95 results about "Affinity maturation" patented technology

The present invention provides a structure-based methodology for efficiently generating and screening protein libraries for optimized proteins with desirable biological functions, such as antibodies with high binding affinity and low immunogenicity in humans. In one embodiment, a method is provided for constructing a library of antibody sequences based on a three dimensional structure of a lead antibody. The method comprises: providing an amino acid sequence of the variable region of the heavy chain (VH) or light chain (VL) of a lead antibody, the lead antibody having a known three dimensional structure which is defined as a lead structural template; identifying the amino acid sequences in the CDRs of the lead antibody; selecting one of the CDRs in the VH or VL region of the lead antibody; providing an amino acid sequence that comprises at least 3 consecutive amino acid residues in the selected CDR, the selected amino acid sequence being a lead sequence; comparing the lead sequence profile with a plurality of tester protein sequences; selecting from the plurality of tester protein sequences at least two peptide segments that have at least 10% sequence identity with lead sequence, the selected peptide segments forming a hit library; determining if a member of the hit library is structurally compatible with the lead structural template using a scoring function; and selecting the members of the hit library that score equal to or better than or equal to the lead sequence. The selected members of the hit library can be expressed in vitro or in vivo to produce a library of recombinant antibodies that can be screened for novel or improved function(s) over the lead antibody.

The present invention provides a structure-based methodology for efficiently generating and screening protein libraries for optimized proteins with desirable biological functions, such as antibodies with high binding affinity and low immunogenicity in humans. In one embodiment, a method is provided for constructing a library of antibody sequences based on a three dimensional structure of a lead antibody. The method comprises: providing an amino acid sequence of the variable region of the heavy chain (VH) or light chain (VL) of a lead antibody, the lead antibody having a known three dimensional structure which is defined as a lead structural template; identifying the amino acid sequences in the CDRs of the lead antibody; selecting one of the CDRs in the VH or VL region of the lead antibody; providing an amino acid sequence that comprises at least 3 consecutive amino acid residues in the selected CDR, the selected amino acid sequence being a lead sequence; comparing the lead sequence profile with a plurality of tester protein sequences; selecting from the plurality of tester protein sequences at least two peptide segments that have at least 10% sequence identity with lead sequence, the selected peptide segments forming a hit library; determining if a member of the hit library is structurally compatible with the lead structural template using a scoring function; and selecting the members of the hit library that score equal to or better than or equal to the lead sequence. The selected members of the hit library can be expressed in vitro or in vivo to produce a library of recombinant antibodies that can be screened for novel or improved function(s) over the lead antibody.

The present invention provides a methodology for efficiently generating and screening protein libraries for optimized proteins with desirable biological functions, such as improved binding affinity towards biologically and / or therapeutically important target molecules. The process is carried out computationally in a high throughput manner by mining the ever-expanding databases of protein sequences of all organisms, especially human. In one embodiment, a method is provided for constructing a library of antibody sequences based on the amino acid sequence of a lead antibody. The method comprises: providing an amino acid sequence of the variable region of the heavy chain (VH) or light chain (VL) of a lead antibody; identifying the amino acid sequences in the CDRs of the lead antibody; selecting one of the CDRs in the VH or VL region of the lead antibody; providing an amino acid sequence that comprises at least 3 consecutive amino acid residues in the selected CDR, the selected amino acid sequence being a lead sequence; comparing the lead sequence with a plurality of tester protein sequences; and selecting from the plurality of tester protein sequences at least two peptide segments that have at least 15% sequence identity with the lead sequence, the selected peptide segments forming a hit library. The hit library of antibody sequences can be expressed in vitro or in vivo to produce a library of recombinant antibodies that can be screened for novel or improved function(s) over the lead antibody.

The present invention relates to a method for adjusting the affinity of a polypeptide to a target molecule by a combination of steps, including: (1) the identification of aspartyl residues which are prone to isomerization; (2) the substitution of alternative residues and screening the resulting mutants for affinity against the target molecule. In a preferred embodiment, the method of subtituting residues is affinity maturation with phage display (AMPD). In a further preferred embodiment the polypeptide is an antibody and the target molecule is an antigen. In a further preferred embodiment, the antibody is anti-IgE and the target molecule is IgE. In another embodiment, the invention relates to an anti-IgE antibody having improved affinity to IgE.

An antikine antibody binds to two, three, four, five or more CC chemokines, such as RANTES / CCL5, MIP-1α / CCL3, MIP-1β / CCL4, or MCP-1 / CCL2. Methods for affinity maturation and humanization of antikine antibodies as well as the production of hybridoma cell lines producing antikine antibodies by sequential immunization are also disclosed.

The present invention relates to a method for the generation of single chain immunoglobulins in a mammal. In particular, the present invention relates to a method for the generation of single chain camelid VHH antibodies in a mammal which undergo the process of class-switching and affinity maturation found within antibody producing B cells. Single chain antibodies generated using the method of the present invention and the uses thereof are also described.

The invention relates to the technical field of biotechnology and particularly relates to an anti-CD19 antibody and a preparation method and use thereof. CDR in a heavy chain variable region of the anti-CD19 antibody comprises CDR-H1 with an amino acid sequence shown in the formula of SEQ ID No. 1, CDR-H2 with an amino acid sequence shown in the formula of SEQ ID No. 2 and CDR-H3 with an amino acid sequence shown in the formula of SEQ ID No. 3. The CDR of a light chain variable region of the anti-CD19 antibody comprises CDR-L1 with an amino acid sequence shown in the formula of SEQ ID No. 4, CDR-L2 with an amino acid sequence shown in the formula of SEQ ID No. 5 and CDR-L3 with an amino acid sequence shown in the formula of SEQ ID No. 6. The FMC63 scFv is screened in affinity maturation through a phage display technology so that a high affinity single chain antibody against CD19 is obtained.

