Abstract Details

Title Impact of LAMA5 Variants on Immune Cell Infiltration Using 2D Blood Brain Barrier Culture Model of Multiple Sclerosis

Topic Multiple Sclerosis

Presentation(s) P2 - Poster Session 2 (11:45 AM-12:45 PM)

Poster/Presentation
Number 18-004

Objective

To investigate the impact of LAMA5 variants identified in multiple sclerosis (MS) families on immune cell infiltration across the blood–brain barrier (BBB) using a 2D in vitro co-culture model.

Background

Disruption of BBB integrity plays a central role in MS pathogenesis by facilitating peripheral immune cell entry into the central nervous system, leading to neuroinflammation and neurodegeneration. Laminin subunit alpha-5 (LAMA5), a key extracellular matrix component of the BBB, has been implicated in regulating endothelial–immune cell interactions. Variants in LAMA5 may therefore alter adhesion molecule expression and promote lymphocyte migration across the BBB.

Design/Methods The LAMA5 p.Thr3126Ile missense mutation, identified in MS families, was introduced into human umbilical vein endothelial cells (HUVECs) using cytosine base editing. Wild-type and mutant HUVECs were co-cultured with peripheral blood mononuclear cells (PBMCs) in a Transwell 2D co-culture system. PBMC migration was induced with TNFα and IFNγ stimulation. Quantitative PCR was performed to assess the expression of ICAM1, VCAM1, CLDN5, ITGB1, and ITGAL—genes involved in lymphocyte adhesion and transmigration across the BBB.

Results PBMC migration through the mutant HUVEC monolayer was 25% higher compared to wild-type cells. Expression of ICAM1, VCAM1, and CLDN5 was significantly reduced in mutant HUVECs, whereas ITGB1 and ITGAL expression was significantly increased (p < 0.05 for all). These molecular changes indicate compromised BBB integrity and enhanced lymphocyte adhesion and migration in the presence of LAMA5 variants.

Conclusions

The LAMA5 p.Thr3126Ile variant increases lymphocyte infiltration across the BBB, potentially contributing to MS pathogenesis through impaired endothelial barrier function and dysregulated adhesion molecule expression. Ongoing studies using prime editing technology will extend this investigation to additional LAMA5 variants identified in familial MS, providing translational insights into the genetic regulation of BBB integrity in neuroinflammatory diseases.

Authors/Disclosures
Aksel Siva, MD (Istanbul University Cerrahpasa School of Medicine) PRESENTER	Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi-Genzyme. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen - TR. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alexion. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Ali Raif Pharmaceuticals, Turkiye. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanovel Pharmaceuticals, Turkiye. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Abdi Ibrahim Ilac - TR. Dr. Siva has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck Serono . The institution of Dr. Siva has received research support from Turkish MS Society. The institution of Dr. Siva has received research support from The Scientific and Technological Research Council Of Turkey - Health Sciences Research Grants.
Umut Voyvoda (Acibadem University)	Umut Voyvoda has nothing to disclose.
Kerem Cotuk	Mr. Cotuk has nothing to disclose.
Hanbike Efe, Msc student	Ms. Efe has nothing to disclose.
Sevim N. Karisik, Master degree	Ms. Karisik has nothing to disclose.
Meziyet D. Reda, Master Of Science Student	Miss Reda has nothing to disclose.
Betul Cakici (Acibadem University)	No disclosure on file
Elif Celik, Msc	Miss Celik has nothing to disclose.
Ahmet C. Timucin, PhD	Dr. Timucin has nothing to disclose.
Umut I. Onat, PhD	Mrs. Onat has nothing to disclose.
Bade Gulec	Bade Gulec has nothing to disclose.
Melih Tutuncu, MD (ISTANBUL UNIVERSITESI CERRAHPASA TIP FAKULTESI)	Dr. Tutuncu has nothing to disclose.
Ugur Uygunoglu (Cerrahpasa)	Ugur Uygunoglu has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche Turkey . The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen Idec/Gen Pharma of Turkey. The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck-Serono of Turkey. The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanovel of Turkey. The institution of Ugur Uygunoglu has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Genveon of Turkey.
Eda Turanli	The institution of Eda Turanli has received research support from Scientific and Technological Research Council of Turkey (TÜBITAK). The institution of Eda Turanli has received research support from Turkish MS Society. The institution of Eda Turanli has received research support from Acibadem University Scientific Research Projects Commission . The institution of Eda Turanli has received research support from Istanbul University Scientific Research Projects Commission .

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