4- HIV

Question 1

taxonomy of HIV

Answer 1

retroviridae lentivirus

-causing Human immunodeficiency virus

Question 2

morphology HIV

Answer 2

• spherical
  -complex
• double (=2 Single strands) RNA (+ve)
• each RNA strand linked to enzyme ‘reverse transcriptase’
• Surface antigens:
• gp120 = for adhesion
• gp41 = for penetration
• capsid protein = for identification

Question 3

cultivation of HIV

Answer 3

cell lines of T-cells (T-helper)

Question 4

antigenic properties + virulence of HIV

Answer 4

• gp120 = for adhesion to “CD4”receptor cells (found on T-helper cells )
• gp 41 = for penetration
• capsid protein = for identification

Question 5

enzyme of HIV

Answer 5

• protease
• integrase

Question 6

pathogenesis of HIV

Answer 6

• source = infected person (blood and fluid secretions)
• trans. method=
  1)sexual contact
  2) blood contact (organ donation & needle sharing)
• gate = CD4 receptors on T-helper cells /on other immunity cells
• pathogenesis = (cytopathogenic)
  -gp120 attaches to CD4 receptors on T-helper cells
  -gp41 helps penetrate
  -“decapsidization” by protease enzymes (=virus sheds its own capsid to release its viral RNA)
• Reverse transcriptase enzyme= transcripts viral-RNA into viral-DNA
• integrase enzyme = integrates viral-DNA into host’s DNA
• replication of this integrated DNA.
• virus decreases cell function but doesn’t kill it
• the cytopathic activity occurs by vicious cycle
• since T-helpers function is to give information about foreign antigens to T-killers & B cells
• the immune cells end up targeting & killing its own T-helper cells.
• therefore making the host susceptible /blind to any diseases/infections because T-helper cells/CD4 receptors no longer present to give the information about presence of foreign antigens

Question 7

CLINICAL MANIFESTATION of HIV

Answer 7

• AIDS (acquired immune deficiency syndrome)
• AIDS associated diseases
• getting infections more often.

Question 8

diagnosis of HIV

Answer 8

• Western Boltt
• ELISA

Question 9

treatment of HIV

Answer 9

Anti-Retroviral preparation of inhibitors

(by trying to inhibit the replication process of viral-DNA)
only dec. effect BUT doesn’t treat the causative agent

Question 10

prophylaxis of HIV

Answer 10

NO vaccine (due to
1:mutation of virus
2: immune system will be too weak to even fight the vaccine sample)