Which receptors are essential for HIV entry into host cells?

HIV entry into host cells is a complex process that involves specific interactions between the virus and cell surface receptors. The primary receptor necessary for HIV to attach and enter cells is CD4, which is found on the surface of T-helper cells, among other immune cells. However, CD4 alone is not sufficient for entry; HIV requires additional co-receptors to mediate the fusion of the viral envelope with the host cell membrane.

The necessary co-receptors for HIV entry are CCR5 and CXCR4. These are chemokine receptors that HIV uses, depending on the strain of the virus and the cells it is infecting. CCR5 is typically utilized by "R5" strains of HIV, while "X4" strains use CXCR4. Many individuals have a variant of the CCR5 receptor that can offer resistance to HIV infection, but in the majority of cases, the interaction between CD4, CCR5 or CXCR4, and the viral envelope glycoproteins (specifically gp120 and gp41) is essential for successful viral entry.

Interferon receptors are involved in the immune response to viral infections but do not play a direct role in the entry of HIV into cells. Therefore, the answer identifying CCR5 and CX