Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • C07K14/37—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from fungi
  • C07K14/39—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from fungi from yeasts
  • C07K14/40—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from fungi from yeasts from Candida
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K38/00—Medicinal preparations containing peptides

Definitions

• the invention concerns the cDNA and the corresponding protein of a heat shock protein isolated from C. albicans, and fragments thereof to develop methods to identify C. albicans in biological and/or environment samples, and/or preparations either for therapeutic, prophylaxis or vaccine purpose.
• Pathogenic yeasts are the major agents of opportunistic infections in immunosuppressed patients, in particular AIDS, tumor, neutropenia patients or bone marrow transplanted subjects (1) .
• HIV * subject susceptibility to C. albicans is related to the strong decrease of cell-mediated immunity because of the numerical and functional decrease of CD4 + helper-inducer lymphocytes (2) .
• the authors of the instant invention isolated the caRLV130 clone from an expression library in the ⁇ gtll phage obtained by cDNA isolated from C. albicans at the yeast growth stage. Said clone contains a DNA insert of 2325 base pairs which codes in the 5'-3' direction from +105 to +2072 for a 656 aminoacid protein having a strong homology with a S. cerevisiae heat shock protein 70.
• HSPs are induced by different stresses, either chemical or physical, normally by heating. Many HSPs are present and active also in non stressed cells, where they play important functions of cell physiology
• HSPs reactive oxygen species
• HSPs may be grouped in families of different molecular weights, very conserved even among phylogenesis distant organisms (5) . Therefore it should not be surprising either that HSPs are involved in the immune response, or that they represent major antigens of different pathogenic agents, or that they may give autoimmune responses, given to the fact that the infection itself represents an extreme form of stress, both for the infectious agent and for the host (4) .
• nucleic acid comprising a nucleotide sequence coding the protein having the amino acid sequence of SEQ ID No.2 or parts thereof.
• nucleic acid comprises a nucleotide sequence with at least a 65% homology with the nucleotide sequence of SEQ ID No.l or parts thereof. More preferably the nucleic acid comprises the nucleotide sequence of SEQ ID No.l or parts thereof.
• composition comprising a nucleic acid comprising a nucleotide sequence coding the protein having the amino acid sequence of SEQ ID No.l or parts thereof.
• the composition comprises a nucleic acid having a nucleotide sequence with at least a 65% homology with the nucleotide sequence of SEQ ID No.l or parts thereof. More preferably the composition comprises a nucleic acid having the nucleotide sequence of SEQ ID No.l or parts thereof.
• nucleic acid comprising a nucleotide sequence coding the protein having the amino acid sequence of SEQ ID No.2 or parts thereof for oligonucleotide probes to be used in diagnosis and typing of Candida related pathologies.
• the use of a nucleic acid having at least a 65% homology with the nucleotide sequence of SEQ ID No.l or parts thereof is preferred.
• the use of a nucleic acid having the nucleotide sequence of SEQ ID No.l or parts thereof is most preferred.
• the oligonucleotides of the invention are advantageously used for PCR (polymerase chain reaction) to detect the presence in biological and/or environment samples either of C. albicans or of other Candida species or of yeast-like related microorganisms comprising said gene; in a labeled form (radionuclides, biotin, enzymes, etc.) to detect the presence in biological and/or environment samples either of C. albicans or of other related; for the C. albicans or related species typing and/or diagnosis; as potential antibiotic and/or chemiotherapic targets, or antisense RNA active for Candida species and/or, yeast-like related microorganisms coding an homologous sequence.
• PCR polymerase chain reaction
• Another object of the invention is a polypeptide having the aminoacid sequence comprised in the SEQ ID No.2, or having at least a 50% homology with SEQ ID No. 2 or fragments, and/or functional and immunologic homologous thereof.
• composition comprising a polypeptide having an amino acid sequence comprised in SEQ ID No.2 or having at least a 50% homology with SEQ ID No. 2 or fragments, and/or functional and immunologic homologous thereof.
