Q19 Discuss the molecular interactions between HIV and host cells, and how these interactions almost never lead to eradication of HIV from a person

Q19 Discuss the molecular interactions between HIV and host cells, and how these interactions almost never lead to eradication of HIV from a person

Answered by: Kara-Lee.Mepstead@student.griffith.edu.au

HIV interaction Host cell never lead to eradication

HIV persists and lives in the human body as a reterovirus. HIV utilizes the cells of the immune system for survival. This enables destruction of the immune system providing a safe guard for survival of HIV.

The HIV viral capsid contains 2x single stranded RNA molecules each joined to a reverse transcriptase molecule.

- high affinity CD4 antigen

- HIV: gp120 on envelope bind CD4 antigen of T lymphocytes & APC

- gp41 attatches co-reeptor fuse with cell & enter

- reverse transcriptase: RNA—transcribed DNA

- DNA dbStrand DNA Intergrase intergrate into host DNA

- 10 billion virions/day OR dormant

Initial: CD4 death

Latency period: escape detection, remain dormant lymphoid tissues, CD4 normal, peripheral viral burden low

Exhaust the immune system avoid eradication

- virus kill infected T4 cells

- killer T-cells destroy virus infected T-cells

- Detached gp120 & 41 bind & block CD4 receptors prevent T cells responding to foreign antigens

- soluable suppressor factor released by T4

- infect/disrupt/kill CD4 receptor containing cells (esp. APC)

- Virus-initiated auto-immune response to CD4 receptors destruction cells with receptors

AIDS development

- selection viral varients resistant to neutralizing Ab.

Late stage:

- significant loss immune function

- ↑ infection, cancer death

Variability: no 1 person infected with same coated HIV hard to treat