2 - Cells of the Immune System Flashcards
Which interleukin stimulates the lymphoid line development in bone marrow?
IL-7
Citokines needed to development of myeloid line in bone marrow
GM-CSF, IL-3
Which cytokine participate in eosinophils development in the bone marrow?
IL-5
Which cytokine is needed to stimulate the production of platelets from megakaryocytes?
IL-11
What is the unique process in the formation of the B cell antigen receptor?
Somatic hypermutation
*causes affinity maturation, during the clonal burst of proliferation of a B lymphocyte in response to antigen.
How is the variable portion of the heavy chain of BCR and the Beta chain of TCR formed?
Combination of 3 gene segments: V,D,J
What is the function of the CD19, 20 in signal transduction of the BCR?
Lower threshold for the antigen (less Ag is needed to activate)
What is the effect of the CD3 signal transduction through the TCR?
Cell proliferation
Cytokine production
*allow more protein kinase binding
What is the function of the Tdt enzyme?
Add nucleotides between V,D,J segments of heavy chain (Ig) and Alfa, beta (all) chains of TCR ▶️ more variability
*no active for light chain of Ig, after it has been rearranged
Who is in charge of the rearrangement of the variable domains of BCR and TCR? Genes and protein.
RAG1, RAG2 genes
Recombinase protein
*maturation of lymphocytes
Missense and null mutation of RAG genes? Diseases, mechanisms and presentation.
- missense: Ommen syndrome ▶️ rag enzymes partial activity ▶️ ⬇️ B, T cells, early onset failure to thrive, red rash, diarrhea, severe immunodeficiency
- null: Severe combined immunodeficiency (SCID) ▶️ no rag enzyme activity ▶️ total lack B, T cells, total defect in humoral and cellular immunity
Which population of cells express Tdt?
Early B-cells precursors (lymphoblasts)
*mature B-cell stage (IgM at surface or cytoplasm) doesn’t express Tdt
