18/05/2023

Raji cells

Raji cells constitute the first immortalized human cell line of hematopoietic origin. These lymphoblast-like cells are widely used in immunology research and are a great transfection host.

This article will assist you in learning the basic concepts about the Raji cell line, including:

General characteristics and origin of the Raji cell line
Culturing information about Raji cell line
Raji cell line: Advantages & disadvantages
Applications of Raji cells
Research Publications Featuring Raji Cells
Resources for Raji Cell line: Protocols, Videos, and More

1. General characteristics and origin of the Raji cell line

When you think of working on a cell line, you first look for its general characteristics and origin. This section of the article will help you learn: What are Raji cells? Where did Raji cells come from? What is the morphology of Raji cells? What are the characteristics of the Raji cell line?

Raji, a human B lymphoblastoid cell line, was obtained from the left maxilla of a Nigerian male (11 years old) suffering from Burkitt lymphoma. The cell line was established in 1963 by R.J.V. Pulvertaft.
Raji B cells grow in suspension cultures and form floating clusters of several sizes. These clusters can get bigger as the cell density increases. However, single cells are also found in the Raji cell culture.
The lymphoblast-like cells Raji, possess a relatively small cell diameter ranging from 5-8 μm. Raji cells have an extensive cytoplasm and an irregular indented (slightly curved) nucleus.
Raji cell line exhibits a stale karyotype. They are diploid cells with a stem line number of 46.

Malignant lymphoma tissue investigated under the microscope.

2. Culturing information about Raji cell line

Culturing a cell line is not an easy job if you are not familiar with its key culturing information. Such as for Raji cells, you should know: What is the doubling time of Raji cells? What media is used for Raji B cells? Are Raji cells suspension or adherent? What is the seeding density of Raji cells? What biosafety level are Raji cells?

Key Points for Culturing Raji Cells

Population Doubling Time:	The population doubling time for Raji cells is reported to be 23.2 hours.
Adherent or in Suspension:	Raji cells grow in suspension cultures and form floating clumps.
Seeding Density:	The initial cell density for Raji cells is kept around 1-2 x 10⁵ cells/ml. No passaging solution is required for Raji cells as they grow in suspension culture. Cells are diluted in media and seeded at the required density.
Growth Medium:	Raji cells are cultured in RPMI 1640 media. This media is supplemented with L-glutamine (2.0 mM), L-glucose (2.0 g/L), NaHCO3 (2.0 g/L), and 10% FBS for ideal cell growth.
Growth Conditions:	Raji cell line is cultured in a humidified incubator with a 5% CO2 supply at 37°C temperature.
Storage:	These lymphoblast cells are stored in the vapour phase of liquid nitrogen at below -150°C temperature to protect the viability of cells for the longer term.
Freezing Process and Medium:	CM-1 or CM-ACF freezing media are recommended for Raji cells. A slow freezing process is usually used to freeze cells as it prevents cells from shock and maintains their viability.
Thawing Process:	Frozen Raji cells are kept in the water bath (37°C) for 40 to 60 seconds or until a small ice clump is left. Cells are resuspended in culture media and centrifuged to discard freezing media. Afterwards, cells are diluted in fresh media and poured into the new flask for culturing. The centrifugation step can be skipped; in that case, culture media is replaced after 24 hours.
Biosafety Level:	Raji cell culture requires biosafety level one laboratory settings for handling and maintenance.

Raji cells growing in clusters in suspension.

3. Raji cell line: Advantages & disadvantages

Raji is a well-known Burkitt's lymphoma cell line widely cultured in laboratories. It has a unique combination of advantages and disadvantages associated with it that make it a valuable research tool.

Advantages

The advantages of the Raji cell line are:

High growth rate	Raji cells exhibit a rapid growth rate and are easily propagated in cultures, making them suitable for various cell-based experiments [2].
Immortalized cell line	Raji is a continuous cell line derived from haematological origins. It can proliferate indefinitely in cultures, making it ideal for long-term cell culture experiments.
Susceptible to viral infections	Raji cell cultures are susceptible to viral infections, including Epstein-Barr virus (EBV). Therefore, they are valuable for studying viral infections and developing anti-viral therapies.

