B Cells

Deliver more. Stress less.

B cells don't get nearly enough love. They present antigen, secrete antibodies, establish long-lived memory, and are quietly powering some of the most exciting therapeutic approaches on the horizon. And yet, when it comes to actually engineering them? Most researchers know the frustration all too well.

B cells are stubbornly resistant to lentiviral transduction, with standard protocols limping along at low single-digit efficiency. Electroporation can force cargo in, but it torches viability, scrambles gene expression, and leaves you with cells that barely resemble what you started with. Not ideal when your whole experiment depends on healthy, functional B cells.

Portal's Gateway system delivers mRNA, proteins, and other cargo directly to the cytosol of primary human B cells through rapid mechanical membrane disruption. No viral vectors, no electrical fields, no apology tour for your cell viability numbers. In mixed PBMC populations, mechanoporation achieves functional mRNA expression in CD19+ B cells alongside T cells, NK cells, and monocytes in a single processing step at high viability. No pre-sorting required. And for researchers who are committed to lentiviral workflows, mechanoporation delivery of a transduction enhancer RNA boosted B cell transduction. It plays nicely with others too.

Below, we break down Portal's B cell delivery data across multiple cargo types and workflows. Your B cells have been through enough. Let's make it easier.

Start delivering now. Experimentally proven delivery workflows for live-cell screening and functional B-cell engineering.

Workflow	Example Cell Type	Cargo	Readout	What this Unlocks
RNA-enabled enhancement of viral gene transfer	Primary human CD19+ B cells	Circular RNA encoding a lentiviral transduction enhancer + GFP lentivirus	Enhancer expression and % GFP+ cells	Improved lentiviral transduction efficiency in primary B cells without viral preconditioning or harsh transfection
Direct mRNA expression in mixed immune samples	CD19+ B cells within mixed PBMCs	GFP mRNA	GFP expression in CD19+ gate	Rapid, isolation-free B-cell programming and functional readouts in heterogeneous immune populations
Antigen delivery for immune activation	Murine splenocytes / human PBMCs	Tumor antigen synthetic long peptides (SLPs) ± CpG adjuvant	CD8+ T cell IFN-γ response	B cell–based antigen presentation with strong downstream T cell activation in co-culture studies
B cell APC engineering	Primary human B cells (CD19+)	mRNA encoding CD86 + membrane-bound IL-2 / IL-12	Surface CD86 expression, downstream T cell IFN-γ, TNF-α, Granzyme B	Convert B cells into potent antigen-presenting cells (BAPCs) for cancer vaccine and immunotherapy applications

Highlighted Data and Applications

Flow cytometry histograms showing expression of a transduction enhancer RNA in primary human CD19+ B cells after mechanoporation. Control cells (gray) show no fluorescence shift, while Boosted cells (purple) show 73% positive expression, confirming efficient intracellular delivery of the B1 Prep Kit transduction enhancer to B cells.

Comparison of GFP expression (% GFP+ cells) in CD19+ B cells across four conditions. Without lentivirus, both Control and Boost show minimal GFP signal. With B1 lentivirus, Control cells reach ~10% GFP+, while Boost-treated cells achieve ~47% GFP+ — a 3.6-fold improvement demonstrating that mechanoporation-delivered transduction enhancer RNA substantially increases lentiviral gene transfer efficiency in primary B cells.

RNA Delivery Unlocks Efficient B-Cell Engineering

Intracellular delivery of RNA enabled strong functional gains in primary human B cells. Following delivery of a circular RNA encoding a lentiviral transduction enhancer, B cells exhibited robust intracellular expression of the enhancer, with 70%+ of cells positive by flow cytometry. This translated directly into a 3.6-fold improvement in downstream gene transfer: exposure to a GFP-encoding lentivirus resulted in 45%+ GFP+ B cells, up from a ~10% baseline without the enhancer — while no-virus conditions showed minimal background signal. These results demonstrate that RNA pre-treatment can substantially improve lentiviral transduction efficiency in primary B cells without compromising cell integrity.

Flow cytometry histograms showing GFP mRNA expression across four major PBMC subsets after mechanoporation. T cells (CD3+), B cells (CD19+), NK cells (CD56+), and Monocytes (CD14+) each show a clear rightward fluorescence shift in Boosted samples (purple) compared to Control (gray), demonstrating efficient cargo delivery to all subsets — including B cells — directly within mixed, unsorted PBMC populations.

Viability of mixed PBMCs after GFP mRNA delivery. Control cells maintain ~97% viability, while Boosted cells retain ~73% viability (n=4, individual data points shown with error bars), confirming that the delivery process preserves strong cell health across the heterogeneous immune population.

Direct mRNA Expression in B Cells Within Mixed Immune Samples

Efficient RNA delivery was also achieved without prior B-cell isolation. In mixed PBMC populations, delivery of GFP mRNA resulted in a clear increase in GFP expression specifically within the CD19+ B-cell compartment, with minimal signal in untreated controls. This confirms that B cells can be selectively and efficiently programmed directly within heterogeneous immune samples, supporting streamlined workflows and physiologically relevant immune assays.

One Platform. Many Cargo Types.

A single delivery platform that supports diverse cargo classes in primary B cells, individually or in combination, without re-optimizing workflows or compromising cell viability or immune function.

What Teams Deliver

mRNA for transient expression of reporters, receptors, cytokines, or antibody chains
circRNA for durable protein expression with reduced innate immune activation
siRNA / RNAi for transient knockdown of B-cell signaling or differentiation regulators
RNA-based transduction enhancers to improve viral gene delivery efficiency
Proteins including transcription factors or signaling modulators
Polymers & tracking reagents for intracellular labeling and fate tracking
Multi-cargo delivery for combinatorial B-cell programming
Functional immune engineering workflows without viral preconditioning
Conditioning-resilient treatments that preserve B-cell viability and function
Built-for-scale workflows compatible with plate-based and automated systems