Provided herein are, inter alia, antibodies, antigen-binding antibody fragments, cells, polynucleotides, compositions, kits, and methods relating to the detection of HBV protein X (HBx), e.g., in vitro and in vivo. Included are antibodies and fragments thereof that bind HBx, as well as kits, cells, and compositions comprising such antibodies and fragments.

The present disclosure relates to cell penetrating anti-DNA binding proteins. Compositions comprising these binding proteins may be may be useful for delivering agents to cells and treating diseases such as cancer.

Provided herein are antigen-binding constructs such as antibodies that bind to the RRM-1 domain of TDP-43. The antigen-binding constructs are capable of blocking the interaction of TDP-43 with NF-κB in cells. Also provided herein are method of using the antigen-binding constructs in the treatment of diseases associated with TPD-43 proteinopathy, such as amyotrophic lateral sclerosis (ALS), frontotemperal lobar degeneration (FTLD), Lewy body disease and motor neuron disease.

The present invention relates to a method of localizing an intact immunoglobulin-format antibody in cytosol by permeating membrane of cells. The present invention also relates to a light-chain variable region (VL) that induces an intact immunoglobulin-format antibody to penetrate the membrane of living cells and be localized in the cytosol, and to an antibody comprising the same. The present invention also relates to a biologically active molecule fused to the antibody and selected from the group consisting of peptides, proteins, small-molecule drugs, nanoparticles and liposomes. The present invention also relates to a composition for prevention, treatment or diagnosis of cancer, comprising: the antibody; or a biological active molecule fused to the antibody and selected from the group consisting of peptides, proteins, small-molecule drugs, nanoparticles and liposomes. The present invention also relates to a polynucleotide that encodes the light-chain variable region and the antibody. The present invention also relates to a method for producing an antibody which penetrates cells and is localized in the cytosol.

According to the method of the present invention, which allows an intact immunoglobulin-format antibody to actively penetrate living cells and be localized in the cytosol, the antibody can penetrate living cells and be localized in the cytosol, without having to use a special external protein delivery system. Moreover, the use of the cytosol-penetrating light-chain variable region according to the present invention and the intact immunoglobulin-format antibody comprising the same can penetrate cells and remain in the cytosol, without affecting the high specificity and affinity of a human antibody heavy-chain variable region (VH) for antigens, and thus can be localized in the cytosol which is currently classified as a target in disease treatment based on small-molecule drugs, and at the same time, can exhibit high effects on the treatment and diagnosis of tumor and disease-related factors that show structurally complex interactions through a wide and flat surface between protein and protein. In addition, these can selectively inhibit KRas mutants, which are major drug resistance-associated factors in the use of various conventional tumor therapeutic agents, and at the same time, can be used in combination with conventional therapeutic agents to thereby exhibit effective anticancer activity.

The present invention relates to active form specific anti-Rho GTPase conformational single domain antibodies and their uses in particular in the therapeutic and diagnostic fields. In particular, the present invention relates to a single domain antibody wherein the amino acid sequences of CDR1-IMGT, CDR2-IMGT and CDR3-IMGT have at least 90% of identity with the amino acid sequences of the CDR1-IMGT, CDR2-IMGT and CDR3-IMGT of the H12, B6, 4P75, 4SP1, 4SNP36, 4SNP61, 5SP10, 5SP11, 5SP58, 5SNP47, 5SNP48, 5SNP65, B20, B15, B5, B71, E3, A6, G12, NB61, 212B, 111B or 404F (hs2dAb) single domain antibody which are defined in Table B.

Combination therapies including administering a subject in need thereof a cell-penetrating binding protein, such as an antibody, and an immune checkpoint modulator are provided. Typically, the cell-penetrating binding protein can induce DNA damage or reduce DNA damage repair in an effective amount to activate the innate immunity inflammatory pathway in target cells such as cancer cells or infected cells. For example, in some embodiments, the cell-penetrating binding protein increases induced p21 and/or p27 protein expression, increases accumulation of single-strand DNA in the cytosol, increases phosphorylation of STAT1, or a combination thereof in target cells. The subject can have cancer or an infection and the combination of the cell-penetrating binding protein and the immune checkpoint modulator reduce one or more symptoms of cancer or infection, preferably to a greater degree than administering the subject the same amount of cell-penetrating binding protein alone or the same amount of immune checkpoint modulator alone.

Active forms of specific anti Rho GTPase conformational single domain antibodies are useful in the therapeutic and diagnostic fields. In particular, single domain antibodies wherein the amino acid sequences of CDR1-IMGT, CDR2-IMGT and CDR3-IMGT have at least 90% of identity with the amino acid sequences of the CDR1-IMGT, CDR2-IMGT and CDR3-IMGT of the H12, B6, 4P75, 4SP1, 4SNP36, 4SNP61, 5SP10, 5SP11, 5SP58, 5SNP47, 5SNP48, 5SNP65, B20, B15, B5, B71, E3, A6, G12, NB61, 212B, 111B or 404F (hs2dAb) are defined in Table B.

The present invention refers to a method for determining the ability of an immunoglobulin to bind to a post-translationally modified target in an intracellular environment, which folds and it is post-translationally modified as a native protein intracellularly. The present invention also refers to antibodies obtained by the above method and uses thereof.

This disclosures provides methods of treatment of idiopathic pulmonary fibrosis (IPF) with an intrabody. Methods of screening for IPF are also provided. Methods for inhibiting fibroblast proliferation, fibroblast differentiation, and/or fibroblast activation of T cells with an intrabody are also provided.

The present disclosure relates to a cytosol-penetrating antibody and the use thereof, and more specifically to identification of a structural mechanism that induces escape from endosomes into the cytosol after cellular internalization into living cells through a cell membrane protein, a light-chain variable region and/or heavy-chain variable region, which is based on this identification and has a significantly improved ability to escape from endosomes into the cytosol, a cytosol-penetrating antibody comprising the same, a method for producing the same, and the use thereof.