I read it in Roitt's Essential Immunology.

Plasmablasts are precursor cells of short- and long-lived plasma cells and are generally described as a proliferating fraction of antibody-secreting cells, often found in the bloodstream emigrating to organs such as the bone marrow.

I coudn't find any authentic source repeating the same.

Is it true? Is this book authentic enough to follow?

  • 1
    $\begingroup$ I follow Kuby's for Immunology. I don't know about Riott's but Nature reviews would be the best for immunology. $\endgroup$
    – Polisetty
    Oct 11 '16 at 18:46
  • $\begingroup$ @Polisetty Why do you think it is the best? $\endgroup$
    – Tyto alba
    Oct 11 '16 at 18:50
  • $\begingroup$ They have the latest stuff and amazing diagrams. Like the one below, even the subtle difference that the plasmablast has membrane bound Ig and plasma cells have secretory Ig has been made. $\endgroup$
    – Polisetty
    Oct 11 '16 at 19:06

Antigen activated B-cells enter the germinal centre dark zone to form centroblasts which undergo somatic hypermutation. These then form centrocytes in the light zone. The various possibilities/routes the centrocyte can take are shown in the following figure. If the centrocyte undergoes a class switch recombination, it becomes a plasmablast.

A plasmablast is defined as


The B-cell lineage precursor of non-dividing plasma cells, which has the capacity to divide and that has migratory potential.

Once it matures as a plasma cell, it is out in the blood secreting soluble immunoglobulins or antibodies.

Another important definition to mentioned here would be of antibody secreting cells.

Antibody-secreting cells

A term that denotes both proliferating plasmablasts and non-proliferating plasma cells. The term is used when both cell types might be present

So, yes, they indeed are a precursor of plasma cells.

Also, it is necessary to clarify here that although both plasma cells and plasmablasts are antibody secreting cells, plasma cells lack membrane bound antibodies while plasmablasts retain them.

enter image description here

Finally, this is just the germinal centre response that is shown over here. Plasma cells and plasmablasts can also form in an extrafollicular response in extrafollicular sites in the spleen or in the medullary cords of the liver. That's another story altogether!

For a more detailed explanation, have a look at my other answer.

Image and reference: http://www.nature.com/nri/journal/v8/n1/full/nri2217.html

  • $\begingroup$ In your other answer you mentioned that they produce secreted IgM. This is also mentioned in Kuby. Is it an exception to what you said, they still producing membrane bound antibodies? Could you elaborate? $\endgroup$
    – Tyto alba
    Oct 11 '16 at 19:55
  • $\begingroup$ Thanks for pointing out. There's a small error. I'll update in a while :) $\endgroup$
    – Polisetty
    Oct 11 '16 at 20:01
  • $\begingroup$ Both the answers have been updated @SanjuktaGhosh . Please have a look! Those plasmablasts are different extrafollicular ones $\endgroup$
    – Polisetty
    Oct 11 '16 at 20:36
  • $\begingroup$ I appreciate that. However I regret not having access to the paid website, nature.com. :( $\endgroup$
    – Tyto alba
    Oct 11 '16 at 20:44
  • $\begingroup$ @SanjuktaGhosh Shouldn't you have access via your university? $\endgroup$
    – Ebbinghaus
    Oct 12 '16 at 6:09

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