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PubMed1992

Phaseolus vulgaris L. var. HUR 15--a potential indigenous source for commercial PHA preparation.

Mitogenic potential of the partially purified lectin from P. vulgaris isolated by ammonium sulphate precipitation was assessed by lymphocyte transformation test (LTT) and was compared with three commercially available phytohemagglutinins (PHA). The blast inducing capacity and mitotic index analysis revealed that this preparation has potential to be used in the indigenous commercial production of PHA which is routinely used for human chromosomal studies from the peripheral blood culture at, at present, is imported.

Dose-Response Relationship, Drug↗
PubMed1992

[Studies of the lymphatic system in mice infected with Trichinella pseudospiralis as well as infected and stimulated by Phytohaemagglutin (PHA-P)].

Mice CFW were infected per os with Trichinella pseudospiralis (150 larvae/mice). The mice were divided in two groups: nonstimulated and stimulated intraperitoneally with PHA-P at dose 10 mg/kg body weight. The animals were killed 7, 14, 21, 28, 42, 56, 70 and 150 day post infection (d.p.i.). Spleen et mesenteric lymph nodes were examined histopathologically (Hematoxylin-Eosin) and histochemically (nonspecific esterase reaction) for differentiation of T lymphocytes. The obtained results reveal that T. pseudospiralis infection caused weak mobilisation of mouse lymphatic system lasting only to 70 day of experiment. In the lymphatic organs of infected mice small number of T lymphocytes were observed mostly between 28 and 56 d.p.i. The intraperitoneally stimulation with PHA-P give rise to caused only little mobilisation of lymphatic tissue and small increase of T lymphocytes number. The obtained results were compared with analogic earlier experiments with T. spiralis infection.

Animals↗
PubMed1976

Spontaneous and PHA-induced rosetting of human blood, tonsil lymphocytes and MLC blasts with sheep, human and horse erythrocytes.

Compared to peripheral blood lymphocytes the ability of human tonsil T cells and MLC blasts to bind sheep, human and horse erythrocytes was found to be increased. Tonsil and MLC T cells were able to bind sheep red blood cells without any cold incubation, i.e. they were 'early' rosettes, and higher percentage of human and horse erythrocyte rosettes were formed by these cells. Low doses of phytohaemagglutinin increased the proportion of rosettes between peripheral blood, tonsil, MLC cells and human and horse erythrocytes. PHA acted only on T cells, and not on B cells, lymphoblastoid B and other cell lines. On the ground of the stronger rosetting property of MLC blasts and tonsil cells, it is likely that the T cells responsible for binding of horse and human erythrocytes after PHA treatment are 'early' or 'active' rosetting cells.

Animals↗
PubMed1992

Influence of acupuncture on the discharge of PHA neurons in the rabbit.

This paper deals with whether the posterior hypothalamus area (PHA) can receive signals from electroacupuncture (EA) at "Neiguan", and whether a relative specificity does exist between acupoints or acupoint and non-acupoint. The neuron activity was recorded extracellularly for analyzing the influence of EA at different acupoints and non-acupoint on the discharge of PHA neurons.

Acupuncture Points↗
PubMed1992

[Study and preparation of Vi-PHA reagent and its application for detection of Salmonella typhi carriers].

Purified S. typhi Vi antigen is sensitized with equal volume of tannic acid treated formalational sheep erythrocytes (SRBC) at a final concentration of 1 microgram/ml. The Vi-passive hemagglutination assay (Vi-PHA) diagnostic reagent is developed to detect Vi antibodies to S. typhi for the detection of chronic carriers after typhoid fever and the screening S. typhi healthy carriers from food-handlers, which is characterized with high sensitivity, strong specificity and good stability. This Vi-PHA reagent is able to detect 1.16 micrograms/ml of Vi antibodies and doesn't make any cross reaction with healthy sera. For the sera of other diseases, the cross rate is only 0.84%. Using this reagent, 19 positive sera (6.93%) are detected from 274 convalescent sera from typhoid fever, 14 convalescents of which are stool-culture S. typhi positive, that persists a positive rate of 73.68%; 3 positive sera are detected from 106 foodhandlers, one of which is stool-culture S. typhi positive. Therefore, the reagent is simple, convenient, rapid and easy to be applicated in basic unit.

Antibodies, Bacterial↗
PubMed1992

Induction of Fc epsilon RII/CD23 on PHA-activated human peripheral blood T lymphocytes and association of fyn tyrosine kinase with Fc epsilon RII/CD23.

