was much less affected by PHA. Since PHA releases cell-bound arachidonic acid, it appears that the response involving endogenous label is due to increased availability of free arachidonic acid rather than induction of arachidonic acid-metabolizing enzymes. Various inhibitors of arachidonic acid metabolism exerted similar effects in lymphocytes to those described previously in other tissues providing a possible basis for interpreting their inhibitory effects on mitogenesis, described in the preceding paper.

Arachidonic Acids↗
PubMed1979

Differences in [3H]-thymidine uptake of lymph node cells stimulated by Con A and PHA in H-2 congenic mouse strains.

The genetic control of the lymphocyte responsiveness to Con A and PHA-P has been studied by using inbred, H-2 congenic mouse strains. Segregation studies were carried out on F1 and backcross mice of a high and a low responder strain. According to the results, there is a strong correlation between the responsiveness of lymph node cells to mitogens and H-2 haplotypes in different H-2 congenic strains of mice and in different backcross generations. High responsiveness to PHA-P is associated with H-2b, while low responsiveness with H-2a or H-2k haplotypes, but the correlation is the inverse in response to Con A, in the parental strains and backcross mice as well. The magnitude of the responses to both Con A and PHA-P was found to be intermediate in F1 heterozygotes of a low and high responder parental strain. The effect of other non H-2 genes on the responsiveness to these mitogens has also been demonstrated.

Animals↗
PubMed1977

The effect of PHA-activated MN-cell supernatants on polymorphonuclear leucocyte function.

The effect of PHA-activated mononuclear-cell (MN) supernatants on various polymorphonuclear-leucocyte (PMN) functions were assessed. Treatment of PMN with PHA-activated MN-cell supernatants resulted in greater electrophoretic mobility, indicating an increase in the negative surface charge. PMN directional motility was inhibited in the presence of active supernatants but was not affected by a pulse exposure of the PMN to these supernatants. Neither control nor active supernatants were chemotactic for PMN, but treatment of these cells with active supernatants produced an increase in their phagocytic activity, their ability to reduce NBT and in their glucose oxidation through the hexosemonophosphate shunt. Bactericidal capacity of these PMN was unaltered. Specific loss of leucocyte inhibitory factor (LIF) activity from supernatants of PHA-activated MN cells followed their absorption with PMN cells but not with human MN cells or guinea-pig peritoneal exudate cells. Furthermore, acquired inhibition of migration of the absorbing PMN was observed.

Blood Bactericidal Activity↗
PubMedDate not supplied

Stimulation of progressor and regressor chicken leukocytes with Con A, PHA-P, and Rous sarcoma tumor antigens.

Progressor (Pr) and regressor (R) chickens from the University of Arkansas lines were used as leukocyte donors. Peripheral blood leukocytes were stimulated with two mitogens, concanavalin A (Con A) and phytohemagglutinin-P (PHA-P). Both Pr and R leukocytes displayed the same Con A-stimulated dose dependency on blastogenesis. The regressor leukocytes were stimulated more than the progressor leukocytes at high concentrations of PHA-P. There did not appear to be any correlation between the response of individual chickens to mitogens and their ability to regress a Rous sarcoma. We concluded that the R-Rs-1 gene, which controls the animal's response to Rous sarcoma, and the Con A and PHA-P response genes are probably located at different loci in the chicken genome. Mitogen-induced blastogenesis does not appear to be a useful index to predict regression response in the chicken. Under our experimental conditions, regressor leukocytes showed a sensitization to sarcoma antigens, but the progressor leukocytes did not. The data suggest that the R-Rs-1 gene does not confer a generally enhanced immune status to the chicken but acts as an Ir response gene to augment the immune response to specific antigens.

Animals↗
PubMed1984

Immunoregulatory T cells in measles. The relationship between reduced lymphocyte proliferative response to PHA and increased proportion of circulating suppressor-cytotoxic T cells.

Viral infections are often associated with immunodeficiency states. Although T lymphocytes have been thought to suppress the host's immune response, the precise cellular basis for this phenomenon remains unclear. Therefore, we characterized peripheral blood mononuclear cells from 9 measles virus-infected children by means of monoclonal antibodies directed against surface antigens expressed on human T lymphocytes and T-cell subsets. In addition, the measles lymphocyte blast transformation response to the T-cell mitogen phytohaemagglutinin (PHA) was evaluated as an index of specific T-cell immunocompetence. During the course of measles, there was a slight reduction in the proportion of total circulating T cells, with a relative decrease in helper-inducer and a parallel increase in suppressor-cytotoxic T lymphocytes. The PHA lymphocyte blastogenic response was found to be defective in children with measles and, interestingly, there was a significant negative correlation between the reduced PHA blast transformation value and the increased proportion of suppressor-cytotoxic cells. The biological implications of these finding with respect to the underlying immunopathology of the measles virus infection are discussed.

