1: Basophil, 2: Lymphocyte, 3: Basophil, 4: Neutrophil

1: Eosinophil, 2: Lymphocyte, 3: Neutrophil, 4: Basophil

1: Neutrophil, 2: Lymphocyte, 3: Eosinophil, 4: Basophil

1: Neutrophil, 2: Macrophage, 3: Lymphocyte, 4: Basophil

The CD8 molecule

The Major Histocompatibility Complex molecule

The T cell receptor

The B cell receptor

Both the MHC and peptide in the peptide:MHC complex to strengthen the binding between the T cell and antigen presenting cell

The peptide in the peptide:MHC complex to strengthen the signals delivered by the antigen presenting cell

The α1 domain of the MHC class II molecule to strengthen the signals delivered by the antigen presenting cell

The β2 domain of the MHC class II molecule to strengthen the binding between the T cell and antigen presenting cell

1: Eosinophil, 2: Lymphocyte, 3: Neutrophil, 4: Basophil

1: Neutrophil, 2: Lymphocyte, 3: Eosinophil, 4: Basophil

1: Lymphocyte, 2: Basophil, 3: Neutrophil, 4: Eosinophil

1: Basophil, 2: Lymphocyte, 3: Eosinophil, 4: Neutrophil

The release of naïve T cells expressing both CD4 and CD8 is most important.

Thymocytes that fail positive selection are killed by thymic epithelial cells

The affinity of the TCR is only important in positive selection

The majority of developing thymocytes do not become naïve T cells

The virus is degraded into short peptides (8-10 amino acids in length)

The virus is present in the cytosol of the APC

The protein is encoded by viral genes (particularly double-stranded and single-stranded RNA)

The virus is degraded in an acidic vesicular endosome of the APC

The strength of binding of the integrin is increased

The cells accumulate (swarm) to the vessel wall increasing integrin concentration at the site

The number of integrin molecules that cluster on the cell surface is increased

The distance that the integrin extends from the cell surface is increased

1: Basophil, 2: Lymphocyte, 3: Basophil, 4: Neutrophil

1: Neutrophil, 2: Lymphocyte, 3: Eosinophil, 4: Basophil

1: Eosinophil, 2: Lymphocyte, 3: Neutrophil, 4: Macrophage

1: Neutrophil, 2: Macrophage, 3: Lymphocyte, 4: Basophil

The number of variable regions on a TCR and BCR are the same.

The constant region of a TCR and BCR are the same

How the variable regions of a TCR and BCR are generated is the same

The variable region of all T cells is the same

Cross-presentation, whereby infected epithelial cells are phagocytosed by dendritic cells, and the viral proteins originally synthesized in the epithelial cells are processed and presented in class I MHC molecules on the dendritic cell

Cross-talk, whereby viral antigens binding to class I MHC molecules in the epithelial cells cause the secretion of inflammatory cytokines that are able to indirectly activate the naïve CD8⁺ T cell, allowing the activated cell to kill infected cells through the secretion of perforin and granzymes

Cross-talk, whereby viral infection of the epithelial cell stimulates the expression of surface molecules that are typically found only on dendritic cells, this allows the epithelial cells to 'talk' to, and activate, naïve CD4⁺ and CD8⁺ T cells

Cross-presentation, whereby viral antigens are expressed in MHC class I molecules that then 'feed' those viral antigens to dendritic cells, these are then able to process and present these antigens in MHC class II molecules for presentation and activation of CD4⁺ T cells