• HSP70 heat shock protein
• polypeptide having the amino acid sequence comprised in SEQ ID No.2 or having at least a 50% homology with SEQ ID No. 2 or of fragments, and/or functional and/or immunologic homologous thereof for the preparation of a composition to be used for prophylaxis and/or therapy of C. albicans or related microorganisms (pathogenic yeasts) diseases.
• Figure 1 represents the 1971 base pair DNA sequence (small letters) corresponding to the open reading frame of ⁇ gtll- (caRLAl30) clone insert and deduced aminoacid sequence (capital letters one-letter code) .
• Figure 2 represents the nucleotide sequence of the coding insert of caRLV130 clone (small letter) and comparison with S. cerevisiae YSCSSA1 gene (capital letter) .
• Figure 3 represents the 656 aminoacid sequence deduced from the coding insert of caRLV130 clone (small letter) and comparison with the S. cerevisiae YSCSSA1 gene (capital letter) .
• the aminoacid code utilized is the one letter code.
• Figure 4 represents in panel A. Southern blot analysis of C. albicans strain ATCC 20955 chromosomes, obtained by pulse field electrophoresis (TAFE) .
• the caRLV130 probe labeling refers to the highest molecular weight chromosome (3.5 Mbp) .
• panel B Electrophoretic separation of C. albicans strain ATCC 20955 chromosomes.
• Figure 5 represents on the left side: Northern blot analysis by hybridization of total RNA extracted from C. albicans cells grown at 22°C and transferred at 37°C for the time indicated with radiolabeled caRLV130 (cahsp70) and actin probes. The actin probe hybridization was performed to control the RNA amount on filters (see ref. 8) .
• On the right side immunoblotting reactivity of anti- CAHSP70 mouse serum with C. albicans extracts, at different times further to inducing a heat shock response as previously described.
• Figure 6 represents in panel A. SDS-PAGE analysis: a) expression products of E. coli M15 containing the pDS5 ⁇ /RBS-E " -6his caRLV130/l plas id; b) expression products of E. coli M15 containing the pDS56/RBS-E " -6his caRLV130/2 plasmid; c) expression products of E. coli M15 containing the pDS56/RBS-E " -6his caRLV130/3 plasmid; d) expression products of E. coli M15 containing the pDS56/RBS-E " -6his caRLV130/4 plasmid.
• N.I. Non induced E. coli culture extracts.
• Figure 7 represents the reactivity after immunoblotting on nitrocellulose filters of mouse sera as shown in the figure obtained against CAHSP70 fragments; a) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/l plasmid in 1 mM IPTG induced E. coli; b) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/2 plasmid in 1 mM IPTG induced M15 E. coli; c) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/3 plasmid in 1 mM IPTG induced M15 E.
• Figure 8 represents the reactivity after immunoblotting on nitrocellulose filters of wealthy human sera obtained against CAHSP70 and fragments thereof; a) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/l plasmid in 1 mM IPTG induced M15 E. coli; b) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/2 plasmid in 1 mM IPTG induced M15 E. coli; c) expression products of nickel column purified pDS56/RBSII-E " -6his caRLV130/3 plasmid in 1 mM IPTG induced M15 E.
• Figure 9 represents in panel A. PCR experiment performed using oligonucleotide combination CA2-CA3 in the presence of C. albicans, C. parapsilosis (2) , C. glabrata (3), C. guillermondii (4) , C. krusei (5), C_;_ tropicalis (6), Mus muris (7), E. coli (8), S. cerevisiae (9) DNAs. Control with no DNA is as (10). At the right side the molecular weight of the amplified fragment is indicated.
• panel B PCR experiment using the combination of CA1-CA4 oligonucleotides in the presence of C. albicans cDNA: DNA amplified from C.
• PCR reaction conditions are as follows: 90 sec. 94°C denaturation; 90 sec. 60°C annealing; 120 sec. 72°C extension; 25 cycles.
• Figure 1 shows the 1971 bp coding region of the isolated gene.
• the caRLV130 sequence was filed with EMBL data base (No. Z30210) . No intron can be found in the intronic sequence, as shown by PCR product analysis and by ⁇ Southern-blot". By comparing the caRLV130 insert sequence with sequences present in the 6.7 version "GENE BANK" data base, some homologies can be detected. The insert shows the most high homology with the S ⁇ cerevisiae gene SSAl (one of the nine heatshock yeast gene family) . The overall nucleotide sequence homology is of 78.8% in the coding region (figg. 2 and 3).
