A novel human bladder cancer marker AG-CD71 and a monoclonal antibody ABC71 for preventing AG-CD71 are provided. The human bladder cancer marker AG-CD71 is an abnormal glycosylated transferrin receptor TFRC; the abnormal glycosylated transferrin receptor TFRC refers to the TFRC carrying a saccharide structure Fucal-4(GlcNAcbl-3)[6OSO3]GlcNAc as an epitope. Also provided is an antibody for the human bladder cancer marker AG-CD71; the antibody is the monoclonal antibody ABC71 specific for the human bladder cancer AG-CD71; the monoclonal antibody is secreted from the hybridoma cell strain the preservation number of which is CGMCC No. 14312.

Provided herein are polypeptides that bind to a transferrin receptor, methods of generating such polypeptides, and methods of using the polypeptides to target a composition to a transferrin receptor-expressing cell.

Methods of treating or preventing a disease or disorder are disclosed comprising administering to a subject in need thereof an effective amount of a nucleic acid compound comprising, or consisting of, a nucleic acid sequence capable of binding to a transferrin receptor (TfR) and an effective amount of an inhibitor of DNA synthesis. Also disclosed is a nucleic acid compound comprising, or consisting of, a nucleic acid sequence having at least 85% sequence identity to SEQ ID NO: 1, wherein said nucleic acid sequence is at least 30 nucleotides in length and at most 50 nucleotides in length, and wherein the nucleic acid sequence is capable of binding to a transferrin receptor (TfR).

In some aspects, the present invention provides chimeric transferrin receptor (TfR) polynucleotides and polypeptides. In other aspects, this invention provides chimeric TfR transgenic animal models and methods of using the animal models to identify therapeutics that can cross the blood-brain barrier.

The present disclosure relates to polypeptides, such as fibronectin type III (FN3) domains that can bind CD71, their conjugates, isolated nucleotides encoding the molecules, vectors, host-cells, as well as methods of making and using the same.

The present disclosure relates to polypeptides, such as fibronectin type III (FN3) domains that can bind CD71, their conjugates, isolated nucleotides encoding the molecules, vectors, host-cells, as well as methods of making and using the same.

The invention relates to constructs, cells and methods for modulating the immune system that optimize presentation of CD4 and CD8 epitopes to antigen-presenting cells and transfection into cells. Epitopes to either self antigens or non-self antigens can be used to optimize either a tolerance or immunogenicity to those epitopes, respectively. Certain new constructs encode one or more dominant, disease-driving epitopes (CD4) targeted for MHCII processing within the endosomes of a cell and one or more epitopes (CD8) targeted for MHCI processing within the cytosol of the cell, to produce the maximum antigen/epitope presentation in the immune system, and further include an MHCII activator sequence. Alternatively, the new constructs encode CD4 and CD8 epitopes operably linked to a secretion signal.

Provided herein, inter alia, are nucleic acid compounds capable of binding transferrin receptor on a cell and internalizing into said cell. The compositions provided herein may be useful for delivering therapeutic and diagnostic agents to a cell. Further provided are pharmaceutical compositions and methods of treatment using nucleic acid compounds provided herein.

Provided herein, inter alia, are nucleic acid compounds capable of binding transferrin receptor on a cell and internalizing into said cell. The compositions provided herein may be useful for delivering therapeutic and diagnostic agents to a cell. Further provided are pharmaceutical compositions and methods of treatment using nucleic acid compounds provided herein.

Disclosed herein are compositions, reagents, and methods that can be used to observe multiple targets. The targets can be observed using a variety of methods, for example, by fluorescence, EM, and CLEM. The systems and methods involve the use of self-sorting coiled-coil heterodimers that label multiple proteins in a sample. These compositions, interchangeably termed “VIP tags” herein can be used to efficiently label cellular proteins with high specificity.