|Title of Invention||
"ANTICARCINOMA ANTIBODIES AND USES THEREOF"
|Abstract||The present invention essentially relates to an isolated antibody or antibody fragment comprising a complementarity determining region 1 (CDR1) sequence KNLMG; a CDR2 sequence TISGSGGTNYASSVEG; and a CDR3 sequence AFAI, wherein the isolated antibody or antibody fragment binds to non-small cell lung carcinoma.|
It is widely expected that proteomic research will greatly facilitate the discovery of novel tumor targets. Major advances have been made in the identification of targets for diagnostic purposes. However, limitations of the present technologies have hindered identification of new therapeutic targets. The techniques commonly employed in proteomics, such as two-dimensional gel electrophoresis, Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS), Matrix-Assisted Laser Desorption lonization/Mass Spectrometry (MALDI-MS), and the yeast two-hybrid system have not met the demand for "drugable" targets, such as cell surface markers.
Tumor targeting antibodies and peptides can be isolated by library display approaches (e.g. Aina, 2002; Hoogenboom, 1998). This is usually accomplished by screening a phage display library, or libraries with other display formats, against purified tumor specific or tumor associated antigens. However, tumor targeting antibodies and peptides have also been isolated by panning libraries against tumor cells or tumor tissues without prior information on "the molecular targets. Noteworthy advantages of the latter approach are: (i) the isolated antibodies/peptides bind to native forms of their antigens/ligands on the cell surface whereas purified tumor antigens are often recombinant in nature and lack post-translational modification, (ii) the antigens are accessible to the isolated antibodies/peptides whereas those isolated by panning against pure antigens may recognize epitopes which are naturally buried in the membrane or blocked by carbohydrate modification. However, antibodies/peptides isolated with this method usually have a low to moderate affinity to their antigens/ligands.
Since each M13 phage particle presents five copies of the minor coat protein pill, a phage particle displaying an antibody fragment on all copies of pill can be considered a pentavalent antibody. This multivalent display of antibody fragments on phage greatly increases the avidity of the antibody and facilitates both screening and evaluation of phage antibodies. Isolated
antibody fragments (scFvs or sdAbs) or peptides bind antigen much less efficiently since they exist primarily in a monovalent form and lack avidity.
An antibody fragment oligomerization strategy that permits pentavalency as in pill phage display is the subject of PCT/CA02/01829 (MacKenzie and Zhang). Fusion of a single domain antibody (sdAb) to the homo-pentamerization domain of the B subunit of verotoxin (VT1 B) results in the simultaneous pentamerization of the sdAb. The pentavalent sdAbs, termed pentabodies, bind much more strongly to immobilized antigen than their monomeric counterparts. In the instance of peptide hormone-binding sdAb, pentamerization resulted in 103 to 104-fold improvement in binding to immobilized antigen.
It is an object of the invention to provide a single-domain antibody with affinity for lung carcinoma.
SUMMARY OF THE INVENTION
There is provided herein a novel single domain antibody and fragments thereof which has specific affinity for binding to carcinoma, and especially lung carcinoma. This antibody, and portions thereof, can be used, inter alia in the diagnosis and treatment of carcinoma.
BRIEF DESCRIPTION OF THE FIGURES
FIGURE 1 is a depiction of monomeric and pentameric AFAI antibody, (a) Sequence of AFAI antibody (SEQ ID NO. 1) with CDR1, CDR2 and CDR3 underlined; (b) Schematic of the primary structures of the monomeric (AFAI antibody) and pentameric (ES1) proteins; (c) sequence of ES1 (SEQ ID NO. .2) with the sequence of AFAI monomer underlined; (d) SDS-PAGE of purified ES1 (lane 1) and AFAI antibody (lane 2).
FIGURE 2 is a pictorial depiction of immunocytochemical staining of A549 cells with the AFAI phage antibody. Cells were exposed to the AFAI phage antibody as the first antibody, mouse anti-M13 IgG as the second antibody and Alexa Fluor 546 labeled goat anti-mouse IgG as the third antibody. DAPI and DiOC5(3) were used to stain cell nuclei and endoplasmic reticulum, respectively.
FIGURE 3 is a pictorial depiction of immunocytochemical staining of A549 with AFAI antibody and ES1. A549 cells were exposed to either ES1 (A) or AFAI antibody (D) as the first antibody, monoclonal anti-c-myc IgG as the second antibody, Alexa Fluor 546 (red) labeled anti-mouse IgG as the third antibody. DAPI staining of (A) and (D) are shown in (B) and (E), respectively. Superimpositions of A, B and D, E are shown in C and F, respectively.
