Effect of phorbol myristate acetate (PMA) and ionophore A23187 on interleukin-2 levels and proliferation of activated T lymphocytes from patients with lepromatous leprosy.

The immunodeficiency present in patients with lepromatous leprosy is characterized by the limited proliferation of T lymphocytes, and is explained in part by the impaired synthesis of interleukin-2 (IL-2). Diacylglycerol (DAG) and calcium produce the activation of PKC, ERK and JNK kinases, implying a normal IL-2 response. Phorbol esters, such as PMA, can substitute for DAG and are mitogenic to human T and B cells activating several cytokine-encoding genes. Ionophore A23187 increases calcium permeability across the cellular membrane to the cytosol of lymphoid cells and is considered a co-mitogen of T lymphocytes. Here we report that: 1) PHA-activated T lymphocytes from LL patients can be separated in vitro into two groups: a) responders (R) with a stimulation index (SI) of > 10 and (b) nonresponders (NR) with a SI of < 10. 2) The proliferative responses of cells from LL(R), LL(NR) and normal subjects were measured after being stimulated with: I, PHA, PMA, PMA + I PHA + PMA and PHA + PMA + ionophore (PPI). The most important result occurs in LL(NR) patients whose cells did not respond to PHA stimulation but increased to normal levels of proliferation when they were stimulated with PMA. Furthermore, the three groups, (NR, R and normals) strongly increased their responses when they were incubated with PPi. 3) Finally, Il-2 concentrations in the supernatants of cultures of T lymphocytes from LL(NR), LL(R) and controls were relatively low when they were incubated with PHA or PMA, but the addition of ionophore to PMA and the combination of PHA + PMA strongly increased the production of IL-2 in all of them, reaching the optimum IL-2 concentration when PPI is used. It can be concluded that the use of PMA, analogous to DAG, and ionophore A23187 (calcium increaser) in cultures of mitogen-activated T lymphocytes from LL patients induced the expression of the IL-2 gene, thus correcting the inadequate proliferation of T cells from LL patients.

Recognition of Mycobacterium leprae antigens with antibodies present in sera from patients with lepromatous leprosy.

A great diversity of antigens from Mycobacterium leprae have been described. One practical approach should be to utilize them as markers to indicate when a household contact is at risk of becoming infected and then moving to an active form of leprosy. For this purpose, sonic extracts of M. leprae were fractionated in 10% SDS-PAGE under reducing conditions. The fractionated proteins were then transferred to nitrocellulose sheets and incubated with sera from lepromatous leprosy cases, their contacts, and normal subjects in order to reveal the frequency of antigen recognition of each set of sera. The results showed that sera from lepromatous leprosy patients frequently recognized two proteins, one of approximately 28 kDa and the other of approximately 65 kDa, when compared with the sera from normal subjects. The contacts frequently recognized an approximately 16-kDa antigenic band, while sera from normal subjects recognized one protein of approximately 18 kDa. According to the results, the four recognized proteins from M. leprae can be considered markers of the above conditions (approximately 65 kDa, approximately 28 kDa for lepromatous leprosy, approximately 16 kDa for contacts, and approximately 19 kDa for normal subjects). From these, an easy serological test, such as an ELISA, can be developed to predict if a contact is moving toward lepromatous leprosy before detection of the actual clinical signs or symptoms.

Use of human skin to demonstrate antinuclear antibodies in lepromatous leprosy patients.

