Immunology Quiz: Cells and Processes

Immune System

• The cells responsible for releasing histamine in allergic conditions are mast cells.
• Chemotaxis is the term referring to the movement of leukocytes towards bacteria.
• Phagocytosis is the process by which macrophages and granulocytes ingest microorganisms.
• The reverse transcriptase of the HIV virus transcribes viral RNA into DNA.

Immune Response

• Opsonins are products of the immune system, including Class II MHC products, IgG, and C3b.
• Leukocytes use oxidative activity to kill pathogenic organisms.
• Integrases are viral enzymes that assist in the integration of the HIV provirus into the cellular genome.
• The C3b component of complement is an opsonin because phagocytes recognize it with their receptors.

Immune Cells

• Macrophages possess a receptor for the Fc fragment of IgG.
• Mast cells express a receptor for the Fc fragment of IgE.
• Eosinophils mature in the presence of IL-5.
• B lymphocytes in humans mature in the bone marrow.
• T lymphocytes mature in the thymus.

Immunoglobulins

• IgM appears before IgG in the primary immune response because its production does not require antigen.
• In the secondary immune response, antibody production begins earlier, and IgG concentrations are higher.
• Cell-mediated immunity can be transferred to a non-immune individual by the transfer of T lymphocytes.
• The first immunoglobulin chain synthesized during B lymphocyte maturation is the μ heavy chain.

MHC and Antigen Presentation

• Human Class II MHC products include HLA-DR, HLA-DP, and HLA-DQ.
• Antigen processing is possible in macrophages and other antigen-presenting cells.
• Coreceptor molecules on the membrane of T lymphocytes are CD4 and CD8 molecules.

Immune Response Regulation

• The activation of the complement system via the alternative pathway does not involve C1, C2, and C4.
• If autoreactive cells are not eliminated by negative selection in the thymus, it will lead to autoimmune diseases.
• The function of B lymphocytes is not cytotoxicity.

Immune System Disorders

• In Myasthenia gravis, there are autoantibodies specific for the acetylcholine receptor.
• The presence of the HLA-B27 allele does not represent an increased risk for the development of type I insulin-dependent diabetes mellitus.
• Patients with DiGeorge syndrome lack a thymus and therefore suffer from T cell deficiencies.

Antibody Structure and Function

• The Fab fragment of an antibody does not include the C-terminus of the heavy chain.
• The primary functions of the Fc fragment of an antibody include passage of antibodies through the placenta, binding to mast cells and basophils, and complement activation.

Transplantation and Immunotherapy

• Immunosuppressive therapy is applied in autoimmune diseases and organ transplantation.
• Adoptive immunotherapy of malignant diseases involves the use of LAK cells, which are generated in vitro by high doses of IL-2 acting on NK cells.
• Cytotoxic CD8+ T lymphocytes recognize tumor antigens in the context of Class I MHC molecules.
• Macrophages can induce apoptosis of malignant cells by producing TNF-α and oxygen free radicals.
• TAMs (tumor-associated macrophages) can induce tumor neovascularization.