FIGURE 4 is a pictorial depiction of immunohistochemical staining showing that ES1 binds strongly to differentiated lung adenocarcinoma and does not bind to most colon adenocarcinomas or to normal lung tissue. (A) Strong positive staining of a lung adenocarcinoma, (B) enlarged view of the boxed area in (A), (C) negative staining of a colon adenocarcinoma and (D) negative staining of normal lung tissue.
FIGURE 5 is a depiction of bronchiolo-alveolar carcinoma of mucinous 1ype: (A) Immunostaining for ES1 showing diffuse moderate immunoreactivity, mainly along luminal borders; (B) A high magnification of an area in A; (C) Immunostaining for TTF1 (DAKO) showing negative immunoreactivity.
FIGURE 6 is a depiction of metastatic poorly differentiated lung adenocarcinoma: (A) Immunostaining for ES1 showing diffuse strong immunoreactivity; (B) A high magnification of an area in A; (C) Immunostaining forTTFI showing negative immunoreactivity.
FIGURE 7 is a depiction of Lung moderately differentiated adenocarcinoma: (A) Immunostaining for ES1 showing strong immunoreactivity in a focal area adjacent to an area displaying focal weak staining; (B) A high magnification of an area in A; (C) Immunostaining for MIB1 (DAKO) showing remarkable increase in immunoreactivity in an area with strong ES1 immunoreactivity.
FIGURE 8 is a depiction of lung poorly differentiated adenocarcinoma: (A) Immunostaining for ES1 showing moderate and extensive immunoreactivity; (B, C) High magnification of area in A. Note the negative immunostaining in the normal bronchial epithelium.
FIGURE 9 is a depiction of lung Adeno-squamous carcinoma: (A) Immunostaining for ES1 showing focal immunoreactivity; (B, C) High magnifications of an area in A showing focal immunoreactivity.
FIGURE 10 is a depiction of a typical adenomatous hyperplasia of the lung: (A) Immunostaining for ES1 showing focal weak immunoreactivity, (B, C) High magnifications of an area in A showing weak immunoreactivity.
FIGURE 11 is a depiction of metastatic moderately differentiated colonic adenocarcinoma in the brain: (A) Immunostaining for ES1 showing focal immunoreactivity in a few single cells; (B) A high magnification of an area in A.
FIGURE 12 is a depiction of infiltrating duct carcinoma of the breast: (A) Immunostaining for ES1 showing focal moderate immunoreactivity; (B) A high magnification of an area in A; (C) Focal strong immunoreactivity in a few acini in normal breast tissue.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Proteomics research has delivered many novel tumor targets. However, due to some limitations, it has been difficult to identify targets that are most accessible for drug application. A novel tumor antigen discovery platform based on screening a single domain antibody (sdAb) library against tumor cells and subsequently identifying the corresponding antigens of the isolated antibodies is described herein. A specific sdAb, AFAI antibody, specific for non-small cell lung carcinoma (A549 cell line) was isolated from a phage library derived from the heavy chain antibody repertoire of a llama as
described in Example 1. The homopentamerization property of a non-toxic verotoxin B-subunit was exploited to make the ES1 pentabody, the pentameric forms of AFAI antibody. Pentamerization dramatically improved the binding of the AFAI antibody to A549 cells. Immunohistostaining showed that ES1 is highly specific for lung carcinoma.
It is possible in light of the disclosure herein to chemically synthesize the whole gene for ES1 and express it in E.coli or another suitable organism according to standard techniques. The gene of AFAI antibody can be synthesized from ES1, which is the binding entity to its antigen. It is possible, in light of the disclosure herein, to make dimeric, trimeric, tetrameric, other pentameric and other multivalent forms of AFAI antibody. Such products can be useful in methods and compositions relating to the present invention, as can DNA and clone material providing variants of such products which provide specific binding to a malignant tissue or cells of interest, as described herein.
ES1, AFAI antibody and/or variants thereof showing similar binding specificity ("suitable variants") are useful in the diagnosis and treatment of lung carcinoma. Diagnostic methods with which ES1, AFAI antibody and/or suitable variants thereof can be used include: immunohistochemical methods; labeling the molecule(s) (ES1, AFAI antibody, variants) with radio isotopes and detecting with tumor imaging tools such as positron emission tomography and MRI; analysis of blood samples (and detecting binding using standard techniques).
Diagnostic kits comprising ES1, AFAI antibody and/or a suitable variant thereof and instructions for their use are specifically contemplated.
Therapeutic methods and compositions relating to ES1 and AFAI antibody include employing AFAI antibody, ES1, or a suitable variant thereof and, for example: labeling them with radio isotope and applying the molecules to a patient; conjugating them to one or more conventional therapeutics and applying the conjugate to a patient; conjugating them to one or more toxins and applying the conjugates to patients; expressing nucleic acid molecules encoding ES1, AFAI antibody and/or a suitable variant thereof in a gene therapy vector and applying the vectors to patients.
