Human Health and Disease

Immunity, Basic concepts of immunology - vaccines; cancer, HIV and AIDS


  • Two components of Acquired immunity are (i) Antibody mediated Immune system (Humoral mediated immunity)(fluid) (ii) Cell mediated immunity.
  • Antibodies are produced by Balls which are of 2 types (i) Plasma Ball and (ii) Memory Ball. (Primed B-cell)
  • B cells are activated when antigens are bound over the ourface and the antibodies are produced through a mechanism of cloned selection.
  • Cell mediated Immunity is induced by T cells which is of 4 different types
    → T helper cells (TH)
    → T cytotoxic cells (killer)(Tc)
    → Memory T cells
    → Supprenor T cells
  • T helper cells have two types of receptor namely CD4 and CD8 which binds with MHC II and MHCI [Major Histo compatibility complex] respectively.
Primary Immune Response Secondary Immune Response
Occurs as a result of primary contact with an antigen Occurs as a result of second and subsequent exposure of same antigen
Responding Cell : B/T cell Memory Cell
Log phase : 4 - 7 days 1 - 4 days
First antibody produced ⇒ Ig M and small amount of IgG too is produced Mainly IgG antibody is produced small amount of IgM are also produced
  • Structure of an antibody :
  • Types of Antibodies (Immunoglobulins)
    ⇒ Ig G - 80%
    ⇒ Ig A [dimer] - 10 - 15%
    ⇒ Ig m [Pentamer] - 5 - 10%
    ⇒ Ig E - 0.002%
    ⇒ Ig D - 0.2%
  • Monoclonal antibodies (MAB's) are called as magic bullets which are highly specific for a disease, they are produced through Hybridoma technique using myeloma and B cell and HAT medium
  • Antibody - Antigen reaction
    ⇒ Agglutination [Antigen - large / easily sedimented particles]
    ⇒ Precipitation [Antigen - soluble ]
    ⇒ Opsonization [Antibody coating over bacteria]
    ⇒ Neutralization [Antibody block the sites on bacteria / viruses through which they enter the cell]
  • Abnormal (or) uncontrolled cell division which invade or destroy surrounding tissues is the condition termed as cancer.
  • Cancer is of 2 types based on its nature (i) Benign [non cancerous type which is confined that produces limited damage (and) (ii) Malignant [latent stage, which when enters the blood undergoes metastasis]
  • Cancerous cells has no property like contact inhibition.
  • Detection of cancer
    → Bone marrow Biopsy
    → Pap's Test [arvix / genitel tract]
    → CT (Computed Tomography)
    → Mammography [breast cancer]
    → Ames test (bacterial test to test mutation)
    → MRI [Magnetic Resonance Imasing]
  • HIV and AIDS [worlds AIDS day - Dec-1; worlds AIDS Capital - South Africa]
  • Acquired Immuno Deficiency syndrome is a disorder of cell mediated Immune system where there is reduction in the number of TH(helper T cells) which stimulate antibody production by B cells.
  • Specification of the virus
    ⇒ diameter : 90 - 120 nm
    ⇒ Genome : 2 single stranded RNA filament (RT)
    ⇒ Enzyme : Reverse Transcriptase ; Integrase
    ⇒ Covering : Lipid bilayer / 2 protein coats
    ⇒ Covering Contains : glycoprotein spikes [gp 41 / gp 120]
  • After the viral entry into the body, it enters through macrophages where RNA of virus replicates to form viral DNA with the help of RT and then the DNA gets integrated into the host cell's DNA and directs the infected cells to produce viruses.
  • The macrophages produce virus, act like a HIV factory
  • As the quantity of helper T lymphocytes decreases in the body, the person starts suffering from bacterial infections, viral / even parasites like Toxoplasma infects
  • HIV virus transmits through following factors.
    ⇒ Transfusion of infected blood (or) blood products
    ⇒ Use of contaminated needles / drugs / vaccines / razors
    ⇒ sexual intercourse with an infected partner without condom
    ⇒ Artificial insemination / organ transplantation.
  • Diagnosis : ELISA / western blotting (confirmation)
  • Treatment : Zidovudine / Azidothymidine / Didanosine
  • ARC (AIDS Related complex) is the mild form of AIDS / also called as prodromal AIDS
  • Addiction is of 3 types - (i) Drug (ii) Tobaco and (iii) Alcohol
  • Non medical use (or) non prescribed use (or) for pleasure of drugs are taken, it is defined as addiction
  • Drugs are of 2 types (i) Psychotrophic drugs (or) mind turning (or) mood alternating drugs (ii) Psychedelic drugs
  • Alcohol is not a stimulant but a depressant, which is generally absorbed by small intestive and stomach, transfers to liver and increases fat metabolism
  • It causes Mallory - Weiss Syndrome, where in acute condition causes oesophagitis and gastritis
  • Alcohol anonymous is a fellowship of men and women who. help each other with their common problem with alcoholism. [world wide organization]
  • Tobacco is obtained from Nicotiana Tobacum N. rustica which belongs to the family solanaceae.
  • Major stimulatory components of tobacco products is tobacco / cigarette - is Nicotive which belongs to alkoloid and it is a habituating drug.

Part-1: Watch this video for the topic from 4:55 to 56:13

Part-2: Watch this video for the topic from 5:44 to 54:44

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