User:Sir Alok

How does HIV virus Infect human?

Due to various mode of transmission like unsafe sexual activities, using unsterilized equipments, the virus enters inside human blood. Then it directly gets attached with blood cells with CD4 molecules in their cell surface (eg:T4 helper lymphocytes). The virus along with viral rna and viral enzyme enters the T4 cells, then it produces viral enzyme reverse transcriptase so viral dna is formed from viral rna. Viral dna gets intercooperated with dna of T4 cells.At some time viral dna replicates producing large number of new viruses. These virus gets out to blood stream by lysis of T4cells. Then the new virua infect other T4 cells. T4 cells are required to body for regulation of body defence system. Once they are destroyed, body becomes defenceless and many oppurtinistic infections resulting in death of patient.

Refrence:
 * A textbook of biology by Dr. RP Singh,Trivuwan University, Nepal