Results Example 1: Cell culture
The non-small cell lung carcinoma cell line A549 was purchased from ATCC (Manassas, VA) and maintained in DMEM (Gibco, Rockville, MA) supplemented with 5% FBS (Gibco) and 1% Antibiotic-Antimycotic (Gibco). Primary human dermal fibroblast cells were kindly provided by Dr. J. Xu (Apotex Research Inc. Ottawa, ON). Polyclonal rabbit anti-verotoxin antiserum was kindly provided by Dr. Clifford Lingwood (Univ. of Toronto).
Isolation of sdAb AFAI which binds to non-small cell lung carcinoma cell line A549
A naive llama single domain antibody library (Tanha et al, 2002) served as the source of an antibody fragment specific for tumor cells, in this instance the non-small cell lung carcinoma cell line A549. The isolation of phage antibodies that bind to A549 cells, termed cell panning, was performed with A549 cells with pre-adsorption of the library on human fibroblasts at each round of panning.
An sdAb phage display library (Tanha et al, 2002) was panned with A549 as the target cells and human dermal fibroblasts as subtracting cells. The panning was performed as described in Becerril et. al. (1999) with slight modifications. For the first round of panning, 1013 pfu were incubated with the subtracting fibroblast cells to remove fibroblast-binding phage. Phage particles remaining in the supernatant were incubated with A549 cells cultured in a 5 cm petri dish at room temperature for 1 hr. The A549 cells were washed 5 times, 1 minute each, with PBS and 5 times, 10 minutes each, with stripping buffer (50 mM glycine, pH 2.8, 0.5 M NaCI, 2 M urea, 2% polyvinylpyrolidone) and then lysed with 100 mM triethylamine. The cell lysate was neutralized by the addition of 100 pi of 1 M Tris (pH 7.0). Phage in the neutralized cell lysate were amplified in E. coli TG1 cells. The amplified sub-library was subjected to the next round of panning employing the same method. Individual phage clones were selected after four rounds of panning and the DNA sequences encoding the displayed antibodies were determined.
Individual phage clones were isolated after four rounds of panning and the cell binding activities of the phage clones were examined by ELISA. Of 94 clones, 25 clones tested positive. Sequence analysis of the ELISA-positive phage clones showed that all 25 positive phage clones displayed the same sdAb. This antibody was designated AFAI antibody because the CDR3 region of the antibody is the tetrapeptide Ala-Phe-Ala-lle (Figure 1).
Cell Staining Part A: Cell staining with phage displayed AFAI antibody
When A549 cells were immunostained with AFAI phage antibody as the first antibody followed by an anti-M13 monoclonal antibody and Fluor 546 labeled goat anti-mouse IgG, it was observed that very intense fluorescent signals were associated with a cell sub-population (Fig. 2). The staining pattern of the positive A549 cells suggested that AFAI antibody binds to an abundant membrane antigen.
To investigate whether the binding of AFAI phage antibody to A549 cells is cell type specific, a human bronchial epithelial cell line, HBE4, a human prostate cell line, PREP and a primary human fibroblast cell line were chosen as controls for immunocytochemical staining. Under the same conditions employed for A549 immunocytochemistry, no staining was observed with human fibroblasts and only very weak staining was observed with HBE4 and PREP.
Cell Staining Part B: Production of monomeric and pentameric AFAI sdAbs and cell staining with the sdAbs
For further evaluation and characterization of AFAI antibody, monomeric and pentameric AFAI antibody were expressed and purified. The gene encoding AFAI antibody was amplified by PCR and inserted into an E. coli expression vector, generating clone pAFAl (Fig. 1B). To exploit the high avidity effect of pentabodies, a pentameric form of AFAI antibody, designated ES1, was constructed (Fig. 1B and Fig.
1C). The yields of purified AFAI antibody and ES1 (Fig. 1D) from 1 liter flask cultures of E. coli TG1, without fermentation optimization, were 6 mg and 20 mg, respectively.