• the gene corresponding to the caRLV130 sequence was mapped on the C. albicans chromosome showing the highest molecular weight (3.5 Mpb) by pulse field electrophoresis (transverse-alternate: TAFE) utilizing the caRLV130 labeled cDNA insert as hybridization probe with C. albicans chromosomes blotted on nitrocellulose filters (fig. 4A an 4B) .
• TAFE pulse field electrophoresis
• TAFE reverse-alternate
• Gene transcription is activated by exposing cells to a temperature higher than room temperature (thermal shift from 22°C to 37°C) . Such finding was demonstrated by hybridization experiments using C.
• albicans total RNA from cells grown either at 22°C or at 37°C, fractionated according to molecular weight on formaldehyde agarose gel and blotted on nitrocellulose -filters
• the induction of transcription is coupled also to an increase of protein expression, 2, 6 and 24 hours further to the 22°C to 37°C temperature shift (see fig. 5) .
• Peptides are coded by pDS56/RBSII-E " -6his recombinant plasmids wherein caRLV130 fragments were cloned.
• the position refers to nucleotide and aminoacid sequences as shown in Fig. 1.
• the peptide length refers to the fusion product coded by the recombinant plasmid.
• recombinant peptides were used as immunogens to produce mouse immune sera and are therefore able also to induce monoclonal antibodies.
• polypeptides and the whole purified protein as well, induce specific antibodies in a 18-22 g weight
• the indicated immunogen concentration was inoculated intraperitoneally in a 200 ⁇ l volume.
• the titer was determined by indirect ELISA with the antigen used for coating at a 200 ng/well concentration, in a final volume of 100 ⁇ l, and represents the highest serum dilution able to give an ELISA positive reaction (optical density at 405 n > two fold the no antigen control value) .
• Serum titers for each antigen resulted to be > 12.800 by immunoenzyme test (indirect ELISA) with the adsorbed antigen at 200 ng/well, in a final volume of 100 ⁇ l.
• immunoenzyme test direct ELISA
• the specificity of immunoenzyme test results were confirmed in immunoblot experiments on nitrocellulose filters, as shown in Fig. 7.
• lymphoproliferative activity " " ⁇ -thymidine uptake
• cord blood 1 cord blood 2 none 2.5 ⁇ 0.4 1.3 ⁇ 0.3
• CAHSP70 the C. albicans protein having the following properties: I) it comprises the aminoacid sequence coded by the caRLV130 insert; II) its gene maps on C.
• albicans chromosome 1 (having the highest molecular weight); III) its expression is induced by temperature shift; IV) it induces specific antibodies able to recognize cloned and purified fragments (subunits) ; V) it induces a lymphoproliferation in lymphomonocytic cultures from peripheral human blood.
• the relevant gene was named as cahsp70.
• CAHSP70 cloning allows to develop a diagnostic molecular method based upon the amplification of DNA inserts corresponding to caRLV130, other than immunological studies of C. albicans 70 kDa heat shock protein expression.
• caRLV130 insert sequence we have synthesized oligonucleotides which were utilized for polymerase chain reaction (PCR) experiments, to analyze their ability to amplify DNA fragments which are homologous to C. albicans caRLV130 DNA.
• PCR polymerase chain reaction
• Two oligonucleotides were chosen in the regions showing the minimal homology between the caRLV130 cDNA sequence and known HSP70 coding gene sequences (see Fig.
• GGT AAA CCA GTG ATT CAA GTT GAA TAT AAA GGT GAA ACT AAA ACT TTT 336 Gly Lys Pro Val He Gin Val Glu Tyr Lys Gly Glu Thr Lys Thr Phe 100 105 110
• GGT GGG TCC ACC AGA ATT CCA AAG ATT CAA AAA TTG GTT TCT GAT TTC 1056
• MOLECULE TYPE protein

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• 1995
  • 1995-05-16 IT IT95RM000314A patent/IT1282287B1/it active IP Right Grant
• 1996
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