Generation of Intersectin Homolog Cin1 Isoform-Specific Mutants in Pathogenic Fungus Cryptococcus neoformans

Abstract

Cryptococcus neoformans is an opportunistic fungal pathogen that causesmeningoencephalitis in immunocompromised individuals such as those undergoing solid organtransplant, receiving immunosuppressive therapy, or those with HIV/AIDS. This fungus exhibitsthe propensity for the human central nervous system, thus studies of this neurotropism are animportant component of addressing the fungal virulence mechanism. In a previous study, wefound that C. neoformans contains Cin1, a homolog of human intersectin ITSN1, and that one ofthe two isoforms, Cin1-S, exhibits a survival advantage in the brain of experimental animals. Totest the hypothesis that Cin1 may play a role in fungal neurotropism, mutant strains expressingthe Cin1-L isoform are needed. The present study is to create a Cin1-L mutant allele linked toantibiotic resistance and transform the wild type strain to generate Cin1-L mutants expressingonly Cin1-L. This newly generated strain will be evaluated in experimental animals, eitherindividually or in combination with the Cin1-S or the wild type strains. A partial CIN1-L mutantallele linked to neomycin resistance was obtained and the majority of the 52 genetictransformants contain the recombinant gene contracts and the loss of the wild type CIN1 gene.Efforts are underway to verify that these transformants contain specific mutants that express onlythe long isoform of Cin1 (Cin1-L).