Effect of AY 9944 and chlorpromazine on Concanavalin A-induced stimulation of human lymphocytes

Hypogammaglobulinemia during antipsychotic therapy

Hypogammaglobulinemia in a 22-year-old woman with brief psychotic disorder developed during antipsychotic therapy. Severe decreases in immunoglobulin IgM, IgG, and IgA concentration in serum were observed 4 months after the treatment with chlorpromazine (CPZ) and the other types of antipsychotics. Neither physical diseases nor family history for immunological disturbances was seen. No clinical symptoms in relation to immunological disturbances (i.e. infectious disease), were noted. Gammaglobulin levels in serum returned to a normal range after a replacement of chlorpromazine to timiperone. The hypogammaglobulinemia in the present case was considered to be due to the inhibition of gammaglobulin synthesis by CPZ.

Immunomodulating Effects of Various Phenothiazines and Related Tricyclic Compounds in Vitro and in Vivo

A biotechnological approach to the immunomodulating ability of various phenothiazines and related tricyclic compounds in vitro and in vivo was made. The effect of these compounds was studied on various mononuclear leukocyte functions such as antibody-dependent cell-mediated cytotoxicity, blast transformation of lymphocytes by three mitogens, phytohemagglutinin, concanavalin A and pokeweed mitogen (PWM), rosette formation with erythrocytes and with antibody coated erythrocytes (EA), as well as on polymorphonuclear leukocyte functions including phagocytosis and chemiluminescence emission. Moreover, the ability of these compounds to modulate the bioluminescence emission capacity of Escherichia coli cloned with lux genes was measured. Also in vivo studies were made by measuring the number of haemolytic plaque forming cells in the spleen of mice after drug administration.

The electrochemical structure of these tricyclic compounds was shown to be in good correlation with their immunomodulating activity on all the functions except EA rosette formation and on blast transformation by PWM showing the role of charge transfer complex formation in the drug-target cell interaction.

These results suggest that the biological effectiveness of phenothiazines and related tricyclic compounds can be presumed from their electrochemical properties and a tricyclic compound with a given biological effect can be theoretically designed.

Dissociation of immunosuppression by chlorpromazine and trifluoperazine from pharmacologic activities as dopamine antagonists

Neuroleptic compounds may affect the immune system through a variety of mechanisms. Most possess a complex pharmacology, which makes specific, causal relationships difficult to discern. In this study, a series of experiments was performed to examine the effects of dopamine antagonists on a battery of immunologic parameters. Mitogen-induced lymphocyte proliferation in vitro was inhibited by haloperidol, chlorpromazine, and trifluoperazine at 10, 1 and 1 microM concentrations, respectively. Sulpiride and metoclopramide had no direct effect in vitro. In vivo lymphocyte proliferation was significantly reduced by chlorpromazine at the highest tested doses (12.5 and 15 mg/kg) and by trifluoperazine at the highest tested dose (30 mg/kg). All other dopamine antagonists had no significant effect on in vivo lymphocyte proliferation. A murine graft vs host (GVH) response was unaffected by haloperidol, sulpiride, and metoclopramide. Chlorpromazine and trifluoperazine exhibited significant inhibition of the GVH response at the highest doses only (15 and 30 mg/kg, respectively). In a picryl chloride induced delayed type hypersensitivity (DTH) assay, haloperidol, metoclopramide, and sulpiride had no effect. However, both chlorpromazine and trifluoperazine significantly reduced DTH-induced paw swelling at the higher doses (7.5 mg/kg, and 10 and 30 micrograms/kg, respectively). These studies indicate that the more specific dopamine antagonists (e.g. sulpiride, metoclopramide, and haloperidol) do not share the immunologic profiles of chlorpromazine and trifluoperazine, suggesting that these effects of chlorpromazine and trifluoperazine are not related to their dopamine antagonist properties.

