Cellular Components of Immunity

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Questions and Answers

Which type of immunity is primarily associated with B lymphocytes?

Innate immunity

Adaptive immunity

Cell-mediated immunity

Humoral immunity (correct)

What mechanism do M.tuberculosis employ to evade the immune response?

Inhibit NF-kB signaling

Block phagosome-lysosome fusion (correct)

Mutate flagellin protein

Deplete antibodies

What is the function of the NS1 protein in West Nile virus?

Promotes phagosome acidification

Inhibits NF-kB and IRF activation (correct)

Enhances PRR signaling

Facilitates antibody binding

Which protein does Staphylococcus use to deplete antibodies?

Staphylokinase Signup and view all the answers

How do some pathogens interfere with the function of complement proteins?

By inactivating C3cBbC3 convertase Signup and view all the answers

Where do T lymphocytes mature in the human body?

Thymus Signup and view all the answers

Which of the following pathogens is associated with protease-mediated destruction?

Pseudomonas Signup and view all the answers

What is the role of the protein A in Staphylococcus?

Depletes antibodies Signup and view all the answers

What type of T cells does Class I MHC present peptide fragments to?

CD8+ T cells Signup and view all the answers

Where do the peptide fragments presented by Class II MHC come from?

Extracellular proteins Signup and view all the answers

Which of the following statements regarding T lymphocytes is correct?

They require peptide fragments for recognition. Signup and view all the answers

Which cells are considered professional antigen-presenting cells (APCs)?

Dendritic cells, macrophages, and B cells Signup and view all the answers

What is the typical length of peptide fragments recognized by T lymphocytes?

7-11 amino acids Signup and view all the answers

Which type of MHC presents antigen fragments to CD4+ T cells?

Class II MHC Signup and view all the answers

B lymphocytes can recognize which types of biomolecules?

Any kind of macromolecule Signup and view all the answers

What function does the Major Histocompatibility Complex perform?

Presents peptide fragments to T cells Signup and view all the answers

What are the two major classes of light chains in antibodies?

Kappa and Lambda Chains Signup and view all the answers

Which light chain is the dominant form in human immunoglobulins?

Kappa (κ) Chain Signup and view all the answers

What indicates an abnormal ratio of Kappa to Lambda light chains?

Presence of blood cancer Signup and view all the answers

How are the variable and constant regions of antibody chains differentiated?

Variable regions have different amino acid sequences. Signup and view all the answers

Which fragment of an antibody is responsible for binding to antigens?

Fragment Antigen Binding (Fab) Signup and view all the answers

What structure connects the heavy and light chains of an antibody?

Disulfide Bonds Signup and view all the answers

An increase in Lambda light chains compared to Kappa chains may suggest which condition?

Multiple Myeloma Signup and view all the answers

What is the purpose of the constant region of an antibody?

To maintain a consistent amino acid sequence Signup and view all the answers

What is a key advantage of vector-based vaccines?

They have no risk of reversion. Signup and view all the answers

What type of antigens can T cell independent antigens activate?

Short-lived plasma cells. Signup and view all the answers

Which of the following is NOT a challenge in the delivery of certain vaccines?

High cost of production. Signup and view all the answers

What is a potential safety benefit associated with using vector-based vaccines?

They avoid nuclear membrane barriers. Signup and view all the answers

What does the immune response to conjugated vaccines primarily promote?

IgM responses without T cell activation. Signup and view all the answers

Which pathogen is NOT mentioned as an example of a conjugated vaccine?

Hepatitis B. Signup and view all the answers

What is a significant characteristic of secreted toxins in the context of vaccines?

They are not designed to target memory cells. Signup and view all the answers

Which statement regarding the immune response in infants is true?

IgM production is prominent even without T cells. Signup and view all the answers

What is the primary method used to produce an attenuated vaccine?

Selection for avirulent organisms Signup and view all the answers

How many boosters are generally required for an attenuated vaccine?

Only a single booster is required Signup and view all the answers

Which of the following statements is true regarding inactivated vaccines?

They require multiple boosters due to antigen destruction Signup and view all the answers

What is a characteristic of the relative stability of attenuated vaccines?

Less stable and requires potent immunization Signup and view all the answers

Which process is used to inactivate pathogens in inactivated vaccines?

Exposure to gamma rays or chemicals Signup and view all the answers

Which aspect makes inactivated vaccines advantageous for developing countries?

They are more stable and easier to transport Signup and view all the answers

What challenge is typically associated with the storage of attenuated vaccines?

They often lose potency if not refrigerated Signup and view all the answers

What is a disadvantage of inactivated vaccines compared to attenuated vaccines?

They require more frequent boosters Signup and view all the answers

Study Notes

Cellular Evasion Mechanisms

Evasion Types: Pathogens utilize various strategies to evade detection and responses from the immune system.
Proteobacteria: Mutated flagellin evades recognition by Toll-Like Receptor 5 (TLR5), assisting in humoral immunity.
West Nile Virus: NS1 protein inhibits NF-kB and IRF signaling pathways, blocking PRR signaling and suppressing immune activation.
Mycobacterium tuberculosis: Prevents phagocyte killing by interfering with phagosome-lysosome fusion and acidification.
Staphylococcus aureus: Depletes antibodies through protein A, which removes IgG via staphylokinase.
Complement Systems: Binding and inactivation of complement proteins occur through mechanisms like SCIN from S. aureus disrupting C3cBbC3 convertase.
Protease Activity: Pseudomonas and Streptococcus produce elastase alkaline phosphatase for protease-mediated destruction.

Major Histocompatibility Complexes (MHC)

Class I MHC: Presents peptide fragments from cytosolic proteins to CD8+ T cells.
Class II MHC: Presents peptide fragments from extracellular proteins to CD4+ T cells, found in professional antigen-presenting cells like dendritic cells and macrophages.
Cluster of Differentiation (CD): Surface proteins on lymphocytes that assist in their identification and classification.

Activation of Adaptive Immunity

B Lymphocytes: Recognize various macromolecules (proteins, polysaccharides, lipids, and nucleic acids) and generate antibodies.
T Lymphocytes: Recognize only peptide fragments presented by MHC, specifically 7-11 amino acids in length.
MHC Presence: MHCs are located on all nucleated cells and are essential for T cell recognition of antigens.

Effector Functions of Adaptive Immunity

B Cells: Central to humoral immunity, they produce antibodies that mediate responses against pathogens.
Antibody Structure: Composed of two heavy chains and two light chains linked by disulfide bonds, containing variable and constant regions.
Light Chain Types:
- Kappa (κ) Chain: Derived from a single exon and dominant in human immunoglobulins.
- Lambda (λ) Chain: Arises from multiple exons, making up 40% of human immunoglobulins.

Antigen-Antibody Interaction

Antibodies: Produced in response to foreign antigens; crucial for humoral immunity.

Vaccine Types and Properties

Attenuated Vaccines:
- Produced by selecting avirulent organisms; require only one booster.
- Less stable but can be mass-produced.
Inactivated Vaccines:
- Consist of inactivated pathogens that need multiple boosters; more stable for distribution.

Conjugated and Vector-Based Vaccines

Conjugated Vaccines: Activate immune systems to recognize bacteria, able to induce B cell response independently of T cells.
Vector-Based Vaccines: Use attenuated pathogens to deliver target antigens, combining the benefits of live vaccines without reversion risk.

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Description

This quiz focuses on the cellular components of the immune system, particularly the evasion mechanisms employed by various bacteria. Students will explore how B cell and T cell lymphocytes function and their development from bone marrow. Test your understanding of immunological concepts and the role of pattern recognition receptors.