Despite therapeutic advances, human immunodeficiency virus (HIV) is still a pervasive disease, with approximately 37 million people infected worldwide. Peptides have become popular therapeutic agents, as these proteins offer structural diversity for many different diseases. Several peptides were commercially developed as HIV therapeutics, demonstrating the high potential for peptides in treating HIV. 

Antiretroviral therapy (ART) has changed the prognosis of HIV-1 infection to a chronic illness that, in most cases, can be managed or controlled. Integrase strand transfer inhibitors (INSTIs) and reverse transcription inhibitors are essential components of ART drug cocktails. In compliant individuals, ART has been found to block viral replication completely. Additionally, blocking viral replication can prevent the emergence of drug resistance.

Chimeric antigen receptors (CARs) combine an antibody-based binding domain (and single chain fragment variable region, scFv) with T cell receptor signaling domains (CD3 zeta with a costimulatory domain, typically CD28 or 41BB). When T cells express CARs, they are activated in a major histocompatibility complex- (MHC) independent manner to kill tumor cells expressing the target to which the scFv binds.  CAR T cells targeting the B cell antigen CD19 have resulted in remissions in 60-80% of patients with pre-B cell precursor acute lymphoblastic leukemia (BCP-ALL).

Research and clinical applications of induced pluripotent stem (iPS) cells are currently limited by reprogramming methods that may modify the host genome, and therefore be potentially unsafe and problematic for use in basic research, cell-based therapies, and drug-discovery applications. 

Gene therapy research has yielded FDA-approved treatments for an array of diseases. However, challenges facing nucleic-acid based therapeutics include non-specific delivery and degradation of the nanoparticles. NCI investigators have developed a solution to address these challenges in their novel nucleic-based therapy based on the conditional activation strategy. 

Chk2 is a protein kinase activated in response to DNA double strand breaks. In normal tissues, Chk2 phosphorylates and thereby activates substrates that induce programmed cell death, or apoptosis, via interactions with p53, E2F1, PML proteins. In cancer tissues, where apoptosis is suppressed, Chk2 phosphorylates and inactivates cell cycle checkpoints (via interactions with Cdc25, phosphatases and Brca1 proteins), which allows cancer cells to repair and tolerate DNA damage.

Adoptive cell therapy (ACT) is a breakthrough form of cancer immunotherapy that utilizes autologous, antitumor T cells to attack tumors through recognition of tumor-specific mutations, or neoantigens. A major hurdle in the development of ACT is the exhausted phenotype exhibited by many neoantigen-specific T cells, which limits their efficacy and prevents a sustained immune response. 

Advanced stage cancers are typically marked by metastases of the primary cancer to secondary sites such as lungs, liver, and bones. Such metastatic cancers result in strikingly low 5-year survival rates, underscoring the need for novel therapeutics. For example, bone metastasis of primary breast cancer has a 5-year survival rate of 13%, lung cancer only 1%. There is a need for targeted therapy options specific to metastases. One approach to targeting metastases is to reduce cancer cell migration and invasion.

Most early work on CD133 was carried out using one of two monoclonal antibodies (mAbs), AC133 and AC141, which recognize an undefined glycosylated epitope of CD 133.

Current methods to deliver proteins into cells (e.g., using retrovirus, DNA transfection, protein transduction, microinjection, complexing the protein with lipids, etc.) have many shortcomings, such as lack of target specificity toxicity, or unwanted random integration into the host chromosome.  Protein transduction is an emerging technology for delivering proteins into cells by exploiting the ability of certain proteins to penetrate the cell membrane.  However, the majority of the proteins delivered by this means are usually trapped and subsequently degraded in the endosomes-lyso