title: Tc45, a dimorphic Trypanosoma cruzi immunogen with variable chromosomal localization, is calreticulin.
abstract: We demonstrate that Tc45, a polypeptide described as an immunogenetically restricted Trypanosoma cruzi antigen in mice, is calreticulin, a dimorphic molecule encoded by genes with variable chromosomal distribution. Previously we showed that IgG from A.SW (H2s) mice immunized with T. cruzi trypomastigotes or epimastigotes and sera from infected humans recognize Tc45, a 45 kD parasite polypeptide. Herein we describe the cloning, sequencing, and expression of the Tc45 gene. A 98% homology in the deduced amino acid sequence was found with a T. cruzi calreticulin-like molecule and 41% with Leishmania donovani and human calreticulin. In the T. cruzi CL Brener clone and in the Tulahuén strain, the gene is located in two and four chromosomes, respectively. Calreticulin was detected in several T. cruzi clones, in the Tulahuén strain, and in T. rangeli, displaying alternative 43 and 46 kD forms.
authors: Program de Inmunología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago.
authors: J C
authors: JC
authors: Aguillón
authors: L
authors: L
authors: Ferreira
authors: C
authors: C
authors: Pérez
authors: A
authors: A
authors: Colombo
authors: M C
authors: MC
authors: Molina
authors: A
authors: A
authors: Wallace
authors: A
authors: A
authors: Solari
authors: P
authors: P
authors: Carvallo
authors: M
authors: M
authors: Galindo
authors: N
authors: N
authors: Galanti
authors: A
authors: A
authors: Orn
authors: R
authors: R
authors: Billetta
authors: A
authors: A
authors: Ferreira
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D037282:Calreticulin; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D002135:Calcium-Binding Proteins; D037282:Calreticulin; D012261:Ribonucleoproteins