Mnemonics: T Lymphocytes

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU

Th
I
Infection
Intracellular pathogens
Immune diseases, i.e. autoimmune diseases
Inflammatory bowel disease (IBD)

Th2
Antibodies, i.e. humoral immunity
Allergy
Asthma
Allergic rhinitis

The mnemonic for different T-cell subtypes is FERMNN G ("pheromon G"):

Four, CD4, helper cells (Th1 and Th2)
Eight, CD8, killer cells
Regulatory, formerly known as suppressors
Memory
Naïve T cells
Natural Killer T cells (NKT)

Gamma/delta T cells (γδ)

CDs on Different Cells

T cells have CD 3, 4 and 8 (double, 4 x 2)
B cells have CD 19, 20 and 40 (double 20 x 2)

There are 3 types of interferons -- ABG:
Alpha, IFN-α
Beta, IFN-β
Gamma, IFN-γ

IFN
α
αlba (white blood cells)

IFN-β
fibroβlasts

Interleukins: Hot T-Bone stEAk

IL-1: fever (Hot)
IL-2: stimulates T cells
IL-3: stimulates Bone marrow
IL-4: stimulates IgE
IL-5: stimulates IgA

MHC

MHC class II molecules bind to CD4+/CD8- T cells. MHC class I molecules bind to CD8+/CD4- T cells. This relationship is remembered by the mnemonic 2 x 4=8 and 1 X 8 = 8, the final result is always 8, 2 is MHC II, 1 is MHC II, 4 is CD4, 8 is CD8.

MHC numbers: 2, 4, 8, 16

MHC2 x CD4 = 8 - MHC2 binds best 16 amino acid-long peptides (11-30)

MHC1 x CD8 = 8 - MHC2 binds best 8 amino acid-long peptides (8-10)

Transduction pathways

ITAM
Activates transduction pathways

ITIM
Inhibits transduction pathways

3 sequential Ts:
Transduction - MHC and TCR, CD28-CD80/86
Transcription - nuclear factors - NFkB
Translation - IL-2

MHC Genes

MHC I - genes ABC
MHC II - genes D, again alphabetical - DP, DQ, DR
Both on chromosome 6

I......II
ABCD PQR

MHC

I
1 letter HLA: ABC
1 polypeptide chain MHC (alpha and beta-2 microgobulin)

II
2 letters HLA: DP, DQ, DR
2 polypeptide chains MHC (alpha and beta)

Surface Markers

L
Ligands on
Lymphocytes

CD40L on T helpers (CD4+)
FAS-L on CTL 9CD8+)

CD40 on B cells
FAS ("death signal") on cells to be killed by CTLs

ZAP70

ZAP 70 binds to the Zeta chain (CD247) of the T-cell receptor.

Z
ZAP-70
Zeta-chain-associated protein kinase 70 (70 is the molecular weight in kDa)

ZAP70 deficiency is a form of SCID (T-/B+/NK+), one of the few SCID forms with palpable LN. ZAP-70 deficiency is a form of SCID with no CD8 cells and no T cell function, but with normal B and NK cells.


T-cell receptor complex with TCR-α and TCR-β chains. Image source: Wikipedia.

This video describes the process by which apoptosis is activated by T cells. This video is from: Janeway's Immunobiology, 7th Edition Murphy, Travers, & Walport. Source: Garland Science. Severe combined immunodeficiency (SCID) - 4 groups according to T/B/NK cells (click to enlarge the image). Discovery of T-cell Receptors (video) National Jewish Health scientists John Kappler, PhD, and Philippa Marrack, PhD, discuss their discovery of the T-cell receptor - the protein found on the surface of T Cells that helps detect specific antigens, or foreign invaders, in the body:
Published: 01/24/2008
Updated: 08/03/2012