Antibodies, Monoclonal↗
PubMed1984

Effect of dichloromethylene diphosphonate (Cl2-MDP) on bone resorption induced by PHA-stimulated human mononuclear cells in organ culture.

Human mononuclear cells stimulated by PHA caused resorption of fetal rat bones in tissue culture. Non-adherent cells alone failed to produce substantial bone resorbing activity. The mixed culture of adherent and non-adherent cells (1:40) produced significant bone mineral resorption in vitro. The bone resorption induced by human mononuclear cells stimulated by PHA required the presence of living bone tissue in culture. The bone resorbing effect caused by PHA-stimulated cells was blocked by dichloromethylene diphosphonate at 10(-5) M concentration, but mononuclear cells preincubated in diphosphonate containing media were capable to resorb fetal rat bone in tissue culture.

Animals↗
PubMed1983

T-cell differentiation in the rabbit. II. Con A and PHA response of thymus, spleen and lymph node cells and of thymus subpopulations; influence of dexamethasone treatment.

Mitogen-induced proliferation of rabbit lymphocytes from the thymus (Thy), spleen (Spl) and lymph node (LN) was measured by [3H]thymidine incorporation. The various cell suspensions taken from normal animals showed wide differences in their response to Con A and PHA. Cell suspensions taken from steroid-treated animals did not show differences in response. The disappearance of these differences in mitogen reactivity after steroid treatment is caused by a decreased Con A response of LN cells and an increased Con A and PHA response of Thy cells. The results suggest the existence of a steroid-sensitive (Ss). Con A-responsive cell population in LN cells. The mitogen response of untreated and steroid-resistant (SR) Thy cells was further investigated in cell suspensions separated on density gradients and in cell suspensions enriched in, or depleted of cells bearing receptors for Fc (T gamma and T non-gamma, respectively). It is concluded that Ss thymocytes of high density are mitogen non-reactive, and that Ss cells of low and medium density consist of subpopulations of cells reactive to Con A and/or to PHA. Sr thymocytes still displayed heterogeneity in buoyant density and mitogen responsiveness. Heavy cells and T gamma cells (10% of the Sr cells were T gamma) showed a lowered mitogen response. The results are discussed in relation to data describing the localization of the cell types which differ in mitogen reactivity. The results support the idea of two differentiation pathways, one for Ss and the other for Sr thymocytes.

Animals↗
PubMed1984

PHA-induced LRP enhancement of normal PBL by Rollin.

The purpose of the study was to determine whether the "RSTL-SAS" derived Rollin has retained the precursor activity after its purifying procedure. The blastogenic response of macrocultures (650) to PHA and Rollin was assessed by microscopy. Data have clearly shown that Rollin, like RSTL-SAS, may significatively enhance the PHA-induced LPR of PBL from healthy humans. Such enhancement depends of the Rollin dose added to the culture and kinetics of the target cells sensitive to it. However, Rollin seems to provide more efficiency and safety than RSTL-SAS. The positive capabilities of the "RSTL-SAS" were largely overpassed by the purified Rollin. A positive response (probably via T-cell precursor repertoire), was seen in 82% of the 151 individuals studied. The joint PHA plus Rollin LPR mean values got up to 119% and 159% of the "IIC.PHA" base-line for the "BR100" model (one full-dose) and the "BR.MCR" in the subset with six doses of Rollin/Control, respectively. Moreover, the negative side of the RSTL dual-effect became insignificant for Rollin and antibodies against Rollin or other detrimental side-effects which could restrict its therapeutic use as it has occurred with other BRM, have not been detected after the reiterative i. v. and/or i. m. administration of large Rollin doses to adult rabbits.

Adult↗
PubMed1983

Modulation of PHA-induced T colony formation by phorbol myristic acetate.

PMA (10 ng/ml), induced a four-fold increase in PHA-induced T colony formation by peripheral blood lymphocytes (PBL). At lower (0.1-1 ng/ml) and higher concentrations (100-1,000 ng/ml), PMA had an inhibitory effect. The potent co-mitogen effect observed at 10 ng/ml PMA was associated with a strong increase in T colony promoting activity (TCPA) released by PHA stimulated PBL cultured in the presence of PMA (10 ng/ml). PMA at all concentrations exerted an inhibitory effect on T colony formation when PBL were cultured in the presence of PHA and an optimal concentration of exogenous TCPA. PMA was also capable of assuming the essential role played by monocytes in T colony formation. Thus, PMA can fulfil both co-mitogen and monocyte like roles in T colony formation. These activities closely resemble those previously described for interleukin 2 (IL2) production.