Despite the evidence for the expression of Fc epsilon RII/CD23, a glycoprotein that is a low-affinity Fc receptor for IgE, obtained on T cell lines and some pathological T cells, that of Fc epsilon RII/CD23 on normal human T cells is still unclear. We studied the emergence of T cells bearing Fc epsilon RII/CD23 in short-term culture of normal human peripheral blood mononuclear cells stimulated with 15 microliters/ml phytohemagglutinin (PHA). Using two-dimension flow cytometry, more than 10% of Fc epsilon RII/CD23(+) cells were shown to co-express CD3 antigen. Both CD4(+) and CD8(+) T cells expressed Fc epsilon RII/CD23. The expression of mRNA for Fc epsilon RII/CD23 on PHA and IL-4 stimulated PBMC was demonstrated by northern blotting and in-situ hybridization. The mechanism of signal transduction through Fc epsilon RII/CD23 was dissected by transfection of cDNA coding for Fc epsilon RII to the human natural killer-like cell line YT, activation of which was easily detected by the induction of interleukin-2 receptor/p55 (Tac). Cross-linking of Fc epsilon RII/CD23 with H107 anti-Fc epsilon RII monoclonal antibody enhanced IL-2R/p55 expression on YT cells transfected with Fc epsilon RII cDNA (YTSER). A possible involvement of protein-tyrosine kinase in the Fc epsilon RII-mediated signal transduction was studied using YTSER. Fc epsilon RII was physically associated with an src-family tyrosine kinase p59fyn and not with p56lck, which was also found in YT cells. Recently it was reported that p59fyn was associated with T-cell antigen receptor. Our results collectively suggest the multiple function of p59fyn which may be implicated in the Fc epsilon RII-mediated activation signal in YT cells.

Blotting, Northern↗
PubMed1977

[Histone phosphorylation of human lymphocytes after PHA stimulation in relation to age (author's transl)].

Lymphocytes of young and old donors are stimulated by phytohemagglutinin (PHA). The 32P-incorporation into the histones which occurs in the early phase after PHA-stimulation is determined. In lymphocytes of old persons the 32P-incorporation in the histones is diminished by about 50% with respect to the cells of young donors. Furthermore, it could be shown that in the histones prepared from old cells the amount of H1 is much increased. It is postulated that, in old age, the other 4 histones are poorly extractable.

Adolescent↗
PubMed1990

[Post mortem HLA phenotyping of donors of eyes. Evaluation of a serological method of microlymphotoxicity on lymphocytes and PHA lymphoblasts].

To increase the number of HLA typed corneas a microlymphocytotoxicity assay on lymphocytes and PHA lymphoblasts was investigated. A double immunofluorescence technique using magnetic beads coated with anti-T8 (for class I) and anti-DR (for class II) monomorphic antibodies was applied. Blood samples from 50 non selected donors were obtained. HLA class I and class II typing was possible in 74% of the cases. Using PBL's (Peripheral Blood Lymphocytes) HLA class I could be defined in 29 out of 50 Cases and class II in 15 out of 50 cases. On PHA blasts HLA class I and class II antigens could be defined in 32 and 33 out of 50 cases respectively. Mean time of culture was 10 days (6-20). No influence of donor age and post partum time could be observed. By combination of both methods a significant proportion of eye donors could be reliably typed within a short time.

Adult↗
PubMed1990

The rat olivocerebellar system visualized in detail with anterograde PHA-L tracing technique, and sprouting of climbing fibers demonstrated after subtotal olivary lesions.

The rat olivocerebellar climbing fiber system has been investigated at the light and electron microscopic level with anterograde Phaseolus vulgaris leucoagglutinin (PHA-L) tracing. From PHA-L Injections in different parts of the inferior olive labelled axons could be traced to the contralateral cerebellum. Arriving in the deep cerebellar white matter, the olivocerebellar axons ran around and through the cerebellar nuclei. Plexuses of labelled terminal fibers appeared in the cerebellar nuclei, and the density of this innervation was estimated to 1-4 million varicosities per mm3. Ultrastructurally, these boutons engaged in asymmetric synapses with small dendrites. Bundles of labelled fibers continued into the folial white matter, and terminated as climbing fibers in sagittal zones of the cerebellar cortex. Both the cortical and nuclear terminations of the olivocerebellar system are strictly topographically organized. The plasticity of climbing fibers was studied after partial lesions of the inferior olive induced by 3-acetylpyridine. One to 6 months after the lesion, surviving climbing fibers demonstrated extensive sprouting. The newly formed axons originated from parent climbing fiber plexuses, grew in the direction of parallel fibers, and formed terminal plexuses around several neighbouring Purkinje cells. As normal climbing fiber terminals, these terminals formed asymmetric synapses with spines of proximal Purkinje cell dendrites, and evidence by Benedetti et al. (1983) shows that the regenerated innervation is electrophysiologically functional. It is suggested that denervated Purkinje cells release a trophic substance, which stimulate surviving climbing fibers to sprouting, axonal growth and synapse formation.