Briefly, DNA encoding AFAI sdAb was cloned into the Bbsl/BamHI sites of plasmid pSJF2 (Tanha, 2003) and Bbsl/Apal sites of plasmid pVT2 to generate expression vectors for monomeric and pentavalent AFAI antibody, respectively. The obtained E.coli clones were designated pAFAl (monomer) and pES1 (pentamer). AFAI antibody and ES1 were produced as described in Tanha et. al. (2003) with the modification of protein extraction from E.coli cells by cell lysis instead of osmotic shock. Briefly, the pAFAl and pES1 clones were inoculated into 100 ml M9 medium (0.2% glucose, 0.6% Na2HP04, 0.3% KH2P04, 0.1% NH4CI, 0.05% NaCI, 1 mM MgCI2, 0.1 mM CaCI2) supplemented with 0,4% casamino acids, 5 mg/l vitamin B1 and 200 ug/ml ampiciliin and shaken overnight at 37 °C. Thirty ml of the overnight M9 culture were transferred into 1 liter of M9 medium with the same supplements and shaken at 37 °C for 24 hours. Induction of gene expression was initiated by the addition of 100 ml 10 xTB nutrients (12% Tryptone, 24% yeast extract, 4% glycerol), .2 ml of 100 mg/ml ampiciliin and 1 ml of 1 M IPTG and the cultures were shaken at room temperature for 48 to 72 hours. E. coli cells were harvested by centrifugation and lysed with an Emulsiflex™ Cell Disruptor (Avestin Inc. Ottawa, ON). The cell lysate was centrifuged, the obtained clear supernatant was loaded onto a Hi-Trap™ Chelating Affinity Column (Amersham Biosciences, Piscataway, NJ) and proteins containing Hiss tag were purified following the manufacturer's instructions.
Immunochemical staining of A549 cells was performed with both monomeric (AFAI antibody) and pentameric (ES1) antibodies.
Standard immunochemical methods, with slight modifications, were employed in cell staining with AFAI phage antibody and with monomeric and pentameric AFAI antibody. Cells were grown on slide cover slips to approximately 70% confluence and fixed for 10 minutes with 4% formaldehyde in PBS. Permeabilization was carried out for 30 minutes at room temperature in 0.05% NP-40 (Bio-Rad, Hercules, CA) followed by three washes with PBS containing 0.05% Tween-20 (PBST). For cell staining with AFAI phage, 2 x 1011 pfu of
AFAI phage (in A549 medium) were incubated with fixed cells for 18 hours at 4 °C and washed three times, 5 minutes each, with PBST. For cell staining with monomeric or pentameric AFAI antibody, 100 ug/ml of AFAI antibody and ES1 (in A549 medium) were incubated with the cells for 2 hours at room temperature and washed three times with PBST. Secondary antibodies, monoclonal anti-M13 IgG (Amersham Biosciences) for M13 phage or the 9E10 anti c-myc IgG (ATCC) for the ES1 pentabody were applied at a 1:100 dilution for 30 minutes at room temperature followed by three washes with PBST. The third antibody, Alexa Fluor 546-labeled goat anti-mouse IgG™ (Molecular Probes, Inc. Eugene, OR), was diluted 1:100 and applied in the same way as the secondary antibodies. Contrast staining was performed with DAPI and (DiOC5)3 (Molecular Probes). Following immunochemical staining cover slips were mounted using an Prolong Antifade Kit (Molecular Probes) and observed under an Olympus BX51™ fluorescent microscope and images were recorded.
No obvious staining was observed when AFAI antibody was employed (Fig. 3), probably because of the low binding affinity of monomeric AFAI antibody. The ability of AFAI antibody to stain A549 cells was, however, observed when the pentameric form, ES1, was employed (Fig. 3). As observed with AFAI phage antibody, ES1 stains only a sub-population of A549 cells.
Determination of specificity of ES1 to tumor tissues
To determine the tissue specificity of ES1, immunohistochemical staining of a broad range of tissues on a tissue microarray using ES1 as primary antibody was performed. The results showed that ES1 recognized most lung adenocarcinomas by displaying a moderate to strong immunoreactivity. None of colon adenocarcinoma displayed strong immunoreactivity for ES1 however a focal weak to moderate immunoreactivity was observed in a few cases. Non cancerous lung and colon tissues were not immunoreactive (Fig. 4, Table 1).
To determine the tissue specificity of ES1, immunohistochemical staining of a broad range of tissues was performed using ES1 as primary antibody.
Immunostaining of human tissues using ES1 as the primary antibody was performed using the avidin-biotin peroxidase complex (ABC) method with an ABC kit (Vector Laboratories, Burlingame, CA, USA) on four micron-thick sections cut from the paraffin blocks.
Immunostaining of human tissues using MIB1 (Dako, dilution 1:100) and TTF1(Dako, dilution 1:50), two broadly used antibodies in lung carcinoma detection was performed using peroxidase-antiperoxidase technique.
The immunoreactivity for ES1 was assessed by two pathologists and was scored as moderately or strongly positive staining when there was a continuous membranous and/or cytoplasmic staining pattern and as weakly positive when there was discontinuous membrane or weak cytoplasmic staining. The moderate or strong staining pattern was further scored as 3 in cases showing staining in more than 50%, 2 in more than 10% and 1 in up to 10% of cells. Cases with a discrepant score were reviewed.