Clone Cells↗
PubMed1983

Decreased TCGF activity in the culture medium of PHA stimulated peripheral mononuclear cells from patients with metastatic cancer.

Activities of T cell growth factor (TCGF) of conditioned media from PHA stimulated cultures of peripheral mononuclear cells (PHA-MNC-CM) were compared among patients with cancer, patients with non-malignant disease and normal persons. In nine out of 10 cases of cancer with metastasis (including extensive infiltration to surrounding tissues), the activities were much lower than normal persons, whereas in four out of five cases of cancer without metastasis, the activities were almost the same as those of normal persons. The low activities of PHA-MNC-CM from patients with metastatic cancer were not due to the older age of patients, nor did it seem to be attributed to the malnutritional state of patients. When we examined the activity using non-adherent MNC instead of the whole MNC, the activities in patients with metastatic cancer rose up to almost the normal levels. In normal persons the decline of the activities after 3 days of culture were not observed after the removal of adherent cells. Our data indicate that the adherent cells have a suppressive effect on TCGF production in both normal persons and cancer patients, but that the effect may be exaggerated in patients with metastatic cancer.

Cell Adhesion↗
PubMed1983

Peripheral lymphocyte response to PHA and T cell population among atomic bomb survivors.

The percentage of T lymphocytes of atomic bomb survivors showed no change as a function of age or exposure dose. The percentage of T cells was slightly lower in malignant-tumor patients than in the control group, but was significantly higher in the group with chromosomal aberrations than in the control group. The percentages of phytohemagglutinin (PHA)-induced transformation of peripheral lymphocytes decreased significantly with age in the 0 rad control group and the 200+ rad exposure group, particularly so in the latter. The malignant-tumor group also showed lower percentages of PHA-induced transformation than the control group. The percentages of PHA-induced transformation of lymphocytes of the chromosomal-aberration group were significantly depressed as compared with that of the control group.

Chromosome Aberrations↗
PubMed1984

Alloantibodies to PHA-activated lymphocytes detect human Qa-like antigens.

Platelet-absorbed sera were obtained from placental clots after delivery by multiparous women. These sera contained antibodies that react with PHA-activated lymphocytes after the latter are separated from peripheral blood and expanded with interleukin 2. These alloantibodies did not react with resting T lymphocytes, but reacted with B lymphocytes, PHA-activated lymphocytes, or both types of cells obtained from some but not all of the T lymphocyte donors. Reactions against B lymphocytes were associated with anti-Ia-like antibodies on the basis of blockage by turkey antibodies against human Ia. Reactions against PHA-activated lymphocytes that were blocked by turkey anti-beta 2m were classified as 'HT'. Several antibodies were found to give reactions to HT determinants in separate panels of lymphocytes from Tel Aviv and Boston. The reproducibility of the cytotoxicity reactions was 89%. Altogether, 23 of 1100 sera were found to contain these reactions when screened by a panel of cells obtained from 30 individuals of known HLA phenotypes. Correlation coefficients were determined for all reactions, determining three clusters of significant reactivities: sera 965 and 1032 defined HT-2; sera SF48 and 1642 defined HT-3; and sera 1136, 1605, 1014, and 1227 defined HT-4. HT-2 was found to be inherited with HLA in 11 siblings from four families. Some of these antibodies react with antigens (non-HLA) containing beta 2m that were expressed on activated lymphocytes, but not on resting T lymphocytes, and did not react with thymocytes from the same donors of the peripheral lymphocytes. Our findings suggest that the HT alloantigens expressed on lectin-activated lymphocytes are class I differentiation antigens of a system analogous to the murine Qa system.

Antigens, Surface↗
PubMed1984

Cellular interactions and IL2 requirements of PHA-induced human T-lymphocyte colonies.

