HIV research

CD4+ T-helper cells (Th) are the white blood lymphocytes expressing surface glycoprotein antigen CD4. These T-helper cells play an important role in the adaptive immune system by releasing T cell cytokines that help other immune cells to suppress or regulate immune responses. CD4+ T-helper lymphocytes can be divided into two types (Th1 and Th2) based on their cytokine secretion. Th1 cells are involved in cell-mediated immune response to intracellular pathogens and delayed-type hypersensitivity reactions.

Research antibodies have long been used to advance HIV/Aids research, however researchers at the California Institute of Technology have recently published a study [PMID: 22033520] developing a new antibody that may someday be used clinically to neutralize HIV. Beginning with a naturally occurring antibody (NIH45-46) purified from HIV positive patients, the researchers modified the antibody using a technique called structure-based rational design.

CD4 is a member of the cluster of differentiation family of proteins, mainly expressed on the surface of thymocytes and a specific subset of mature T-cells. CD4 antibody studies have also shown it expressed on monocytes, cortical cells, microglial cells, dendritic cells and macrophages. The CD4 antibody is widely used in cell marker studies, CD4 being one of the most common CD markers in use.

Antibody studies into the human immunodeficiency virus (HIV) centre around Gag, a highly complex polyprotein that has so far defied attempts to unravel its complex and varied modes of action. Now, a team from the NIST Center for Neutron Research have revealed a new model which has allowed the protein to be studied in far more clarity. The hope with antibody suppliers is that it will pave the way to understanding many more large, unfathomable proteins.