Haptens: Small organic molecule (e g. 1-Fluoro-2,4-dinitrobenzene)

Haptens: Small organic molecule (e.g. 1-Fluoro-2,4-dinitrobenzene)

• Haptens: Small organic molecule (e.g. 1-Fluoro-2,4-dinitrobenzene)

• Not Immunogenic by themselves

• Can be immunogenic when attached to an immunogenic macromolecular carrier

• The Anti-hapten antibody so generated will bind the Hapten

• Epitope: A region of a macromolecular antigen that is actually an antigenic determinant,

• a molecular sub-region that is actually recognized and bound by an Antibody or T-Cell Receptor

• (See Figure 4 “Structural definition of the 37.7H epitope on Lassa Virus Trimer)

Cancer Antigens as Targets for Therapy

• Cancer Antigens as Targets for Therapy

• Antibodies as Anti-cancer Agents

• Radioactively-labeled Antibodies

• Cytolytic Antibodies

• Specifically-activated Cytotoxic T-Cells as Anti-Cancer Agents

• Specifically Activated Antigen-presenting Cells (Tc).

• Specifically Activated Helper T-Cells (TH)

Caused by Gram Negative Bacterial Endotoxins: (Endotoxins = Agent is in the Outer Membrane)

• Caused by Gram Negative Bacterial Endotoxins: (Endotoxins = Agent is in the Outer Membrane)

• Examples -

• E. coli

• Pseudomonas aeruginosa

• Neisseria meningitidis

• Meningococcus

• 70,000 Deaths per year

• Diarrhea, Fever, Blood Clotting, Blood Pressure Drop

• Macrophage Activation by Endotoxin:

• Generates systemic cytokine production -

• IL1 and TNF-alpha (Tumor necrosis factor)

Exotoxins = Secreted or Presented Membrane Bound:

• Exotoxins = Secreted or Presented Membrane Bound:

• Act as "Superantigens"

• Examples -

• Staphylococcus aureus:

• TSST1 (Toxic Shock Syndrome Toxin)

• Streptococcus pyrogenes - Rheumatic fever and shock

• Staphylococcus enterotoxins: Food poisoning

• Superantigens cross-link TCR with Antigen-presenting Cell MHC Class II Proteins

• Again Generates systemic cytokine production – IL1 and TNF-alpha (Tumor necrosis factor)