Disadvantages

The disadvantages associated with Raji B cells are:

Cancer-derived cell line	Raji cells are derived from a patient with Burkitt's lymphoma, making them a cancerous cell line. Their use may be limited to studying the biology of normal B cells and non-cancerous conditions.
Microbial contamination	Raji B cells are susceptible to microbial infections, including bacteria and fungi. To prevent contamination, it is important to maintain standard aseptic culture conditions.

4. Applications of Raji cells

Raji cells have numerous applications in the immunology field. Some of the significant research applications are listed in this section.

Cancer research: Raji is a tumour-derived cell line; therefore, it is used to study cancer biology, including the cell and molecular mechanisms underlying cancer growth, metastasis, and invasion. A study used the Raji lymphoma cell line to study the mechanisms through which dinaciclib drug induces cell cycle arrest and apoptosis in Raji cells. The detailed research found that dinaciclib exerts these effects by regulating the CDK1-involved pathway [1].
Drug discovery: The lymphoma Raji cells are an excellent research tool to evaluate anti-cancer drugs and therapies. Such as, research conducted in 2021 used Burkitt's lymphoma cells to assess the anti-cancer properties of Zerumbone, a natural compound obtained from the Zingiber zerumbet The study proposed that Zerumbone suppressed Raji cell proliferation by modulating the expression of apoptosis-related genes.
Study of viral infections: Raji cells are susceptible to viral infections thus, are used to study viruses. For example, a study took Epstein Bar virus-infected Raji cells, cocultured them with NK cells, and studied the CD21 ( Epstein Bar virus entry receptor) independent entry into NK cells [3].

5. Research Publications Featuring Raji Cells

Here are some important research publications featuring the Raji cell line.

Effect of Meloxicam on the Proliferation and Apoptosis of the Raji Cell Line: an In Vitro Study

This study was published in 2022 in the International Journal of Dentistry. The study proposed that a nonsteroidal anti-inflammatory drug, Meloxicam, exerts anti-cancer properties in Raji lymphoma cells. It inhibits the proliferation of Raji cells and induces cell death.

Synergistic effect of ibrutinib and CD19 CAR‐T cells on Raji cells in vivo and in vitro

This research article was published in 2020 in the Cancer Science journal. In this study, researchers explored the synergistic effects of CD19 CAR-T cells and ibrutinib drug on Raji lymphoma cells.

Knockdown of long non‑coding RNA PVT1 inhibits the proliferation of Raji cells through cell cycle regulation

This research in Oncology Letters (2019) proposed that lncRNA PVT1 inhibition leads to suppression of Raji cell's proliferation via regulation of cell cycle-associated genes.

Inhibition of JAK2/STAT3 signaling pathway suppresses proliferation of Burkitt's lymphoma Raji cells via cell cycle progression, apoptosis, and oxidative stress by Modulating HSP70

This paper in the Medical Science Monitor (2018) used Raji cells and studied the role of the JAK2/STAT3 signalling pathway in regulating different cell processes, including cell proliferation, cell death, and oxidative stress.

CD21-independent Epstein-Barr virus entry into NK cells

This research was published in Cellular Immunology in 2018. In this study, researchers investigated the CD21 receptor-independent entry of the Epstein-Barr virus to NK cells. For this, they cocultured infected Raji cells and NK cells.

6. Resources for Raji Cell line: Protocols, Videos, and More

There are limited resources on the Raji cell line explaining its culturing and transfection protocols:

Raji cell freezing and thawing: This document contains the protocol for freezing and thawing of Raji cells. Moreover, it also provides a protocol for splitting Raji cells.
Subculture of suspension cells: This video shows a general protocol to subculture suspension cells.

Cell culture protocols

The following link contains the cell culture protocol for Raji cells.

Culturing Raji cells: This website contains important information about Raji cell culture media, freezing media, and protocol for subculturing of these lymphoma cells.

References

Zhao, H., et al., Study of the mechanism by which dinaciclib induces apoptosis and cell cycle arrest of lymphoma Raji cells through a CDK1‐involved pathway. Cancer Medicine, 2019. 8(9): p. 4348-4358.
Albaayit, S.F.A., K. Mariam, and R. Abdullah, Zerumbone induces growth inhibition of Burkitt’s lymphoma cell line via apoptosis. Natural Volatiles and Essential Oils, 2021. 8(3): p. 56-63.
Lee, J.H., et al., CD21-independent Epstein-Barr virus entry into NK cells. Cellular Immunology, 2018. 327: p. 21-25.