One hundred-forty three resection or biopsy specimens containing tumors of lung, colon, breast, stomach, pancreas, prostate, endometrium, ovary, thyroid and mesothelium were obtained (Table 1). For each case, one sample of representative tumor tissue, 2 mm in diameter, was removed from the paraffin block and re-embedded with other tumor samples to produce a tissue micro array paraffin block that contained at least 15 different tissues. Normal tissue was also sampled from non tumoral tissue distant from the tumor and from the normal autopsy lung tissue. Cases of lung, colon, breast, stomach, pancreas, urinary bladder, gall bladder, esophagus and ovary with microarray tissue displaying negative, weak or focal immunoreactivity were re-submitted for immunostaining for ES1 using large tissue sections.
Table 2 compares the immunostaining results of the group of non-squamous large cell lung carcinomas with the combined group of colonic, mammary, urothelial carcinomas and other mucus-secreting adenocarcinomas. Excluding other types of carcinomas which showed weak or negative ES1 immunoreactivity, the sensitivity and the specificity of ES1 immunoreactivity for lung non-squamous large cell carcinomas were 97 and 45% respectively. The positive predictive value was 54%. The results showed that ES1 displayed moderate to strong immunoreactivity with most lung adenocarcinomas. None of the colon adenocarcinomas displayed strong immunoreactivity with ES1; however, weak to moderate focal immunoreactivity was observed in a few cases. Non cancerous lung and colon tissues were not immunoreactive. The reactivity was often stronger on the membrane (Figures 5,6,7) than in the cytoplasm (Figure 8). The pattern of positive immunostaining varied from diffuse (Figures 5,6) to focal staining in portions of tumor or individual cells (Figures 7,8). Of 93 cases with negative, weak or focal immunoreactivity in microarray sections, there were eleven large sections showing a score of 1 or 2 immunoreactivity. Table 1 summarizes the final findings on immunostaining of all specimens.
Thirty-five non-squamous large cell carcinomas of the lung including seven bronchiolo-alveoiar carcinomas and 22 well to poorly-differentiated adenocarcinomas, six large cell undifferentiated carcinomas showed scores of 1, 2 and 3 immunoreactivity in 7, 17 and 10 tumors respectively (Figures 5 to 8). The remaining carcinoma was an undifferentiated large cell carcinoma with some features of squamous differentiation showing negative immunoreactivity. The tumors with focal moderate to strong immunoreactivity (less than 10% immunoreactive cells) were well-differentiated non-mucinous tumors. Two adeno-squamous carcinomas also displayed scores of 1 and 2 immunoreactivity in the adenocarcinoma component (Figure 9). Four of five atypical adenomatous hyperplasias of the lung showed focal or weak immunoreactivity (Figure 10). All pure squamous carcinomas, carcinoid tumors, normal and reactive lung parenchyma with or without accompanying carcinomas were not reactive for the antibody.
For 53 non-lung and mucus-secreting tumor including 15 adenocarcinoma colonic adenocarcinomas, 8 breast carcinomas, 4 urothelial carcinomas and adenocarcinomas of the pancreas (six), stomach (six) and gallbladder (one), esophagus (three), urinary bladder (two), ovary (three) and trachea (one), the immunoreactivity was scored as 1, 2 , 3, weak and negative in 15, 11, 3, 12 and 12, respectively (Figures 11,12). Colonic adenocarcinomas formed the subgroup of tumor with more diffuse and strong immunoreactivity. Colonic adenomas only displayed focal or weak immunoreactivity.
For 32 non lung and non-mucinous tumors, the immunoreactivity was negative or weak. Normal tissues from lung, liver, pancreas, kidney, urinary bladder, endometrium, thyroid, esophagus and ovary from areas surrounding cancer or from organs not harboring cancer were not reactive for cancer with exception of one case of breast tissue (surrounding duct carcinoma) showing moderate positivity in occasional acini. Immunostaining for MIB1 performed on 24 large sections of 24 non-squamous large cell lung carcinomas with score 1 or 2 immunoreactivity showed a remarkable increase in proliferativity of tumor cells in areas of large numbers of ES1-immunoreactive cells as compared to areas with negative, weak or focal ES1-immunoreactive cells. The immunostaining for TTF1 was performed on microarray tissue. All non-lung and non-thyroid tissue showed negative nuclear immunoreactivity. For 35 lung non-squamous large cell carcinomas, TTF1 immunoreactivity was negative in 8 cases including 5 undifferentiated large cell carcinomas, two poorly-differentiated adenocarcinomas and one mucinous bronchiolo-alveolar carcinoma. The other types of microarray tissue were not immunoreactive.
