Stable immunogens comprising portions of the inner domain (ID) of the Human Immunodeficiency Virus (HIV-1) gp120 protein are provided. These ID immunogens selectively present the gp120 C1/C2 region in its CD4-bound state within a minimal structure. These ID immunogens can be used to vaccinate subjects against infection with HIV, the causative agent of Acquired Immunodeficiency Syndrome (AIDS). The immunogens can also be used as targets in screening to identify small molecule or peptide inhibitors that block HIV-1 viral entry and attachment steps, and as probes for identifying gp120 C1/C2 region-specific antibodies.

The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

HIV-1 Env ectodomain trimers stabilized in a prefusion mature closed conformation and methods of their use and production are disclosed. In several embodiments, the HIV-1 Env ectodomain trimers and/or nucleic acid molecules can be used to generate an immune response to HIV-1 in a subject. In additional embodiments, the therapeutically effective amount of the HIV-1 Env ectodomain trimers can be administered to a subject in a method of treating or preventing HIV-1 infection.

The disclosure provides compositions and methods for sensitizing primary HIV-1, including transmitted/founder viruses, to neutralization by monoclonal antibodies, e.g., those directed against CD4-induced (CD4i) epitopes and the V3 region. In certain embodiments, the disclosure relates to the use of small molecules as microbicides to inhibit HIV-1 infection directly and to sensitize primary HIV-1 to neutralization by readily elicited antibodies.

HIV-1 envelope proteins and fragments that possess naturally occurring and novel engineered epitopes that can be used to elicit (and are recognized by) broadly neutralizing antibodies.

This disclosure provides HIV immunogens and use thereof for generating an immune response in a subject. Also disclosed is a method of isolating anti-HIV antibodies and use thereof. This disclosure further provides a method for treating or preventing a human immunodeficiency type 1 (HIV-1) infection in a subject using the disclosed HIV immunogens and/or antibodies.

Disclosed herein are trimeric polypeptide pharmaceutical compositions comprising three monomers, each monomer comprising a polypeptide having the amino acid sequence of the N-terminal heptad repeat (NHR or HR1) or C-terminal heptad repeat (CHR or HR2) of the transmembrane glycoprotein of human immunodeficiency virus (HIV) and a trimerization motif.

The present invention relates to a method for detecting and/or quantifying human immunodeficiency virus (HIV) specific antibodies in a sample of a subject comprising the step of determining the presence and/or amount of antibodies binding to a) a peptide consisting of the amino acid sequence AIVCTRPNNNTRKSIRIGPGQVFYT (SEQ. ID No. 1), or b) a homolog having at least 70% identity with a peptide of a), or c) a fragment of a peptide of a) or b) consisting of 15 to 24 amino acid residues in said sample.

Disclosed herein are mosaic conserved region HIV polypeptides and immunogenic polypeptides including one or more of the mosaic conserved region polypeptides. In some embodiments, the immunogenic polypeptides are included in an immunogenic composition, such as a polyvalent immunogenic composition. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject having or at risk of HIV infection. In some embodiments, the methods include inducing an immune response in a subject comprising administering to the subject at least one of the disclosed immunogenic polypeptides or a nucleic acid encoding at least one of the immunogenic polypeptides.

The present invention provides novel scaffolded HIV-1 vaccine immunogens. Some of the scaffolded immunogens contain a soluble gp140 trimer linked to the N-terminus of the nanoparticle subunit and a T-helper epitope that is fused via a short peptide spacer to the C-terminus of the nanoparticle subunit. Some other immunogens of the invention contain a soluble gp140 trimer protein that is linked to a stable nanoparticle via a short peptide spacer that is a T-helper epitope. Some of the scaffolded immunogens contain a gp140 trimer immunogen presented on a nanoparticle platform formed with I3-01 protein, E2p, or variants of protein 1VLW. Also provided in the invention are nucleic acids that encode the various vaccine immunogens described herein, and expression vectors and host cells harboring the nucleic acids. The invention further provides methods of using the scaffolded HIV-1 vaccine immunogens for preventing or treating HIV infections.