True or false?
1) Antigen-binding sites are located within Fc regions
2) Isolated Fab fragments are produced naturally
3) IgG are dimers
4) In IgE, the Fc part is attached to mast cells and basophils
5) Complement system is activated by IgM and IgG
6) Fc receptors are cell surface proteins, to which Fab fragments are attached
7) Linear epitopes are present on non-denatured proteins
8) Kappa (κ) chain, and lambda (λ) chain are two types of light chain
9) Polyclonal antibodies are produced by hybridomas
10) Immunoglobulins can be either membrane receptors or secreted antibodies
11) Еach B cell is producing immunoglobulin of a single specificity
12) Ig heavy and light chain genes consist of multiple gene segments
13) V(D)J recombination of gene segments is the second step in gene rearrangements
14) Mature lymphocytes are those that completed their development
15) Mature lymphocytes are never naïve cells
16) Affinity maturation is the process by which activated B cells produce antibodies with increased affinity for antigen
17) T cell-independent activation results in production of antibodies with higher affinity
18) Plasmablasts – differentiated B cells that did not go through the second step of differentiation
19) Plasma cells secrete IgM
20) Memory B cells are dormant
21) Breg cells are immunosuppressive
22) T cells mature in the thymus
23) Helper T cells are CD4+
24) Memory T cells are always CD4+
25) TCRs are always membrane-bound
26) TCRs also undergo somatic hypermutation
27) The binding between TCR and antigen peptides is degenerate
28) γδ T cells require MHC presentation of peptide epitopes
29) CD3 is a unique marker of B-lymphocytes
30) All cells are professional antigen-presenting cells
31) MHC molecules mediate interactions of leukocytes with other leukocytes or with body cells
32) The human MHC complex is called the HLA (human leukocyte antigen)
33) CD8+ cytotoxic T cells recognize antigens only within MHC class I molecules
34) MHC II molecules present antigens only from extracellular pathogens
35) MHC I molecules normally occur only on professional antigen-presenting cells
36) β2 microglobulin is necessary for cell surface expression of MHC class I
37) MHC class II can be conditionally expressed by all cell types
38) MHC class II molecules are expressed very early during the development of B cells
39) Bone marrow stromal cells secrete cytokines that regulate development and differentiation
of blood cells and their progenitors
40) Immature B-cells with self-reactive BCR quickly leave bone marrow
41) Receptor editing is one of the mechanisms to prevent formation of B-lymphocytes with self-reactive BCR
42) Only those B cells, whose BCR do not recognize autoantigens, can leave the bone marrow