The present invention relates to humanisation of antibodies in vivo. The invention provides non-human vertebrates, cells, populations and methods useful for humanising chimaeric antibodies in vivo. Using the present invention it is possible straightforwardly and rapidly to obtain antigen-specific antibodies that are fully human (ie, comprising human variable and constant regions) and have undergone recombination, junctional diversification, affinity maturation and isotype switching in vivo in a non-human vertebrate system. Furthermore, such antibodies are humanised (eg, totally human)—and selected—totally in vivo, and as such the present invention harnesses in vivo filtering for expressibility, affinity and biophysical characteristics in the context of the desired human variable and constant region pairings. This is avoids problems of down-grading antibody characteristics when humanising the constant region of chimaeric antibodies in vitro.

The present invention provides a genetic method for tethering polypeptides to the yeast cell wall in a form accessible for binding to macromolecules. Combining this method with fluorescence-activated cell sorting provides a means of selecting proteins with increased or decreased affinity for another molecule, altered specificity, or conditional binding. Also provided is a method for genetic fusion of the N terminus of a polypeptide of interest to the C-terminus of the yeast Aga2p cell wall protein. The outer wall of each yeast cell can display approximately 104 protein agglutinins. The native agglutinins serve as specific adhesion contacts to fuse yeast cells of opposite mating type during mating. In effect, yeast has evolved a platform for protein-protein binding without steric hindrance from cell wall components. As one embodiment, attaching an scFv antibody fragment to the Aga2p agglutinin effectively mimics the cell surface display of antibodies by B cells in the immune system for affinity maturation in vivo. As another embodiment, T cell receptor mutants can be isolated by this method that are efficiently displayed on the yeast cell surface, providing a means of altering T cell receptor binding affinity and specificity by library screening.

The invention relates, in one aspect, generally to novel concept of guided selection of antibody variable domains, combination and expression entirely in vivo. An application is to produce multivalent polypeptides. The present invention relates to multivalent (eg, multispecific) antibodies, antibody chains and polypeptides, as well as heavy chain-only antibodies (H2 antibodies) that are devoid of light chains. The invention further relates to the selection, maturation and production of these in vivo in non-human vertebrates and non-human vertebrate cells. To this end the invention also relates to such non-human vertebrates and cells. The invention also relates to the provision of means to produce and select heavy chain-only antibodies and heavy chains comprising variable domains that have undergone affinity maturation.

The invention relates to the technical field of biotechnology and particularly relates to an anti-CD19 antibody and a preparation method and use thereof. The anti-CD19 antibody comprises a heavy chainvariable region and a light chain variable region. The complementarity determining region of the heavy chain variable region comprises CDR-H1 with an amino acid sequence shown in the formula of SEQ ID No. 1, CDR-H2 with an amino acid sequence shown in the formula of SEQ ID No. 2 or 3 and CDR-H3 with an amino acid sequence shown in the formula of SEQ ID No. 4. The complementarity determining region of the light chain variable region comprises CDR-L1 with an amino acid sequence shown in the formula of SEQ ID No. 5, CDR-L2 with an amino acid sequence shown in the formula of SEQ ID No. 6 and CDR-L3 with an amino acid sequence shown in the formula of SEQ ID No. 7. The FMC63 scFv is screened in affinity maturation through a phage display technology so that a high affinity single chain antibodyagainst CD19 is obtained.

The present invention relates to the manufacture of a diverse repertoire of functional heavy chain-only antibodies that undergo affinity maturation, and uses thereof. The invention also relates to the manufacture and use of a diverse repertoire of class-specific heavy chain-only antibodies and to the manufacture and use of multivalent polypeptide complexes with antibody heavy chain functionality, preferably antibody heavy chain binding functionality, constant region effector activity and, optionally, additional effector functions.The present invention also relates to a method of generation of fully functional heavy chain-only antibodies in transgenic mice in response to antigen challenge. In particular, the present invention relates to a method for the generation of human antigen-specific, high affinity, heavy chain-only antibodies of any class, or mixture of classes and the isolation and expression of fully functional VH antigen-binding domains.

The invention relates to the technical field of antibody engineering and specifically discloses an anti-PCSK9 monoclonal antibody. The invention comprises an amino acid sequence coding an antibody variable region and a CDR region as well as an acquisition method and an application of the monoclonal antibody. The monoclonal antibody disclosed by the invention is prepared by the following steps: screening out anti-PCSK9 monoclonal antibodies from a phage library; performing affinity maturation by a method of establishing phage library through strand displacement; screening the mutant libraries of light-chain CDR1, 2, and 3 regions of the monoclonal antibody obtained by primary screening, and selecting the monoclonal antibodies with relatively high affinity; and screening the mutant libraries of heavy-chain CDR1, 2, and 3 to finally obtain the anti-PCSK9 monoclonal antibody with high affinity. In the invention, the obtained PCSK9 antibody has good affinity on PCSK9 and can inhibit combination of the PCSK9 with ligand thereof and can be used for treating dyslipidemia, cardiovascular and cerebrovascular diseases and thrombosis-obstructive diseases.

The present invention describes transgenic animals with human(ized) immunoglobulin loci and transgenes encoding human(ized) Igα and / or Igβ sequences. Of particular interest are animals with transgenic heavy and light chain immunoglobulin loci capable of producing a diversified human(ized) antibody repertoire that have their endogenous production of Ig and / or endogenous Igα and / or Igβ sequences suppressed. Simultaneous expression of human(ized) immunoglobulin and human(ized) Igα and / or Igβ results in normal B-cell development, affinity maturation and efficient expression of human(ized) antibodies.