The initiation of the activity of the inactive enzyme MAP kinase (MAPK).

An immune response mediated by cells expressing specific receptors for antigen produced through a somatic diversification process, and allowing for an enhanced secondary response to subsequent exposures to the same antigen (immunological memory).

The process in which B cells produce antibodies with increased antigen affinity. This is accomplished by somatic hypermutation and selection for B cells which produce higher affinity antibodies to antigen.

An immune response dependent upon secreted immunoglobulin. An example of this process is found in Mus musculus.

Any process that modulates the frequency, rate, or extent of immunoglobulin production.

An immune response mediated by immunoglobulins, whether cell-bound or in solution.

An immune response against bacteria mediated through a body fluid. Examples of this process are the antibacterial humoral responses in Mus musculus and Drosophila melanogaster.

The process in which an antigen-presenting cell expresses antigen (peptide or lipid) on its cell surface in association with an MHC protein complex.

Any process that modulates the frequency, rate or extent of cell morphogenesis. Cell morphogenesis is the developmental process in which the shape of a cell is generated and organized.

Any process that activates or increases the rate or extent of B cell proliferation.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the MAPK cascade.

The directed movement of substances, in membrane-bounded vesicles, from the early sorting endosomes to the late sorting endosomes; transport occurs along microtubules and can be experimentally blocked with microtubule-depolymerizing drugs.

Innate immune responses are defense responses mediated by germline encoded components that directly recognize components of potential pathogens.

Any process that activates or increases the frequency, rate or extent of endocytosis.

Any process that activates or increases the frequency, rate or extent of the phosphorylation of peptidyl-tyrosine.

Any process that activates or increases the frequency, rate or extent of the immune response, the immunological reaction of an organism to an immunogenic stimulus.

Reactions triggered in response to the presence of a Gram-negative bacterium that act to protect the cell or organism.

Reactions triggered in response to the presence of a Gram-negative bacterium that act to protect the cell or organism.

A series of molecular signals initiated by the cross-linking of an antigen receptor on a B cell.

Any process that activates or increases the frequency, rate or extent of B cell activation.

The movement of a leukocyte within or between different tissues and organs of the body.

That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

The external part of the cell wall and/or plasma membrane.

That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.

The leaflet of the plasma membrane that faces away from the cytoplasm and any proteins embedded or anchored in it or attached to its surface.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

An immunoglobulin complex that is present in the plasma membrane of B cells and that in its canonical form is composed of two identical immunoglobulin heavy chains and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.

An immunoglobulin complex that is secreted into extracellular space and found in mucosal areas or other tissues or circulating in the blood or lymph. In its canonical form, a circulating immunoglobulin complex is composed of two identical heavy chains and two identical light chains, held together by disulfide bonds. Some forms of are polymers of the basic structure and contain additional components such as J-chain and the secretory component.

Cytoplasm situated near, or occurring around, the nucleus.

A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm.

A circulating form of IgM consisting of a pentamer of IgM core units with a single J chain polypeptide.

A circulating form of IgM consisting of a hexamer of IgM core units with a single J chain polypeptide.

A phospholipid microvesicle that is derived from any of several cell types, such as platelets, blood cells, endothelial cells, or others, and contains membrane receptors as well as other proteins characteristic of the parental cell. Microparticles are heterogeneous in size, and are characterized as microvesicles free of nucleic acids.