A number of conflicting proposals have been put forward as to the roles and identities of cooperating cells involved with human T-lymphocyte colony formation. To resolve this conflict, the principal cellular interactions of human T-lymphocyte colonies were analyzed using a two-step culture technique. Through mathematical analysis of cell dose-response curves the requirement for at least two populations of cooperating cells in addition to the colony-forming cell was demonstrated. By removing adherent cells prior to the first but not the second step, colony formation was inhibited, which suggests a restricted role for these cells during the early stages of colony formation. The dependence of the second step on interleukin 2 (IL2) availability implied that IL2-producing cells composed the other population of cooperating cells. We therefore propose that colony formation can be described by the two interdependent reactions of activation (T----T') and proliferation (T'----nT'). The first reaction requires an adherent cell (monocyte) population that together with PHA provides the necessary signals for cellular activation. Cell contact is needed to allow the expression of this adherent cell or interleukin 1 ( IL1 ) activity. As a result of these signals at least two subpopulations of lymphocytes are activated, the T-lymphocyte colony-forming cells themselves ( TLCFC ) and a population of cooperating T cells. These activated T cells interact during the second or proliferative reaction. In response to PHA the cooperating T cells release IL2, thereby enabling the activated TLCFs to proliferate into colonies. Thus for PHA-induced T-colony formation, TLCFCs required the cooperation of adherent cells for the activation reaction and IL2-producing T cells for proliferative reaction.

Agar↗
PubMed1984

Effects of irradiation on PHA-induced T-lymphocyte colonies: differential effects according to the timing of irradiation.

To investigate the effect of irradiation on lymphocyte mitosis we utilized a T-lymphocyte colony assay; this sensitive technique avoided the methodological problems associated with previous techniques such as tritiated thymidine uptake. Irradiation doses in the range of 0.5 to 4 Gy had the effect of decreasing the lymphocytes' capacity to divide as shown by their reduced T-colony-forming ability. This radiosensitivity, however, was found to vary according to the timing of irradiation in relation to the stage of colony growth. Through survival curve analysis it was shown that the colony-forming cells could withstand higher irradiation doses without losing their replicative ability when they were irradiated prior to or during early stages of PHA stimulation. A similar "protection" by PHA stimulation has been well documented for nondividing T-lymphocyte functions but, due to the lack of a suitable methodology, had hitherto not been described for dividing T-lymphocytes. These results provide evidence that the early events associated with PHA stimulation might lead to an improved ability of T-lymphocytes to withstand higher doses of irradiation before mitotic death is registered.

Cell Division↗
PubMed1983

Kinetics and characteristics of murine macrophage-lymphocyte interaction in presence of PHA: appearance of multinucleated giant cells in vitro.

The appearance of cellular associations between macrophages and lymphocytes--which we have denominated macrophage-lymphocyte rosettes--and their kinetic formation in the presence of phytohemagglutinin (PHA) have been studied in B10 A (4R) mice. The greatest number of macrophage-lymphocyte rosettes was found from 6 to 12 hours after incubation with PHA. During this time, 42.38 +/- 10.70 of the total number of macrophages had lymphocytes attached to their membranes. This percentage decreased to 17.33 +/- 2.07% after 24 hours. The activation of macrophages after PHA treatment was tested by the phagocytic capacity of these cells. This activity increased significantly 24 hours after incubation. In our assay, an increase in the appearance of multinucleated giant cells when compared to controls was also observed. When the macrophages were lymphocyte depleted, the appearance of the multinucleated giant cells was significantly lower. The kinetics for these formations are also discussed.

Animals↗
PubMed1981

Bestatin, a new immunomodulator, augments the release of mitogenic factors from PHA-stimulated human lymphocytes.

A new chemically well-defined immunomodulator termed Bestatin was examined for its capacity to interfere with the release of factors from PHA pulsed human peripheral lymphoid cells which are mitogenic for T-cells. The presence of Bestatin, at Concentrations of 0.01-100 microgram/ml, during PHA-pulsing significantly enhanced the subsequent release of mitogenic factors. The highest increase, fourfold, was observed using 10 microgram/ml of Bestatin, Treatment of lymphoid cells with Bestatin alone or pretreatment with this compound before PHA pulsing did not significantly change the subsequent release of these lymphokines.

Adult↗
PubMed1982

Autoimmune thyroiditis in young and old mice: differential effect of high doses of PHA.

Experimental autoimmune thyroiditis (EAT) was used to study the effect of age and PHA in the autoimmune response. EAT was induced in mice by two injections 7 days apart of soluble syngeneic mouse thyroglobulin (MTg) and lipopolysaccharide (LPS) as adjuvant. Thereafter the antibody titre to MTg was determined in the serum and the degree of cellular infiltration estimated in thyroid sections. The results show that in old mice the humoral response is low and no cellular infiltration is found in the thyroid; young mice showed both types of immune response. Phytohaemagglutinin (PHA) was shown to inhibit antibody production when given before the first and second antigen injection, and to suppress completely the cellular immunity against thyroid tissue. When given to old mice a reduction in anti-MTg titre is also seen, but no effect on infiltration is found. However when PHA is only given before the second dose of antigen a stimulation of cellular immunity is seen in contrast to young mice where there is no effect.

Aging↗