Animals↗
PubMed1990

[Technical note on the isolation of HIV from peripheral lymphomonocytes: use of PHA].

As a part of ongoing study about the role that different technical factors may play in influencing the sensibility of HIV isolation procedures, the authors have evaluated the effects of PHA stimulation of infected cells on HIV replication in cell cultures. Data presented demonstrate that the use of PHA in cell cultures for HIV isolation causes a slower viral replication and, in some cases, inhibits HIV growth.

Cell Division↗
PubMed1986

Heterogeneity among T cells in intracellular free calcium responses after mitogen stimulation with PHA or anti-CD3. Simultaneous use of indo-1 and immunofluorescence with flow cytometry.

Measurement of intracellular ionized calcium concentrations ([Ca2+]i) has been indispensable in elucidating the central role of [Ca2+]i as a trigger of cellular responses to activating stimuli. Such studies have employed the dye quin2, which has not been readily adapted to analysis of individual small cells. We show here that the calcium response of large numbers of single cells can be analyzed with the use of flow cytometry and the recently described dye, indo-1. Such analyses demonstrate for the first time the heterogeneous nature of the [Ca2+]i response to mitogenic stimuli within populations of peripheral blood lymphocytes (PBL). By simultaneous quantitation of one- or two-color surface immunofluorescence labels, some of this heterogeneity of [Ca2+]i response in PBL is shown to be related to cellular immunophenotype. Almost all T cells responded to anti-CD3 antibody; however, the response is greater among CD4+ than CD8+ cells, and within the CD4+ population the rate of response to stimulation by antibody to CD3 differed between subpopulations defined by expression of the common leukocyte marker p220. In contrast, not all T cells responded to phytohemagglutinin (PHA), even at very high doses. As with anti-CD3, after stimulation with PHA, CD4+ cells showed a larger proportion of responding cells than did CD8+ cells. In separate experiments, indo-1 was found not to impair reproductive viability of PBL, thereby providing the potential for analysis of functional activity after the separation of cells by sorting on the basis of the [Ca2+]i response to stimuli. Mixing experiments indicated that a response of a subpopulation representing as little as 0.3% of total cells could be readily detected. Thus, the flow cytometric assay with indo-1 is the first technique that allows the quantitative analysis of response differences of small subpopulations of cells and intercellular variation in [Ca2+]i.

Antibodies, Monoclonal↗
PubMed1978

The persistent PHA-responsive population in the mouse thymus. II. Recirculatory characteristics and immunological properties.

Experiments were performed to ascertain whether the persistent PHA-responsive cell population found in mouse thymus grafts was capable both of localizing to peripheral lymphoid organs when deliberately injected into suitable recipient mice, and of responding to antigenic stimulation. It was shown that the persistent population could not be found in large numbers in recipient spleens or lymph nodes at late time after transfer. These cells could, however, be found in large numbers in the peripheral blood of recipients. Thus they appeared to be able to circulate in the blood but not be able to extravascularize in lymphoid organs. Since these cells did not localize to spleen or lymph nodes, it was not surprising to find that they did not respond to the skin sensitizing agent oxazolone in draining lymph nodes or spleen, or to histocompatibility antigens (graft-vs-host). When tested against allogeneic cells in vitro (mixed lymphocyte reaction), it was shown that the persistent population was over nine times less reactive than in its reactivity to PHA, when compared to the non-persistent population. The functional significance of these thymocyte populations is discussed.

Animals↗
PubMed1977

Ther persistent PHA-responsive population in the mouse thymus. II. Recirculatory characteristics and immunological properties.

Experiments were performed to ascertain whether the persistent PHA-responsive cell population found in mouse thymus grafts was capable both of localizing to peripheral lymphoid organs when deliverately injected into suitable recipient mice, and of resonding to antigenic stimulation. It was shown that the persistent population could not be found in large numbers in recipient spleens or lymph nodes at late time after transfer. These cells could, however, be found in large numbers in the peripheral blood of recipients. Thus they appeared to be able to circulate in the blood but not able to extravascularize in lymphoid organs. Since these cells did not localize to spleen or lymph nodes, it was not surprising to find that they did not response to the skin sensitizing agent oxazolone in draining lymph nodes or spleen, or to histocompatibility antigens (graft-vs-host). When tested against allogeneic cells in vitro (mixed lymphocyte reaction), it was shown that the persistent population was over nine times less reactive than in its reactivity to PHA, when compared to the non-persistent population. The functional significance of these thymocyte populations is discussed.

