Histopathology of the Skin Test Using a Polysaccharide Antigen of the Paracoccidioides Brasiliensis**Institute of Tropical Medicine, “Hospital des Clinicas” and Medical School University of Sao Paulo, Brazil, South America.

The density and distribution of T cells, T helper cells, macrophages and B cells at the site of skin tests with a cytoplasmic Paracoccidioides brasiliensis antigen (paracoccidioidin) was studied at 24 and 48 h post-challenge in 10 patients with the chronic form of paracoccidioidomycosis and in 5 non-infected individuals. The in situ study was carried out using immunoperoxidase techniques and monoclonal antibodies. The controls showed negative skin test. In the patients, the great majority of the cells in the perivascular foci were T cells (CD43-positive cells) making up 47% and 48.6% of the total number of cells at 24 and 48 h respectively. Most of the T cells showed a T helper phenotype (CD45RO-positive cells). Approximately 25% of the cells were macrophages (CD68-positive cells) and there were very few B lymphocytes (CD20-positive cells). The present data on the microanatomy of paracoccidioidin skin test sites were consistent with a delayed type hypersensitivity pattern. Our results were comparable to those reported on skin tests for other granulomatous chronic diseases.

show abstract

Immunohistochemical characterization of mononuclear cells in delayed hypersensitivity reactions toParacoccidiodes brasiliensis (paracoccidioidin test)

Marques

Moscardi-Bacchi

Marques

et al. 1993

Mycopathologia

View full text Add to dashboard Cite

show abstract

Paracoccidioides brasileensis: Cell wall structure and virulence

San-Blas

1977

Mycopathologia

View full text Add to dashboard Cite

Paracoccidioides brasiliensis is the causative agent of paracoccidioidomycosis or South American blastomycosis. Many aspects of the disease and its agent are unknown. One of the most important factors regarding the infection and the host-parasite relationships seems to be the fungal cell wall whose biochemical aspects are reviewed here. Biochemical studies, done mainly by Kanetsuna et al., (21,22), have demonstrated that the yeastlike (Y) and the mycelial (M) forms have chitin as a common polysaccharide, with alpha-1, 3-glucan in the Y form and beta-1, 3-glucan in the M form. These polysaccharides are fibrillar and determine to some degree the fungal shape. Moreover, an amorphous galactomannan is found in the cell wall of the M form. This compound is responsible for the antigenic properties of the cell wall (1). Recent studies (30-33) suggest that the cell wall does not possess a stable chemical structure but a rather changing one, as a function of the environment in which the fungus is grown. At the same time, the cell wall composition seems to correlate with the degree of virulence of the particular strain. From these observations it may be deduced that the constituent polysaccharides of P. brasiliensis cell wall, play an important role in the active protection of the fungus against the defensive mechanisms of the host.

show abstract

The immunology of South-American blastomycosis

Netto¹

1965

Mycopathologia et Mycologia Applicata

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Histopathology of the Skin Test Using a Polysaccharide Antigen of the Paracoccidioides Brasiliensis**Institute of Tropical Medicine, “Hospital des Clinicas” and Medical School University of Sao Paulo, Brazil, South America.

Cited by 7 publications

References 5 publications

Immunohistochemical characterization of mononuclear cells in delayed hypersensitivity reactions toParacoccidiodes brasiliensis (paracoccidioidin test)

Immunohistochemical characterization of mononuclear cells in delayed hypersensitivity reactions toParacoccidiodes brasiliensis (paracoccidioidin test)

Paracoccidioides brasileensis: Cell wall structure and virulence

The immunology of South-American blastomycosis

Contact Info

Product

Resources

About