Ekspresi Transien Protein Rekombinan Spike S1 SARS-CoV-2 Pada Sel CHO (Chinese Hamster Ovary)

Devia Puspita Natalicka; Silvia Tri Widyaningtyas; Fera Ibrahim

doi:10.22435/jbmi.v11i2.6618

Devia Puspita Natalicka Program Magister Ilmu Biomedik, Fakultas Kedokteran, Universitas Indonesia
Silvia Tri Widyaningtyas Pusat Riset Virologi dan Kanker Patobiologi, Fakultas Kedokteran, Universitas Indonesia
Fera Ibrahim Departemen Mikrobiologi, Fakultas Kedokteran, Universitas Indonesia

DOI: https://doi.org/10.22435/jbmi.v11i2.6618

Keywords: SARS-CoV-2, Spike, CHO cells

Abstract

ABSTRAK
SARS-CoV-2 merupakan virus penyebab pandemi infeksi COVID-19 yang dilaporkan pertama kali di Wuhan,
Cina. Berbagai upaya dilakukan untuk menekan kasus infeksi SARS-CoV-2 seperti pengembangan obat, vaksin,
sistem deteksi hingga terapi plasma konvalesen. Protein Spike merupakan target utama antibodi netralisasi.
Antibodi netralisasi pada orang yang telah sembuh dari infeksi COVID-19 merupakan salah satu syarat untuk
menjadi pendonor plasma konvalesen, sehingga diperlukan sistem deteksi antibodi netralisasi seperti tes serologi
berbasis kompetitif ELISA yang mudah, murah, cepat dan tidak membutuhkan BSL3 atau BSL2. Sistem deteksi
ini membutuhkan protein rekombinan spike S1 SARS-CoV-2 sebagai antigen yang dapat diekspresikan pada
berbagai sistem ekspresi. Penelitian ini bertujuan untuk mengekspresikan protein rekombinan spike S1 SARSCoV-2 pada sistem ekspresi mamalia menggunakan sel kultur CHO. Penelitian ini menggunakan plasmid pD609
sebagai vektor ekspresi sel mamalia dan telah disisipkan gen spike S1 SARS-CoV-2. DNA plasmid ditransfeksi
secara transien ke dalam sel CHO selanjutnya post transfeksi dilihat dengan melakukan immunostaining.
Supernatan media sel kultur CHO post transfeksi dianalisis dengan teknik ELISA untuk melihat reaktivitas
terhadap serum konvalesen COVID-19. Hasil immunostaining menunjukkan plasmid pD609 S1 Spike FoldonHis dapat mengekspresikan protein rekombinan spike S1 dan berdasarkan hasil Elisa menunjukkan supernatan
media sel kultur CHO post transfeksi reaktif terhadap serum konvalesen COVID-19.
Kata kunci: SARS-CoV-2, Spike, Sel CHO

ABSTRACT
SARS-CoV-2 is the virus that causes the COVID-19 infection pandemic which was first reported in Wuhan,
China. Various efforts were conducted to suppress cases of SARS-CoV-2 infection, such as the development of
drugs, vaccines, and detection systems for convalescent plasma therapy. Spike protein is the main target of
neutralizing antibodies. Neutralizing antibodies in people who have recovered from COVID-19 infection is one
of the requirements to become convalescent plasma donors, so a neutralizing antibody detection system is
needed such as a competitive ELISA-based serology test that is easy, inexpensive, fast, and does not require
BSL3 or BSL2. This detection system requires recombinant protein SARS-CoV-2 spike S1 as an antigen that can
be expressed in various expression systems. This study aimed to express the SARS-CoV-2 spike S1 recombinant
protein in the mammalian expression system using CHO culture cells. This study used the plasmid pD609 as an
expression vector for mammalian cells and the SARS-CoV-2 S1 Spike gene was inserted. Plasmid DNA was
transiently transfected into CHO cells and post-transfection was seen by immunostaining. Post-transfection
CHO cell culture media supernatants were analysed by ELISA to see the reactivity to COVID-19 convalescent
serum. Immunostaining results showed that the plasmid pD609 S1 Spike Foldon-His could express the
recombinant protein S1 Spike and based on Elisa’s result, the post-transfection CHO cell culture supernatant
was reactive against COVID-19 convalescent serum.
Keywords: SARS-CoV-2, Spike, CHO cells