A common finding in the sera of leprosy patients is the presence of antinuclear antibodies (ANA), but their specificity for autologous antigens is unknown. The aim of this work was to investigate the reactivity of these ANA toward the cell nuclei of human skin. ANA were investigated in the sera of 35 patients with lepromatous leprosy by immunofluorescence reactions performed with sections of human skin biopsies (autologous from each patient and healthy human skin obtained from plastic surgery procedures), and compared with the results obtained when rat liver was used as substrate. ANA titer, immunofluorescence pattern, immunoglobulin classes (IgG and IgM) and complement-binding capability were also investigated. When human skin sections were used as substrates, 30 out of 35 patients (85.7%) gave positive ANA tests; most of them gave a 1:4 to 1:16 titer for IgG with an annular pattern and 1:4 for IgM with an annular or a granular pattern. ANA of 30 patients bound C1q and 14 bound C3. However, when rat liver sections were used as substrates only 9 out of 35 cases (27.1%) gave positive ANA tests. These results show that human skin sections are a better substrate to demonstrate the ANA present in the sera of patients with lepromatous leprosy. Their significance in the pathogenesis of tissue damage remains to be investigated.

Depressive effect of plasma on lymphocyte transformation in nodular lepromatous leprosy.

Lymphocytes from 20 patients with NLL were cultured stimulated with PHA in presence of autologous and homologous plasma; the same procedure was carried out with lymphocytes from 20 healthy people, utilized as controls. A diminished capacity of transformation was noticed when lymphocytes, both from patients and controls, were cultured in plasma from NLL patients, this suggesting the presence of a plasmatic inhibitor factor. This effect was particularly noticeable in 8 cases (40%) of the studied patients. Regarding the nature of the plasmatic factor, the concentration of C reactive protein, rheumatoid factor, alpha, beta and gamma globulins, did not show any correlation with the presence of the depressive activity. It seems that at least in some cases, the impaired lymphocyte transformation observed in NLL patients, can be due to an immune complex present as a plasma factor, rather to an intrinsic defect in lymphocytes.

[Phagocytosis of Candida albicans by polymorphonuclear leucocytes from patients with nodular lepromatous leprosy]. / Phagocytose de Candida albicans par des leucocytes polynucléaires obtenus de malades atteints de lèpre lépromateuse nodulaire.

Patients suffering from nodular lepromatous leprosy are deficient in cellular immunity but may not be more susceptible to other infections. Therefore it is possible that other defense mechanisms are operational in dealing with other infectious agents these patients may be exposed to. In this report, the phagocytic and fungicidal activity of polymorphonuclear (PMN) cells against Candida albicans was examined using PMN from 20 nodular lepromatous patients and from 20 healthy subjects (controls). The method used was that of PMN adherence to glass. The phagocytic activity was evaluated after 15 mn and 45 mn. We observed that there was phagocytized by 94 % of the PMN from patients and by 95 % of the PMN from the controls. The phagocytic index of the yeasts ingested by the PMN were 4.47 and 4.10 for, respectively, patients and controls. The frequencies of yeasts killed by PMN from patients and controls were, respectively, 29.6 and 29.4 %. The results indicated that PMN from patients and healthy controls had the same capacity to phagocytize and to destroy yeasts of C. albicans.

Perfil inmunologico del enfermo con lepra lepromatosa nodular. Revision del tema y estudio de 70 pacientes del Instituto Dermatologico de Guadalajara. / Immunological profile of the patient with nodular lepromatous leprosy. Review of the subject and study of the 70 patients of the Instituto Dermatologico de Guadalajara

Se estudiaron diversas constantes inmunologicas en dos grupos de pacientes con lepra lepromatosa nodular del Instituto Dermatologico de Guadalajara. El grupo I consto de 50 pacientes y el grupo II de 20 pacientes. Al primer grupo se le estudio la inmunidad humoral por medio de la valoracion de las inmunoglobulinas G, A, M, D, E y el componente C3 del complemento; se investigaron ademas proteinas anormales por electroforesis y proteina G-reactiva (PCR). Al grupo II se le valoro la inmunidad celular por medio de la respuesta de los linfocitos T al estimularse con fitohemaglutinina. En 70% de los pacientes del grupo I presentaron hipergammaglobulinemia de tipo IgG, IgA o IgM. El 34% de los pacientes del grupo II presentaron factores plasmaticos depresores de la transformacion blastoide, tanto de los linfocitos propios como de los alogenicos