In this study, ES1 immunoreactivity was almost completely limited to malignant tumors, particularly lung adenocarcinomas. There was a tendency for the immunoreactivity to be stronger in lung tumors with a mucinous component as non-mucinous bronchiolo-alveolar carcinomas showed only focal immunoreactivity. ES1 immunoreactivity was positive in a number of colonic adenocarcinomas with weaker and more focal staining than in lung
adenocarcinomas. Of interest, ES1 immunostaining remained scoring 2 or 3 for undifferentiated large cell lung carcinoma in the primary as well as in the metastatic sites as compared to low sensitivity of TTF1 in the immunostaining of the undifferentiated large cell lung carcinoma (*). Furthermore colonic adenomas showed only focal weak or negative immunoreactivity. Mucinous adenocarcinoma from other organs displayed score 2, focal or weak immunoreactivity in a small number of cases. The immunoreactive changes identified in the lung adenocarcinomas in this study likely correspond to an up-regulation of the AFAI antibody's antigen. This impression is supported by the finding of positive ES1 immunoreactivity in areas of carcinoma of the lung with increased proliferativity as demonstrated by the immunoreactivity for MIB1.
Non-limiting discussion of variations and uses of AFAI antibody
The AFAI antibody's antigen, appears to be up-regulated in lung adenocarcinoma, even in less differentiated tumors. ES1 is likely a more sensitive marker for lung poorly differentiated lung adenocarcinoma than TTF1. Since most normal tissue tested were not ES1-immunoreactive, ES1 is suitable for use in the development of a screening test for lung adenocarcinomas and a number of colon and breast carcinomas.
In an embodiment of the invention there is provided an amino acid sequence of AFAI antibody as shown in Figure 1 or an amino acid sequence at least 90%, 95% or 98% identical to it. Examples of variant amino acid sequences of interest are shown in Table III in which unchanged residues are indicated by a hyphen. It will be appreciated that AFAI antibody may be mutated at any position which does not interfere with antigen binding or specificity. Sites of particular interest include those for which some possible mutations are shown in Table III. While only some possible variants are shown, it will be appreciated that all functional variants, including all variants of AFAI antibody differing from SEQ. ID. No. 1 by one or more of the amino acid changes depicted in Table III are specifically contemplated and fall within the scope of the invention.
ln an embodiment of the invention there is provided an amino acid sequence having complete sequence identity to the underlined (CDR) regions of AFAI antibody as shown in Figure 1 and having at least 40%, 60%, 80%, or 90% sequence identity to the remaining portions of that sequence. Also provided are nucleic acid sequences encoding such amino acid sequences.
In an embodiment of the invention there is provided nucleic acid sequences encoding AFAI antibody as disclosed in Figure 1, or an amino acid sequence at least 90% or 95% identical to it. In an embodiment of the invention there is provided a nucleic acid sequence encoding a protein which has at least 70%, 80%, 90%, 95%, or 98% sequence identity to the sequence of AFAI antibody or ES1 as depicted in Table 2, or to a continuous 250 nucleic acid region thereof, or being complementary to any such nucleic acid sequence. In an embodiment of the invention there are provided PCR primers suitable for the amplification of a nucleic acid encoding AFAI antibody or a portion thereof. In some instances the portion will include at least one CDR region.
In an embodiment of the invention there is provided a polypeptide sequence comprising at least 90 amino acids including at least one of the following three contiguous amino acid sequences: KNLMG, TISGSGGTNYASSVEG, and AFAI.
In an embodiment of the invention there is provided the use of an AFAI antibody-derived polypeptide and/or a polypeptide having at least 90% identity to SEQ ID NO. 1 and/or a portion thereof in forming a conjugate by grafting the polypeptide to an antigen binding fragment. In some instances one or more of the AFAI antibody CDR's is grafted onto an antigen binding fragment including, for example, a VHH, VH or VL framework (scaffold) or an immunoglobin and/or fragment thereof (e.g. Fab, scFv). One or more AFAI antibody CDR's may also be used to produce a fusion protein wherein the second polypeptide sequence provides a useful functionality or property. In some instances it may be desired to produce humanized variants of the AFAI antibody using techniques known in the art. Such humanized antibodies are specifically contemplated herein. In some instances it will be desired to conjugate AFAI antibody or a portion thereof to self assembly molecules to allow for the formation of multimeric complexes having enhanced antigen-binding properties.
In an embodiment of the invention there is provided a conjugate of a polypeptide containing at least one of the three contiguous amino acid sequences and a cargo molecule or molecules. The cargo molecule may be useful for diagnosis or treatment of carcinoma. For example, it may be an enzyme or radioisotope useful in the identification and localization of cells of interest in tissue or it may be a cytotoxic agent such as a drug, further strong antigen, apoptosis inducer or radioisotope useful in reducing the viability or ability to proliferate of a carcinoma cell.
