Vaccination

Vector-borne infections

Original antigenic sin

Immunogens

Correlates of immune protection

Vaccine

Active immunity

Herd immunity

Sterilizing immunity

Toxoids

Adjuvant

Antigenic drift

Antigenic shift

Primary immunodeficiency

Secondary immunodeficiency

Combined immunodeficiencies (CIDs)

Severe combined immunodeficiency (SCID)

Agammaglobulinemia

Human immunodeficiency virus (HIV)

Acquired immunodeficiency syndrome (AIDS)

Retrovirus

Reverse transcriptase (RT)

Seroconversion

Antiretroviral therapy (ART)

Tolerance

Negative selection

Regulatory T (TREG) cells

Tolerogens

Immunogens

Anergy

Immunomodulatory

Molecular mimicry

Alloreactivity

Autograft

Isograft

Allograft

Xenograft

Histocompatible

Graft-versus-host disease (GvHD)

Tissue typing

Cross-matching

Hyperacute rejection

Acute rejection

Chronic rejection

Malignant

Metastasis

Transformation

Proto-oncogene

Oncogenes

Tumor-suppressor genes

Tumor-specific antigens (TSAs)

Tumor-associated antigens (TAAs)

Immunoediting

Immunotherapy

Adjuvant cancer therapy

Neoadjuvant cancer therapies

Neoantigens

Checkpoint blockade

CARs (CAR T cells)

Thymic cortex

Thymic medulla

Double-negative (DN) thymocytes

Pre-T-cell receptor (pre-TCR)

Double-positive (DP) thymocytes

MHC restriction

Self-tolerance

Positive selection

Negative selection

Apoptosis

Affinity model of selection

Single-positive (SP) thymocytes

Cortical thymic epithelial cells (cTECs)

Medullary thymic epithelial cells (mTECs)

Lineage commitment

Regulatory T cells (TREG cells)

Naïve T cells

Two-signal hypothesis

Avidity

Anergy

Costimulatory receptors

Coinhibitory receptors

CD28

Programmed cell death protein-1 (PD-1 or CD279)

Polarizing cytokines

Type 1 responses

Type 2 responses

Adjuvants

Master gene regulator

Effector cytokines

T helper type 1 (TH1) cells

T helper type 2 (TH2) cells

T helper type 17 (TH17) cells

Peripheral TREG (pTREG) cells

T follicular helper (TFH) cells

T helper type 9 (TH9) cells

Central memory T cells (TCM)

Degranulation

Neutralization

Agglutination

Opsonization

Antibody-dependent cellular phagocytosis (ADCP)

Poly-Ig receptor (polyIgR)

Fc receptors (FcRs)

Neonatal Fc receptor (FcRn)

Cytotoxic T lymphocytes (TC cell or CTLs)

CTL precursors (CTL-Ps)

MHC tetramers

Perforin

Granzymes

Natural killer (NK) cell

Missing self model

Balanced signals model

NK receptors

KIR

Ly49

NKT cell

MHC locus

MHC class I molecules

MHC class II molecules

Antigen-presenting cells (APCs)

Antigen processing

Antigen presentation

β2-Microglobulin

Anchor residues

Histocompatibility antigens

Human leukocyte antigen (HLA) complex

H2 complex

Polymorphic

Haplotype

Codominant

Polygenic

Professional antigen-presenting cells (pAPCs)

Endogenous pathway (of antigen processing/presentation)

Exogenous pathway (of antigen processing/presentation)

Immunoproteasome

TAP (transporter associated with antigen processing)

Invariant chain (Ii)

Cross-presentation

Delayed-type hypersensitivity (DTH)

Types I, II, III, and IV hypersensitivity

Allergy

Chronic inflammation

Atopy

FcεRI receptor

FcεRII receptor

Degranulation

Histamine

Leukotrienes and prostaglandins

Atopic (allergic) march

Anaphylaxis

Hygiene hypothesis

Desensitization

Q: How many different MHC II molecules does each one of you have (assuming you are heterozygous for each MHC allele and your parents have different MHC alleles)?

A: 12 MHC II molecules

Thank You!

Answer:

The reason why there are so many more combinations for MHC 2 is because each MHC2 molecule has two chains (alpha and beta) encoded by two separate genes in the MHC locus, and new combinations can be made between the alpha chain from one parent and the beta chain from the other parent. Please, see the following example:

MHC2 genes from the father:

DP1a, DP1b, DQ1a, DQ1b, DR1a, DR1b

MHC2 genes from the mother:

DP2a, DP2b, DQ2a, DQ2b, DR2a, DR2b

Molecules expressed on the surface of the APCs in the offspring:

From the father –

DP1 (DP1a + DP1b),

DQ1 (DQ1a + DQ1b),

DR1 (DR1a + DR1b)

From the mother –

DP2 (DP2a + DP2b),

DQ2 (DQ2a + DQ2b),

DR2 (DR2a + DR2b)

Newly formed

DP1a + DP2b

DP2a + DP1b

DQ1a + DQ2b

DQ2a + DQ1b

DR1a + DR2b

DR2a + DR1b

Altogether 12 different MHC2 molecules.

• Bone marrow
• Thymus

• Lymph nodes
• Spleen
• mucosa-associated lymphoid tissues (MALT)