HIV TROPISM Meaning and
Definition
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HIV tropism refers to the ability of the Human Immunodeficiency Virus (HIV) to infect and replicate in specific types of cells within the host's immune system. It is a crucial factor in understanding the pathogenesis and progression of HIV infection. The virus primarily targets CD4+ T cells, which play a vital role in orchestrating the immune response. However, HIV can also infect other key immune cells, such as macrophages and dendritic cells.
Tropism is determined by the presence or absence of specific molecules on the surface of cells that act as entry receptors for the virus. HIV primarily uses two main chemokine receptors, namely CCR5 and CXCR4, to gain entry into host cells. The presence of CCR5 is associated with the R5 tropism, while the presence of CXCR4 allows for X4 tropism. Some strains of HIV can use both receptors, having dual or mixed tropism. This variable tropism is often associated with disease progression and response to antiretroviral therapy.
Monitoring HIV tropism is essential for selecting appropriate treatment options. A tropism test is performed to determine which receptors the virus can bind to, guiding the use of specific antiretroviral drugs that can target the respective receptor. In cases where the virus displays CXCR4 tropism, certain antiretrovirals may be less effective. Thus, understanding the HIV tropism of an individual's viral strain helps inform treatment decisions and optimize therapeutic outcomes.
Etymology of HIV TROPISM
The word "hiv tropism" is a combination of two terms: "HIV" and "tropism".
The term "HIV" stands for Human Immunodeficiency Virus, which is the virus that causes AIDS (Acquired Immunodeficiency Syndrome). The acronym "HIV" was coined in the early 1980s when scientists discovered the virus.
The term "tropism" in the context of HIV refers to the preference or ability of the virus to infect certain types of cells or tissues in the body. In the case of HIV, tissue tropism is related to the specific target cells that the virus can infect. HIV primarily infects CD4+ T cells (a type of white blood cell that is crucial for the immune system functioning), but also has tropism for other cells such as macrophages and dendritic cells.
