Ultrastructure of lymphocytes from patients with paracoccidioidomycosis in the lymphocyte transformation test by phytohemagglutinin

Costa, João Carlos da; Conçalves, Renato P.; Pagnano, P M G; Bechelli, L. M.

doi:10.1007/bf00443518

Cited by 10 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various hypotheses could be made to explain the immunoregulatory disturbances, for example, (i) the increased production of plasma factors that inhibit cellular immunity [8,16], (ii) immunosuppressor factors produced by the fungus, as seen in candidosis [17], (iii) immunosuppression due to the action of immune complexes [1], (iv) predisposing genetic factors, (v) active suppression by suppressor T cells and/or macrophages I18] and (vi) deficiency in interleukin-2 and/or interleukin-1 production as seen in lepromatous leprosy [13,26].…”

Section: Discussionmentioning

confidence: 99%

Mononuclear cell subsets in patients with different clinical forms of paracoccidioidomycosis

Mota

Peraçoli²,

Mendes³

et al. 1988

Med Mycol

View full text Add to dashboard Cite

Seventy untreated paracoccidioidomycosis patients, 15 with the acute or subacute form of the disease and 55 with the chronic form, were compared with two normal control groups of the same age range. Peripheral blood mononuclear cell subsets were defined by monoclonal antibodies directed at total T cells, helper/inducer and suppressor/cytotoxic T cell subpopulations; B cells, conical thymocytes and monocyte/null cells. Both groups of patients showed an increased number of monocyte/null cells, a low helper/suppressor ratio and a reduced percentage of total T cells and their helper/inducer subsets. In addition patients with the acute form of the disease exhibited high levels of suppressor/cytotoxic T cells and B cells. These findings are of importance in our attempts to understand the pathogenesis of this mycosis and also to evaluate its prognosis in individual patients.Paracoccidioidomycosis, a chronic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis, is the most prevalent human systemic mycosis in Latin America. The disease may be classified into three clinical forms: (i) the acute or subacute form, with intense involvement of the mononuclear phagocyte system which affects young people, (ii) the chronic form, with an insidious evolution and involvement of one or more organs or systems, which generally affects adult males and (iii) the residual sequelar form, with manifestations related to cicatrization of old lesions [14].

show abstract

Section: Discussionmentioning

confidence: 99%

Mononuclear cell subsets in patients with different clinical forms of paracoccidioidomycosis

Mota

Peraçoli²,

Mendes³

et al. 1988

Med Mycol

View full text Add to dashboard Cite

show abstract

“…Over the last few years, attempts have been made to understand the regulatory mechanisms of CMI responses in paracoccidioidomycosis. Serum factors (34), immune complexes (1), fungal products or metabolites (11,13,42), and induction of suppressor cells (27,28) have all been proposed to be responsible for the observed suppression of the CMI responses to P. brasiliensis in human disease as well as in animal models.…”

Section: Discussionmentioning

confidence: 99%

Induction of antigen-specific T suppressor cells by soluble Paracoccidioides brasiliensis antigen

Jimenez-Finkel

Murphy

1988

Infect Immun

View full text Add to dashboard Cite

In naturally acquired paracoccidioidomycosis, patients have depressed in vivo and in vitro cell-mediated immune (CMI) responses to Paracoccidioides brasiliensis antigen. In addition, it has been reported that these patients have significant levels of circulating paracoccidioidal antigen in their sera. The primary purpose of this investigation was to assess the effects of P. brasiiensis antigen on the CMI responses in a mouse model. On the basis of findings with other fungal agents, we predicted that circulating paracoccidioidal antigen may be inducing suppressor cells which modulate the CMI response. In this study, we show (i) that a soluble P. brasiliensis culture filtrate antigen (Pb.Ag) emulsified in complete Freund adjuvant and injected subcutaneously into mice induces reasonably high levels of delayed-type hypersensitivity (DTH) in CBA/J mice; (ii) that Pb.Ag elicits DTH reactions specific for P. brasiliensis when injected into footpads of immunized mice; and (iii) that an intravenous injection of Pb.Ag induces a population of lymph node and spleen cells which, upon adoptive transfer, suppress the afferent limb of the DTH response to paracoccidioidal antigen. The afferent suppressor cells can be detected in spleens as early as 5 days after Pb.Ag treatment, are present in significant numbers by 7 days in both spleens and lymph nodes, and are virtually absent by 14 days. In contrast, at 14 days after antigen injection, efferent suppressor cells were detected in spleens and lymph nodes. The Pb.Ag-induced afferent suppressor cells specifically inhibit the antiparacoccidioidal DTH response. They are nylon woolnonadherent cells, and their activity is abrogated by anti-Thy-i and complement treatment, indicating that they are T lymphocytes. The phenotype of these afferent suppressor T cells is L3T4+ Lyt-1+2-I-J+. The Pb.Ag-specific suppressor cells described in this paper are similar to the Tsl cells in the azobenzenearsonate, 4-hydroxy-3-nitrophenyl acetyl, and cryptococcal models of suppression of the DTH response and to the afferent suppressor cells in the dinitrofluorobenzene contact sensitivity system.

show abstract

“…The horizontal lines represent the median. 4. Fungal antigen levels in serum samples from one patient with the acute severe form of Pcm over a period of 9 months after diagnosis.…”

mentioning

confidence: 99%

Antigenemia in paracoccidioidomycosis

Freitas-da-Silva

Roque‐Barreira

1992

J Clin Microbiol

View full text Add to dashboard Cite

Severe forms of paracoccidioidomycosis (Pcm) are accompanied by intense immunological involvement characterized by depression of the cell-mediated immune response and by high levels of antibodies in serum with no protective function. These changes can be reversed by antifungal treatment. It has been suggested that antigens of Paracoccidioides brasiliensis released into the circulation during the active phase of the disease may be involved in the genesis of the changes in the immune response. In the present study, we evaluated the antigenemia of patients with Pcm using a competitive enzyme-linked immunosorbent assay (ELISA-c) capable of detecting 6 ng of antigen per ml of serum. Twenty-seven of 88 serum samples tested gave positive results, with the highest frequency of positivity being detected in patients with the severe acute form of the disease; these patients had the highest antigen levels (0.03 to 3.4 micrograms/ml). Follow-up of one case showed a correlation between antigen levels in serum and evolution of the disease. False-positive reactions were observed in sera from patients with histoplasmosis, aspergillosis, and cryptococcosis. The results indicate that the described method has potential for clinical application, especially with respect to the evaluation of disease activity. Quantification of fungal antigens in the serum of patients with active Pcm represents an objective parameter for the study of the physiopathology of the disease.

show abstract

Ultrastructure of lymphocytes from patients with paracoccidioidomycosis in the lymphocyte transformation test by phytohemagglutinin

Cited by 10 publications

References 3 publications

Mononuclear cell subsets in patients with different clinical forms of paracoccidioidomycosis

Mononuclear cell subsets in patients with different clinical forms of paracoccidioidomycosis

Induction of antigen-specific T suppressor cells by soluble Paracoccidioides brasiliensis antigen

Antigenemia in paracoccidioidomycosis

Contact Info

Product

Resources

About