Animals↗
PubMed1986

[Inhibitory serum factors in MLR and in PHA-stimulation in sera from normal, allogenic hyperimmunized and transplantation tolerant mice].

Sera from normal, allogeneically hyperimmunized and transplantation tolerant mice show an inhibitory effect on MLR and PHA stimulation. After gel chromatography these inhibitory factors are preferably found in fraction III for MLR (MW 250-750 KD) and III and IV for PHA stimulation. These factors are not identical with the IL-2 inhibitor. A specific inhibitory component with a MW of about 1000 KD is found in sera from transplantation tolerant mice. This suppressor factor could have a synergistic function in induction of specificity and activity of suppressor cell.

Animals↗
PubMedDate not supplied

[Cellular interactions in the lymphocyte response to PHA in old people].

Peripheral blood lymphocytes (PBL) from the same number of old subjects (OS) and young subjects (YS) have been separated into subpopulations of T cells (T1 and T2 fractions) and B cells. Phagocytes were removed by carbonyl iron. The recovery in T1 is reduced in the OS. Their PHA response is inhibited by monocytes but not by polynuclears (PN). The response of their peripheral T cells is not reduced but it is not enhanced by adding PN. There is a normal T-B cell interaction in the response to PHA. It is suggested that the impaired PBL response to mitogens is secondary to the reduction of their content in T1 lymphocytes.

Aged↗
PubMed1977

Studies on T cells in newborns. Higher reactivity of umbilical cord blood lymphocytes to PHA as measured by whole blood microtechnique.

The capacity of human foetal lymphocytes to respond to PHA and to form E-rosettes have been compared with data from adult individuals. For this purpose a microculture system that uses whole blood and avoids the problems of lymphocyte separation, has been developed. Foetal lymphocytes reached optimal stimulation with lower dosis of PHA (31,2 microgram/ml) as compared with adult cells (125-252 microgram/ml). However their quantitative response (measured by 14C-thymidine uptake) was equal in both groups. In addition, peripheral T cells (E-rosetting cells) reached values of 36.47 +/- 9% in newborn and 49.6 +/- 10% in normal adult controls. These results are discussed as to the status and development of cellular inmunity in human foetus.

Adult↗
PubMed1977

Variation of lymphocyte classes and their PHA-P reactivity with age.

Absolute and relative values of lymphocyte classes in peripheral blood of 19 to 80 year-old, apparently healthy donors were determined simultaneously by means of the cytocentrifuge method. Lymphocytes were classed as cells which formed rosettes with neuraminidase-treated sheep erythrocytes (T cells), as cells which bound C3b-loaded zymosan particles (B cells), or those which showed both characteristics (doubly marked cells = D cells). Cells which exhibited none of the above characteristics were classed as O cells. The reproducible absolute valued of T, B, D, and O cells showed a statistically significant decline with age, similarly to a decline in the total lymphocyte counts. The relative values in per cent, however, remained constant over the whole age spectrum. In 1 hour experiments, the acid phosphatase activity of non-stimulated and of PHA-P-stimulated cells decreased with age, the latter, however, less than did the controls. Therefore, the stimulating effect increased significantly. When cells were stimulated for a period of 4 hours, the stimulating effect decreased with age, indicating an age-dependent loss of longer lasting reactivity to PHA-P controlled by acid phosphatase activity.

Acid Phosphatase↗
PubMed1978

Contribution of lymphocytes bearing Fcgamma receptors to PHA-induced cytotoxicity.

Lymphocytes participating in PHA-induced lysis of chicken erythrocytes were characterized by means of cell fractionation methods. Selective depletion of, or enrichment in, E-rosetting cells indicated that the effector cell population was heterogenous, consisting of both T and non-T lymphocytes. Most effector cells, however, were shown to bear Fcgamma receptors detected by the formation of erythrocyte-antibody (EA) rosettes, but to lack C3 receptors. This distribution of effector cells among tonsils, peripheral blood and thoracic duct lymph paralleled that of EA-rosette forming cells but not that of T or B cells. Addition of aggregated IgG resulted in a moderate decrease of PHA cytotoxicity. However, almost complete inhibition was achieved within a few hours of contact between effectors cells and insoluble immune complexes. The results support the hypothesis that cytotoxic capacity is associated with the presence of Fcgamma receptors on the cell surface.

Binding Sites↗