Immunology — Flashcards

Flashcard 71: _____ are exotoxins that cause a massive amount of T-cell activation

Answer: Superantigens

Flashcard 72: The antigen receptors of T lymphocytes have one _____ and beta chain (monovalent)

Answer: alpha

Flashcard 73: _____ Lymphoid Cell Function B & T cells - Found in bloodstream, lymph nodes, spleen, submucosa, and epithelia B cells: contain markers CD19, CD20, CD21 - Mature into plasma cells - Function is to produce antibodies TH cells: contain markers CD3 and CD4 - Function is to regulate immune responses Cytotoxic T cells: contain markers CD3 and CD8 - Function is to kill infected cells NK cells - Contain markers CD16 and CD56 - Function is to kill tumor/virus cell targets or antibody-coated target cells - T cells can only bind peptides that have been processed and presented by major histocompatibility complexes (MHCs)

Answer: Basic

Flashcard 74: V(D)J recombination in heavy chains begins with _____ joining, followed by V-D/J joining

Answer: D-J

Flashcard 75: _____ T cells migrate preferentially to respiratory organs, skin, and peritoneal cavity

Answer: Gamma-delta

Flashcard 76: Which T-helper cells are active against extracellular bacteria and fungi?_____

Answer: Th17

Flashcard 77: Which antibodies serve as recognition receptors for antigens on naive B cells?

Answer: IgM and IgD

Extra: Surface IgM and IgD serve as the B-cell receptors (BCR) on naive B cells for antigen recognition.

Flashcard 78: Which antibody is mainly responsible for precipitation?_____

Answer: IgG

Flashcard 79: Which type of TCR recognizes antigens without the requirement of MHC?

Answer: γδ (Gamma-delta) T cells

Extra: Most T cells are αβ T cells which require MHC-restricted antigen presentation. In contrast, γδ T cells (Gamma-delta T cells) can recognize antigens (including non-peptide antigens like lipids and phosphoantigens) directly without the requirement for MHC molecules.

Flashcard 80: An immune ring (Wesseley) may be seen around the fungal  ulcer due to deposition of the _____

Answer: immune complexes