Organ and Bone Marrow Transplant Immunology

These flashcards cover key vocabulary related to organ and bone marrow transplants, immunology, and the mechanisms involved in the immune response.

HLA

Human Leukocyte Antigen, a set of genes that encode for proteins on cell surfaces that help the immune system recognize foreign substances.

MHC Class I

Major Histocompatibility Complex Class I, which presents antigenic peptides to CD8+ T cells.

MHC Class II

Major Histocompatibility Complex Class II, which presents processed antigens to CD4+ T cells.

Invariant Chain

A protein that assists in the transport and presentation of peptide antigens in MHC Class II molecules.

Natural Killer Cells

A type of lymphocyte that recognizes and destroys infected or cancerous cells.

Peptide Loading

The process where peptides are loaded onto MHC molecules for presentation to T cells.

Allelic Exclusion

The mechanism by which only one allele of a gene is expressed while the other allele is silenced, ensuring B cells produce a single receptor type.

Clonal Expansion

The process by which a B or T cell proliferates to form a population of identical cells that recognize the same antigen.

Negative Selection

A process during B cell development that eliminates B cells that react strongly with self-antigens to prevent autoimmunity.

Somatic Recombination

The process by which B and T cell receptors are generated through rearrangement of gene segments.

TCR

T Cell Receptor, responsible for recognizing antigens presented by MHC molecules.

Surrogate Light Chain

A protein that temporarily associates with the heavy chain during the pre-B cell stage to check if it functions correctly.

IgM

Immunoglobulin M, the first antibody isotype produced during the immune response.

HLA DR

A type of MHC Class II molecule that presents antigens specifically to CD4+ T cells.

Cross-Presentation

A process where MHC Class I molecules present exogenous antigens to CD8+ T cells.

Cytokines

Signaling proteins that mediate and regulate immunity, inflammation, and hematopoiesis.

Immature B Cell

A B cell that has completed heavy and light chain rearrangement but has not yet fully matured.