**5. Induction of lipid droplet biogenesis**

**Gene Protein**

*Rv3130c* (*tgs1*) DGAT + +

42 Tuberculosis - Current Issues in Diagnosis and Management

*Rv3804c* (*85A*) DGAT + NA

*BCG1489c* [*Rv1428c*] DGAT NA +

*BCG1489c* [*Rv1428c*] acyltransferase NA +

*Rv3097c* (*lipY*) Lipase/esterase + NA

*BCG3153c* (*tgs1*) [*Rv3130c*]

*BCG3794c* (*tgs2*) [*Rv3734c*]

**Gene Protein**

*Rv0183* Lipase/esterase

**Gene Protein**

DGAT, diacylglycerol acyltransferase

*Rv0467* (*icl*), *Rv1915-1916* (*icl2*) **DGAT activity** *(in vitro)*

DGAT NA +

DGAT NA +

**TGAhydrolyzing activity (***in vitro***)**

Hydrolyzes only monoacylglyceri des

*Rv2224c* Lipase/esterase NA NA NA

**Isocitrate cleavage (***in vitro***)**

**Lipid body associated**

**Lipid body associated**

isocitrate lyase + NA NA

**Lipid body associated** **Influence on lipid bodies / TGA accumulation**

Δ*tgs1* decreases TAG accumulation

Overexpression increases production of lipid bodies

Δ*BCG1489c* reduces TAG accumulation

Δ*BCG3153c* reduces TAG accumulation

Δ*BCG3794c* reduces TAG accumulation

Δ*Rv1428c* reduces TAG accumulation

**Influence on lipid bodies / TGA accumulation**

Δ*lipY* reduces TAG hydrolysis. Overexpression increases TAG hydrolysis

**Influence on lipid bodies / TGA accumulation**

**Table 1.** Enzymes involved in lipid body metabolism in *M. tuberculosis* and *M. bovis* BCG. Homologous genes in *M. tuberculosis* H37Rv are written in square brackets. NA, not applicable. \*, expressed in yeast as recombinant protein.

*Rv1399c* (*lipH* ) Lipase/esterase + NA NA NA ML0314c (*lipU)* [72] *BCG1721* [*Rv1683*] Lipase/esterase + (in vivo\*) + + (\*) NA ML1346 [69]

*Rv3734c* (*tgs2*) DGAT + + NA NA ML1244 [48,68] *Rv3234c* (*tgs3*) DGAT + NA NA NA ML1244 [48,68] *Rv3088* (*tgs4*) DGAT + NA NA NA ML1244 [48,68] *Rv1760* DGAT + NA NA NA ML1244 [48,68] *Rv2285* DGAT + NA NA NA ML1244 [48,68]

**Modulation of virulence**

**Modulation of virulence**

Overexpression increases virulence in mice

NA NA NA ML2603 [76]

Gene disruption decreases virulence in mice

> **Modulation of virulence**

The Δ*icl* , Δ*icl2* strain shows no intracellular replication

*M. leprae homologue*

NA ML1244 [46,48,68]

NA ML0097 (85A) [71]

NA ML2427c [69]

NA ML1244 [69]

NA ML1244 [69]

NA [69]

*M. leprae* **homologue**

ML0314c (*lipU*) ML1053 ML1183c

ML1633c [77]

ML1985c (aceA) [79,80,93-95]

*M. leprae* **homologue** **Reference**

[47]

**Reference**

**Reference**

Since the biogenesis of lipid droplets in macrophages seems an absolute requirement for intracellular bacteria to establish infections, we will discuss mechanisms involved in foam cell formation and development of lipid droplets.
