Immunology Midterm II Review

Vocabulary practice flashcards covering essential concepts in B-cell development, antibody functions, T-cell subsets, antigen presentation, HIV immunology, and host defense from Immunology Midterm II.

Bone marrow

Primary lymphoid tissue where B cells develop.

Secondary lymphoid tissues

Sites of antigen-driven B-cell activation, including the lymph nodes and spleen.

Heavy chain

The immunoglobulin chain that undergoes rearrangement first, followed by the light chain.

Germinal centers

Specialized microstructures where affinity maturation and isotype switching take place.

Receptor editing

New light-chain rearrangement that occurs to change a self-reactive B-cell receptor.

Naïve lymphocytes

Mature lymphocytes that have not yet been activated by their specific antigen.

Memory B cells

B cells that respond faster and often with higher-affinity antibodies upon re-exposure to antigen.

IgG

The main antibody in serum, capable of crossing the placenta via the neonatal Fc receptor (FcRn).

Neonatal Fc receptor (FcRn)

The receptor through which IgG crosses the placenta.

IgA

Antibody that protects mucosal surfaces and is also present in breast milk.

IgM

The antibody produced first in a primary immune response; secreted forms commonly assemble into pentamers.

IgE

The antibody isotype associated with allergic asthma.

IgD

An antibody that acts as an antigen receptor on mature naïve B cells.

Th1 cells

T helper cells whose main function is to activate macrophages, especially against intracellular pathogens.

Interferon gamma (IFN-γ)

The characteristic cytokine produced by Th1 cells.

IL-4

The characteristic cytokine of Th2 cells, supporting type 2 and antibody responses.

Helper T-cell markers

Surface markers CD3+ and CD4+ that identify helper T cells.

Regulatory T cells

Cells that suppress excessive immune responses, express CD25, and can release IL-10.

CD8 cytotoxic T cells

T cells that kill infected cells using perforin and granzymes.

MHC class I

Molecules that present antigen specifically to CD8 T cells.

MHC class II

Molecules that present antigen specifically to CD4 T cells.

Professional antigen-presenting cells

Dendritic cells, macrophages, and B cells.

HIV major targets

CD4 T cells and macrophages (with dendritic cells also interacting with HIV).

HIV seroconversion

The development of detectable HIV-specific antibodies following infection.

HAART

Antiretroviral therapy that suppresses viral load and allows CD4 counts to recover, though it does not cure HIV.

CD4 helper T-cell count

The specific cell count tracked to monitor the progression of HIV/AIDS.

gp120

An HIV surface protein that acts as an antibody target.

Neuraminidase

An influenza surface protein targeted by the antiviral drug Tamiflu.

Complement fragments

Cleavage fragments where larger pieces typically bind pathogen surfaces and smaller pieces often promote inflammation.

IgA deficiency

An antibody deficiency that leads to recurrent mucosal infections.