Gene Symbol: TIMD4
Full Name: T Cell Immunoglobulin and Mucin Domain Containing 4
Chromosomal Location: 5q33.3
NCBI Gene ID: [10578](https://www.ncbi.nlm.nih.gov/gene/10578)
OMIM: [610131](https://www.omim.org/entry/610131)
Ensembl ID: ENSG00000134030
UniProt: [Q9C0J8](https://www.uniprot.org/uniprot/Q9C0J8)
Function
The TIMD4 gene encodes TIM-4 (T-cell immunoglobulin and mucin domain-containing protein 4), a phosphatidylserine receptor that plays a critical role in the recognition and engulfment of apoptotic cells [@tim]. TIMD4 is primarily expressed on macrophages, dendritic cells, and [microglia](/cell-types/microglia-neuroinflammation) in the brain [@microglial].
Phosphatidylserine Recognition
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TIMD4 Gene (T Cell Immunoglobulin and Mucin Domain Containing 4)
Gene Symbol: TIMD4
Full Name: T Cell Immunoglobulin and Mucin Domain Containing 4
Chromosomal Location: 5q33.3
NCBI Gene ID: [10578](https://www.ncbi.nlm.nih.gov/gene/10578)
OMIM: [610131](https://www.omim.org/entry/610131)
Ensembl ID: ENSG00000134030
UniProt: [Q9C0J8](https://www.uniprot.org/uniprot/Q9C0J8)
Function
The TIMD4 gene encodes TIM-4 (T-cell immunoglobulin and mucin domain-containing protein 4), a phosphatidylserine receptor that plays a critical role in the recognition and engulfment of apoptotic cells [@tim]. TIMD4 is primarily expressed on macrophages, dendritic cells, and [microglia](/cell-types/microglia-neuroinflammation) in the brain [@microglial].
Phosphatidylserine Recognition
TIMD4 binds specifically to phosphatidylserine (PS) exposed on the surface of apoptotic cells. This recognition mechanism is essential for:
Apoptotic Cell Clearance: TIMD4 mediates the engulfment of dying cells, preventing the release of intracellular contents that could trigger inflammatory responses [@phosphatidylserine]
Immune Tolerance: Proper clearance of apoptotic cells by TIMD4-expressing phagocytes prevents autoimmunity
Resolution of Inflammation: TIMD4 contributes to the anti-inflammatory environment during tissue repair
Microglial Function
In the central nervous system, TIMD4 is expressed on microglia, the resident immune cells of the brain. Microglial TIMD4 plays important roles in:
Synaptic Pruning: During development, microglia use TIMD4 to recognize and eliminate excess synapses
Neuroinflammation: TIMD4-mediated clearance of apoptotic [neurons](/entities/neurons) may influence neuroinflammatory processes in neurodegenerative diseases
Role in Neurodegenerative Diseases
Alzheimer's Disease
TIMD4 has been implicated in Alzheimer's disease pathogenesis through several mechanisms:
Microglial Activation: TIMD4 expression on microglia is altered in Alzheimer's disease brains, affecting the clearance of [amyloid-beta](/proteins/amyloid-beta) plaques and apoptotic neurons [@tima]
Neuroinflammation: Dysregulated TIMD4 function may contribute to chronic neuroinflammation, a key feature of AD
Phagocytic Clearance: Impaired TIMD4-mediated clearance of amyloid-beta may lead to plaque accumulation [@amyloidbeta]
Parkinson's Disease
In Parkinson's disease, TIMD4 may play roles in:
Dopaminergic Neuron Survival: TIMD4-mediated clearance of dead dopaminergic neurons in the substantia nigra
[Alpha-Synuclein](/proteins/alpha-synuclein) Clearance: Microglial phagocytosis of alpha-synuclein aggregates may involve TIMD4
Neuroinflammation: TIMD4 contributes to microglial responses in PD [@microgliala]
Amyotrophic Lateral Sclerosis
TIMD4 has been studied in ALS context:
Motor Neuron Degeneration: TIMD4-mediated clearance of dying motor neurons
Glial Activation: TIMD4 expression on [astrocytes](/entities/astrocytes) and microglia in ALS models [@timb]
Expression Patterns
TIMD4 exhibits tissue-specific expression:
Brain: Expressed on microglia, particularly in regions with high neuronal density
Immune System: High expression on macrophages, dendritic cells, and splenic marginal zone macrophages
Peripheral Tissues: Moderate expression in liver, lung, and intestinal tissues
Expression is modulated by inflammatory cytokines and neuronal activity.
Therapeutic Implications
TIMD4 represents a potential therapeutic target for neurodegenerative diseases:
Modulation of Microglial Phagocytosis: Enhancing TIMD4 function could improve clearance of pathological protein aggregates
Anti-inflammatory Strategies: TIMD4-based therapies could reduce harmful neuroinflammation
Drug Development: Small molecules targeting TIMD4-PS interaction are being investigated
Genetic Associations
TIMD4 polymorphisms have been associated with autoimmune diseases
Gene expression studies show altered TIMD4 levels in neurodegenerative disease brains
TIMD4 is part of a gene network involving immune response and phagocytosis genes
Clinical Significance
Understanding TIMD4 function has clinical relevance for:
Biomarker Development: TIMD4 expression levels as a marker of microglial activation
Therapeutic Targeting: Developing modulators of TIMD4 function
Disease Monitoring: TIMD4 in cerebrospinal fluid as a potential biomarker
See Also
[TIM (T-cell Immunoglobulin and Mucin Domain) Family](/mechanisms/tim-family) - TIMD4 belongs to this protein family
[Macrophage](/cell-types/macrophages) - TIMD4 expressed on macrophage surfaces
[Alzheimer's Disease](/diseases/alzheimers-disease) - Immune response in neurodegeneration