CX₃CR1 positive cells contribute to formation of microvessels (MV) in Matrigel and deficiency of CX₃CR1 results in leaky MV phenotype.

<p>500 µl of Matrigel subcutaneously implanted in CX₃CR1^+/gfp and CX₃CR1^gfp/gfp mice for 4 weeks. A, Representative sections of Matrigel isolated from CX₃CR1^+/gfp and CX₃CR1^gfp/gfp mice, intravitally stained with lectin (Rhodamine <i>Griffonia Simplicifolia</i>; Red) to show functional MV and DAPI (Nucleus; Blue) show presence of CX₃CR1 (GFP) positive MV. B, Deficiency of CX₃CR1 restricted CX₃CR1 cells to mostly the perivascular region of functional MV within Matrigel. Moreover, the number of integrated vascular associated CX3CR1 positive MV were significantly higher in Matrigels isolated from CX₃CR1^+/gfp mice compared to Matrigels isolated from CX₃CR1^gfp/gfp mice. Data is expressed as mean ± SEM of 25 Matrigel sections/mice (n = 3 independently performed experiments). C, Three dimensional reconstruction of the confocal images using IMARIS indicate CX₃CR1 positive cells integrated into periluminal vascular wall in the Matrigel implanted in CX₃CR1^+/gfp but not in CX₃CR1^gfp/gfp mice where cells remained in perivascular region (Scale bar: 10 µm). Microvessels formed in Matrigels isolated from CX₃CR1^gfp/gfp mice were leaky, which was evident by increased heme content (D & E), Evan's blue dye leak (F & G), and extravasated platelets (CD42b; Red) (H & I) in the matrix compared to Matrigels implanted in CX₃CR1^+/gfp mice. Data is represented as mean ± SEM of 8 Matrigels/group and 10 Matrigel sections/mice (n = 4 independently performed experiments); * denotes p<0.05.