Production and characterization of monoclonal antibodies reactive with the mycelial and yeast phases ofPenicillium marneffei

Abstract

A definitive tissue diagnosis of Penicillium marneffei is hampered by a microscopic similarity to the yeast form of Histoplasma capsulatum and Cryptococcus neoformans. In order to obtain a better discrimination for accurate diagnosis, monoclonal antibodies (MAbs) were produced from hybridomas raised from Balb/c mice immunized with mycelial culture filtrate. By indirect immunofluorescent or immunoblot analysis, one immunoglobulin (Ig) G1 (3C2) MAb and three IgM (8B11, 3B9 and 8C3) MAbs were found to react strongly with P. marneffei antigens. In the immunoblots, the MAbs 8B11 and 3B9 reacted most strongly with a high molecular weight component (> 200 kDa) produced during either the mycelial or yeast phase of fungal growth. The immunoreactive epitopes for these two IgM MAbs were most likely associated with carbohydrate moieties, judging from their susceptibility to periodate oxidation and concanavalin A binding. This is in contrast to the immunoreactive epitopes for the MAbs 8C3 and 3C2, which were resistant to destruction by periodate treatment and did not bind to the lectin. Judging from immunofluorescent intensity, the three IgM MAbs could react strongly with the yeast cells present in the tissue biopsies of patients with P. marneffei infection.

Development and characterization of an immunochromatographic test for the rapid diagnosis of Talaromyces (Penicillium) marneffei

“…Tests utilizing monoclonal antibodies (MAbs) against the 76-kDa and 62-kDa of exoantigen derived from T . marneffei mycelial culture filtrate have low specificity [ 16 , 21 ], which is consistent with prior findings of significant cross reactivities between the antigens of T . marneffei and of other common pathogenic fungi including Aspergillus fumigatus , Candida albicans , Cryptococcus neoformans , H .…”

Characterization of a novel yeast phase-specific antigen expressed during in vitro thermal phase transition of Talaromyces marneffei

“…Several antigenic glycoproteins from cell wall associated and secreted forms of T. marneffei are readily isolated from its crude protein extracts. For example, concanavalin A recognize mannose moieties in both mycelial and yeast phase unidentified antigens of T. marneffei 30 . Furthermore, the cell wall mannoprotein Mp1p is differentially expressed in both the mycelial and yeast phases of T. marneffei 31 .…”