The inclusion of a reference is not an admission or suggestion that it is relevant to the patentability of anything disclosed herein.
1. Aina, O. H., Sroka, T. C, Chen, M. L. & Lam, K. S. (2002). Therapeutic cancer targeting peptides. Biopolymers 66, 184-199.
2. Hoogenboom, H. R., Henderikx, P. & de Haard, H. (1998). Creating and engineering human antibodies for immunotherapy. Adv. Drug Deliv. Rev. 31, 5-31.
3. Zhang, J., Spring, H. & Schwab, M. (2001). Neuroblastoma tumor cellbinding peptides identified through random peptide phage display. Cancer Left. 171, 153-164.
4. Tanha, J., Dubuc, G., Hirama, T., Narang, S. A. & MacKenzie, C. R. (2002). Selection by phage display of llama conventional V(H) fragments with heavy chain antibody V(H)H properties. J. Immunol. Methods 263, 97-109.
5. Williams, L. E., Wu, A. M., Yazaki, P. J., Liu, A., Raubitschek, A. A., Shively, J. E. & Wong, J. Y. (2001). Numerical selection of optimal tumor imaging agents with application to engineered antibodies. Cancer Biother. Radiopharm. 16, 25-35.
6. Rader, C, Cheresh, D. A. & Barbas, C. F., II! (1998). A phage display approach for rapid antibody humanization: designed combinatorial V gene libraries. Proc. Natl. Acad. Sci. U. S. A 95, 8910-8915.
7. Becerril, B., Poul, M. A. & Marks, J. D. (1999). Toward selection of internalizing antibodies from phage libraries. Biochem. Biophys. Res. Commun. .255, 386-393.
8. Tanha, J., Muruganandam, A. & Stanimirovic, D. (2003). Phage display technology for identifying specific antigens on brain endothelial cells. Methods Mol. Med. 89, 436-449.
9. Gharahdaghi, F., Weinberg, C. R., Meagher, D. A., Imai, B. S. & Mische, S. M. (1999). Mass spectrometric identification of proteins from silver-stained polyacrylamide gel: a method for the removal of silver ions to enhance sensitivity. Electrophoresis 20, 601-605.
10. MacKenzie R and Zhang J (2002), PCT/CA02/01829.
11. Conrath KE, Wernery U, Muyldermans S, Nguyen VK. (2003) Emergence and evolution of functional heavy-chain antibodies in Camelidae. Dev Comp Immunol. 27(2):87-103.
12. Riechmann L, Muyldermans S. (1999) Single domain antibodies: comparison of camel VH and camelised human VH domains. J Immunol Methods. 231:25-38.
13. Tanha J, Dubuc G, Hirama T,.Narang SA, MacKenzie CR. (2002) Selection by phage display of llama conventional V(H) fragments with heavy chain antibody V(H)H properties. J Immunol Methods. 263:97-109.
14. Conrath K, Lauwereys M, Wyns L, Muyidermans S. (2001) Camel single-domain antibodies as modular building units in bispecific and bivalent antibody constructs. J Biol Chem. 276(10):7346-50.
15. Muyidermans S. (2001) Single domain camel antibodies: current status. J Biotechnbl. 74(4):277-302.
Table 1: 143 neoplastic lesions and 103 samples of non-neoplastic different tissue
(Table Removed) Table 2: Comparison Between Non-Squamous Large Cell Lung Carcinomas And
1. An isolated antibody or antibody fragment comprising:
a complementarity determining region 1 (CDR1) sequence KNLMG;
a CDR2 sequence TISGSGGTNYASSVEG; and
a CDR3 sequence AFAI,
wherein the isolated antibody or antibody fragment binds to non-small cell lung
2. The isolated antibody or antibody fragment as claimed in claim 1, wherein there
is a gap of 12 to 16 amino acids between CDR1 and CDR2, 30 to 34 amino acids
between CDR2 and CDR3, and 46 to 66 amino acids between CDR1 and CDR3.
3. The isolated antibody or antibody fragment as claimed in claim 1 or 2,
comprising the sequence:
DVQLQASGGGX1VQPGGSLRLSCAAHDPIFDKNLMGWX2RQAPGKX3X4EX5V ATISGSGGTNYASSVEGRFTISRDNAKKTVYLQMNDLKPEDTAVYYCNSAFAIX6 GQGTQVTVSS,
wherein X1 is: V, S, D, L, F, W, or,T; X2 is: G, F, Y, V, I, H, or L; X3 is: Q, G, E, D, L, R, or K; X4 is: R, C, Q, L, I, P, or K; X5 is: Y, T, A, W, F, S, or L; X6 is: W, R, E, A, G, V, or K.
