GO Content Meeting November 15 and 16, 2005 Improving the Representation of Immunology in the Gene Ontology

GO Content MeetingNovember 15 and 16, 2005

Improving the Representation of

Immunology in the Gene Ontology

Proposal List for GO Content Meeting

A. Self and Non-Self Processes

B. Reorganization of Cytokine Function Terms

C. Adding CD antigen binding terms

D. Improvements to T cell differentiation hierarchy

E. Reorganization of immune response terms in several ways 1) Activation of the immune system vs. effector mechanisms 2) Improving representation of innate immunity 3) Improving representation of immune cell differentiation 4) Improving GO:0006954 inflammatory response

F. The problem of regulation terms under immune response

G. Tumor surveillance terms


A. Self and Non-Self Processes – Amelia and Jane







































Problems for Immunology in the GO

Incomplete Representation of Immunological Processes

Conceptual Problems in Term Organization

Poorly Formulated and Poorly Defined Terms

Incomplete Representation of Immunological Processes Current GO lacks whole groups of terms for processes such as

mucosal immunitytolerance inductionB cell differentiation

And individual terms for important processes such asgranuloma formationgerminal center formationaffinity maturation

Conceptual Problems in Immunology Term Organization in the GO

Terms describing the development of immune system components are incorrectly placed under GO:0006955 immune response, when in fact many of the differentiation steps occur prior to an immune response.

T cell differentiation (T cell development)B cell differentiation (B cell development)

Conceptual Problems in Immunology Term Organization in the GO (2)

The GO terms for cytokine metabolism and cytokine production are children of immune response, when in fact many cytokines are produced independently of immune responses and have non-immunological functions (EGF or TGF-ß, for example).


Separate GO terms for antigen processing and antigen presentation exist, without recognition of the relationship of these two concepts. Furthermore, the children of these terms are not well defined and important subprocesses are missing from the GO. This has led to confusion by annotators in the use of these terms, and reflects poorly on the GO.


GO:0006955 immune response is a child of defense response in the current GO, yet immune responses include tolerance induction and regulatory processes that are not defense responses.

GO:0006954 inflammatory response is a child of immune response, yet inflammatory responses include non-immunological components.

Poorly Formulated and Poorly Defined Termshumoral immune response ; GO:0006959

--% humoral defense mechanism (sensu Vertebrata) ; GO:0016064

--% humoral defense mechanism (sensu Protostomia) ; GO:0016065




An immune response mediated through a body fluid.




The specific immune response mediated by antibodies, as in, but not restricted to, the vertebrates (Vertebrata, ncbi_taxonomy_id:7742).




The specific immune response mediated by antibodies. As in, but not restricted to, the taxon Protostomia (Protostomia, ncbi_taxonomy_id:33317).

The Big Picture

The Big Picture

Assumptions Behind Changes to Immune Response DAG

Current definition of GO:0006955 immune response:

Any process involved in the immunological reaction of an organism to an immunogenic stimulus.


1. Immunological reactions involve largely, but not solely, hematopoietically derived cell types, commonly referred to as immune cells or leukocytes in the GO, and may target any tissue or cell type in the body as well as infecting organisms.


2. An “immunological stimulus” is any stimulus capable of activating an immune response activating cell surface receptor pathway. Such pathways include:

BCR and TCR signaling pathways on mature B and T cellsC-type lectin receptor signaling pathways with activation activitiesKIR signaling pathways with activation activitiesFc receptor signaling pathways with cellular activation activitiesToll-like receptor signaling pathways (and Toll in drosophila)complement receptor signaling pathways with activation activitiescertain other pathways (scavenger receptors etc.)


3. An immune response is considered to be the set of physiological processes carried out by immune cell types and certain additional cell types following an immunological stimulus. Differentiation processes for immune cell types (for instance thymic T cell development) prior to an immunogenic stimulus are not considered part of the immune response.


4. An immune response may be made against both self and non-self determinants. Although the GO is intended to cover "normal" processes, these processes include immune responses against microbes, pests and parasites of all types, whether pathogenic or not, tolerance induction mechanisms against peripheral antigens whether of self or non-self origin, anti-tumor immune responses, and even beneficial autoimmune responses.

Changes to the GO:0006955 immune response hierarchy

Multiple Modes of Immune Response

1. Innate Immune Response

2. Adaptive Immune Response

3. Humoral Immune Response

4. Mucosal Immune Response

Changes to the GO:0006955 immune response hierarchy

Innate Immune Response

Adaptive Immune Response

Humoral Immune Response

Mucosal Immune Response

Activation of the Immune Response

Immune Effector Process

Immune Cell Mediated Immunity

Regulation of Immune Response

Problems with Regulation

GO dogma: positive regulation of a child term is a type of positive regulation of a parent term.

However, this inference is not strictly true for many processes in the immune system.




Inflammatory Response

Tolerance Induction

Cell Activation

The current paradigm in the biological_process ontology is that T cell and B cell differentiation and proliferation are types of T cell and B cell activation, respectively. This DAG structure has certain advantages in annotation of things like T cell proliferation assays.

T cell and B cell activation are defined in the GO to include any type of activation of those cell types, not just activation through the TCR or BCR, and included implicitly in activation are activation steps required for differentiation.

The big change now is that T and B cell differentiation processes prior to an immune response (what immunologists know as T cell development and B cell development) are no longer children of GO:0006955 immune response.

Somatic Diversification of Immune Receptors

Immunoglobulin Production

Outstanding Questions

1. What other pathways of activation constitute immunological stimuli?

2. How should inhibitory pathways (ITIMs) be handled?

3. Should plant innate immunity be included under innate immunity?

4. What other pathways of innate immunity, particularly for invertebrates should be included?

Outstanding Questions

5. What is the proper relationship of the inflammatory response to the immune response?

6. Is the cell activation/differentiation/proliferation structure the best way to show the relationships of these terms?

7. Is central tolerance to non-self antigens via upregulation of CD4+CD25+ T regulatory cell differentiation an immune response or not?

Documents

GO Content Meeting November 15 and 16, 2005 Improving the Representation of Immunology in the Gene Ontology