Polymorphism in the Gene Coding for the Immunodominant Antigen gp43 from the Pathogenic Fungus Paracoccidioides brasiliensis

Abstract

The gp43 glycoprotein is an immune-dominant antigen in patients with paracoccidioidomycosis (PCM). It is protective against murine PCM and is a putative virulence factor. The gp43 gene of Paracoccidioides brasiliensis B-339 is located in a 1,329-bp DNA fragment that includes two exons, a 78-bp intron, and a leader peptide-coding region of 105 bp. Polymorphism in gp43 has been suggested by the occurrence, in the same isolate or among different fungal samples, of isoforms with distinct isoelectric points. In the present study we aligned and compared with a consensus sequence the gp43 precursor genes of 17 P. brasiliensis isolates after sequencing two PCR products from each fungal sample. The genotypic types detected showed 1 to 4 or 14 to 15 informative substitution sites, preferentially localized between 578 and 1166 bp. Some nucleotide differences within individual isolates (noninformative sites) resulted in a second isoelectric point for the deduced protein.The most polymorphic sequences were also phylogenetically distant from the others and encoded basic gp43 isoforms. The three isolates in this group were from patients with chronic PCM, and their DNA restriction patterns were distinct in Southern blots. The nucleotides encoding the inner core of the murine T-cell-protective epitope of gp43 were conserved, offering hope for the development of a universal vaccine.

The mitochondrial genome from the thermal dimorphic fungus Paracoccidioides brasiliensis

“…Paracoccidioides brasiliensis , isolate 18, obtained from a Brazilian patient with chronic PCM, was kindly provided by Dr Rosana Puccia from Universidade Federal de São Paulo, São Paulo, Brazil (Morais et al , 2000).…”

The human fungal pathogenParacoccidioides brasiliensis(Onygenales: Ajellomycetaceae) is a complex of two species: phylogenetic evidence from five mitochondrial markers

“…Culture and storage of the isolates were performed according to Diez et al (1999). Total DNA was extracted from yeast-form cultures using glass beads (Van Burik et al, 1998) or by maceration of frozen cells (Morais et al, 2000).…”

Paracoccidioidomycosis disease (Lutz-Splendore-Almeida disease): Additional workup, differential diagnosis, cure control

“…[31][32][33][34] Multiple targets are used for the detection of P. brasiliensis and P. lutzii DNA such as markers for the coding regions of ribosomal RNA (rDNA) and glycoproteins gp43 and pb27. 32,[35][36][37] PCR performed with primers based on gp43 gene sequences is an excellent instrument and highly sensitive method. 32 Microsatellites can be important markers for the detection P. brasiliensis DNA.…”