A quantitative assessment of primary and secondary immune responses in cattle using a B cell ELISPOT assay.
The aim of the study was to build a comprehensive picture of the appearance in the blood stream of Ag-specific plasma cells and memory B cells in the bovine model. For this purpose, we have developed a method allowing the detection and quantification of both cell types within individual calves immunised with ovalbumin. During the primary response, we detected a burst of ovalbumin-specific plasma cells at days 6 and 7 post-immunisation, which was followed by the production of specific Ab, whereas a gradual increase of memory B cells was only detected from day 15. As expected, a boost immunisation performed 7 weeks later induced a quicker and stronger secondary response. Indeed, a burst of plasma cells was detected in the blood at days 3 and 4, which was followed by a strong increase in Ab titres. Furthermore, a burst of memory B cells, and not a gradual increase, was detected at days 5 and 6 post-boost immunisation. Importantly, we showed a strong correlation between the anti-ovalbumin-specific IgG titres detected 5 months after secondary immunisation and the plasma cell numbers detected in the blood at the peak response after secondary immunisation. The detection and quantification of plasma cells following an mmunisation/vaccination strategy could constitute a very effective means for predicting the magnitude and longevity of an Ab response.
Lefevre
Eric A
EA
Compton Laboratory, Institute for Animal Health, High Street, Compton, Newbury, Berkshire RG20 7NN, United Kingdom. eric.lefevre@bbsrc.ac.uk
Carr
B Veronica
BV
Prentice
Helen
H
Charleston
Bryan
B
D000818:Animals; D000906:Antibodies / Q000097:blood; D000941:Antigens / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology*; D002417:Cattle / Q000097:blood / Q000276:immunology*; D007118:Immunoassay / Q000662:veterinary*; D007156:Immunologic Memory; D007963:Leukocytes, Mononuclear / Q000502:physiology; D010047:Ovalbumin / Q000276:immunology*; D010950:Plasma Cells / Q000276:immunology*
D000906:Antibodies; D000941:Antigens; D010047:Ovalbumin