4. The isolated antibody or antibody fragment as claimed in any one of claims 1 to 3, wherein the antibody or fragment thereof comprises SEQ ID NO. 1.
5. The isolated antibody or antibody fragment as claimed in any one of claims 1 to 3, wherein the antibody or fragment thereof comprises SEQ ID NO.2.
6. The isolated antibody or antibody fragment as claimed in any one of claims 1 to 5, wherein the antibody or fragment thereof is a single-domain antibody.
7. The isolated antibody or antibody fragment as claimed in any one of claims 1 to 5, for targeting at least one cargo substance or cargo molecule to a lung carcinoma cell.
8. A conjugate comprising the antibody as claimed in any one of claims 1 to 5 and a cargo substance or a cargo molecule.
9. The conjugate as claimed in claim 8, for the diagnosis of lung carcinoma in mammalian tissue.
10. The conjugate as claimed in claim 8, for the treatment of lung carcinoma by reducing viability or proliferative ability of lung carcinoma cells in a mammalian subject.
11. The conjugate as claimed in claim 10, wherein the cargo substance or cargo molecule is at least one of:
one or more of an enzyme, a radioisotope or a fluorescent label useful in an identification or a localisation of lung carcinoma cells; and one or more of a cytotoxic agent such as a drug, a toxin, a further strong antigen, an apoptosis inducer or a radioisotope useful in reducing a viability or an ability to proliferate of lung carcinoma cells.
12. A kit for diagnosis or treatment of lung carcinoma cells in mammalian tissue
an antibody as claimed in any one of claims 1 to 5; and
at least one cargo substance or cargo molecule,
wherein the antibody is conjugated to at least one of the cargo substance and the
cargo molecule, and then the antibody applied to mammalian tissue.
13. The kit as claimed in claim 12, wherein the cargo substance or cargo molecule
is at least one of:
one or more of an enzyme, a radioisotope or a fluorescent label useful in an identification or a localisation of lung carcinoma cells; and
one or more of a cytotoxic agent such as a drug, a toxin, a further strong antigen, an apoptosis inducer or a radioisotope useful in reducing a viability or an ability to proliferate of lung carcinoma cells.
14. A kit for immune-staining of lung carcinoma cells in mammalian tissue
a first antibody or fragment as claimed in any one of claims 1 to 5; a second antibody; and
a label conjugated to the second antibody, wherein the second antibody is selected to be anti- to at least a portion of the first antibody; and the first antibody and the second antibody are for application to mammalian tissue for immune-staining with the label.
15. An oligomer, wherein one or more than one subunit thereof comprises the isolated antibody or antibody fragment as claimed in any one of claims 1 to 5.
16. The oligomer as claimed in claim 15, wherein subunits are linked using at least one of a peptide linker, a self assembly molecule oligomerization domain, and a chemical coupling.
17. The oligomer as claimed in claim 16, wherein the self assembly molecule oligomerization domain is a verotoxin B subunit.
18. The oligomer as claimed in any one of claims 15 to 17, comprising at least two different subunits.
19. The oligomer as claimed in any one of claims 15 to 17, comprising at least two identical subunits.
20. The oligomer as claimed in any one of claims 15 to 19, wherein at least one subunit is an antibody having a different specificity than SEQ ID NO.1.
21. The oligomer as claimed in any one of claims 15 to 19, wherein at least one subunit has an enzymatic function.
22. The oligomer as claimed in any one of claims 15 to 21, wherein at least one subunit further comprises at least one cargo substance or cargo molecule.
23. The oligomer as claimed in claim 22, wherein the cargo substance or cargo molecule is at least one of:
one or more of an enzyme, a radioisotope or a fluorescent label useful in an identification or a localisation of lung carcinoma cells; and one or more of a cytotoxic agent such as a drug, a toxin, a further strong antigen, an apoptosis inducer or a radioisotope useful in reducing a viability or an ability to proliferate of lung carcinoma cells.
24. The antibody or antibody fragment as claimed in any one of claims 1 to 4 for identifying lung carcinoma-specific antigens.
25. A nucleotide sequence encoding the antibody or antibody fragment as claimed in any one of claims 1 to 5.
26. A gene therapy vector comprising the nucleotide sequence as claimed in claim 25.
|Indian Patent Application Number||3437/DELNP/2006|
|PG Journal Number||19/2013|
|Date of Filing||14-Jun-2006|
|Name of Patentee||NATIONAL RESEARCH COUNCIL OF CANADA|
|Applicant Address||1200 MONTREAL ROAD, BLDG., M-58, ROOM EG-12, OTTAWA, ONTARIO K1A 0R6, CANADA.|
|PCT International Classification Number||C12N 15/13|
|PCT International Application Number||PCT/CA2004/001488|
|PCT International Filing date||2004-08-17|