A comparison of the effects of chlorpromazine and more selective histamine and 5-hydroxytryptamine antagonists on human IgG synthesis in vitro

We have shown previously that chlorpromazine, a drug associated with immunological abnormalities in vivo, significantly potentiates pokeweed mitogen (PWM)-stimulated IgG synthesis by human peripheral blood mononuclear cells (PBMC) in culture. Chlorpromazine is a pharmacological antagonist of histamine and 5-hydroxytryptamine (5-HT) and thus may exert its immune-enhancing effects by competing with these amines for their respective receptors, which are known to be present on lymphocytes. In this report we show that histamine and 5-HT are present at micromolar concentrations in PBMC cultures. To examine the role of histamine and 5-HT in chlorpromazine-induced enhancement of IgG synthesis we incubated PWM-treated cells with a range of selective histamine and 5-HT antagonists, and with the amines added to cultures either alone or in combination with chlorpromazine. The H1 antagonists mepyramine and promethazine and the H2 antagonist cimetidine had no significant effect on IgG synthesis. The combined 5-HT1/5-HT2 antagonists methysergide and methiothepin also failed to modulate synthesis. Neither histamine nor 5-HT at concentrations up to 100 microM modulated IgG synthesis, nor did they abrogate the enhancement of IgG synthesis induced by chlorpromazine. We conclude that the modulation of IgG synthesis in vitro by chlorpromazine cannot be attributed to an interaction of this drug with lymphocyte receptors for histamine and 5-HT. Other possibilities for the mechanism of action of this drug on immune function are discussed.

Human psychoneuroimmunology today

Studies in human psychoneuroimmunology began around 1919, but a systematic approach wasn't used until the work of Solomon in the 1960s. Recently, the new specialty has achieved relative independence due to considerable data acquisition. Stress research has revealed relationships between neuroendocrine and immune changes. In parallel, increasing evidence of immunological alterations in psychiatric diseases has expanded the field; presently, immunological correlates of psychosomatic diseases and personality are sought. On the other hand, while immunological disease has been psychologically assessed for many years, a clear-cut link between psyche and immunological changes has yet to be shown. This fact, along with the therapeutic implications of advancing knowledge, will influence strongly the future trends of psychoneuroimmunology. Concepts emerging from the study of this field will be of heuristic value to both psychiatry and immunology and will help define new and expanded limits for both disciplines.

Inhibition by chlorpromazine of lymphokine-specific mRNA expression in human thymocytes

This study was designed to determine the effect of the phenothiazine chlorpromazine (CPZ) on the activation of human thymocytes. We provide evidence that CPZ inhibits the accumulation of mRNA specific for the lymphokines, interleukin 2, interferon-gamma, tumor necrosis factor alpha and the proto-oncogene c-myc; by contrast, the accumulation of mRNA specific for the alpha chain of the interleukin 2 receptor and the subsequent early expression of Tac antigen on the cell surface is not inhibited by CPZ. The inhibition of the expression of lymphokine-specific mRNA results in a decrease in interferon-gamma synthesis and in inhibition of thymocyte proliferation as determined by the incorporation of [3H]thymidine. In addition, we show that activation of protein kinase C (PKC) in human thymocytes by 12-O-tetradecanoyl phorbol 13-acetate (TPA) causes the phosphorylation of a protein of a molecular mass of approximately 75 kDa. The function of this protein is as yet not defined, but it is possible that it plays a role in the transduction of the signals to the nucleus which in turn elicit the expression of the genes coding for c-myc and for the lymphokines required for thymocyte activation. We also demonstrate that CPZ, like the immunosuppressant drug cyclosporin A does not inhibit the phosphorylation of the 75-kDa protein which is induced by the activation of PKC by TPA and does not affect phosphoinositide breakdown, indicating that it exerts its effect at a site distal to the activation of PKC. These observations demonstrate that CPZ has an immunoregulatory function in addition to its psychotropic activity.