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Characteristics of memory B cells elicited by a highly efficacious HPV vaccine in subjects with no pre-existing immunity.

Scherer EM, Smith RA, Simonich CA, Niyonzima N, Carter JJ, Galloway DA - PLoS Pathog. (2014)

Bottom Line: These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies.Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells.Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation.

View Article: PubMed Central - PubMed

Affiliation: Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.

ABSTRACT
Licensed human papillomavirus (HPV) vaccines provide near complete protection against the types of HPV that most commonly cause anogenital and oropharyngeal cancers (HPV 16 and 18) when administered to individuals naive to these types. These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies. However, almost nothing is known about the immunological memory that forms following HPV vaccination, which is required for long-term immunity. Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells. Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation. These findings suggest that the quadrivalent HPV vaccine provides an excellent model for studying the development of B cell memory; and, in the context of what is known about memory B cells elicited by influenza vaccination/infection, HIV-1 infection, or tetanus toxoid vaccination, indicates that extensive somatic hypermutation is not required to achieve potent vaccine-specific neutralizing antibody responses.

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Non-neutralizing human mAbs 5, 13, 16, and 18 do not bind to HPV 16 psV.Each Ab cloned and expressed in this study was evaluated for binding to HPV 16 psV over a broad dilution range in an ELISA. (A) Representative binding curves from one experiment are plotted with optical density (OD) on the y-axis and Ab dilution on the x-axis. (B) Table summarizing the mean half-maximal binding concentrations, or EC50 values (± SD from two or more experiments), measured for Ab binding to HPV 16 psV. EC50 values were calculated using a non-linear regression model.
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ppat-1004461-g004: Non-neutralizing human mAbs 5, 13, 16, and 18 do not bind to HPV 16 psV.Each Ab cloned and expressed in this study was evaluated for binding to HPV 16 psV over a broad dilution range in an ELISA. (A) Representative binding curves from one experiment are plotted with optical density (OD) on the y-axis and Ab dilution on the x-axis. (B) Table summarizing the mean half-maximal binding concentrations, or EC50 values (± SD from two or more experiments), measured for Ab binding to HPV 16 psV. EC50 values were calculated using a non-linear regression model.

Mentions: Four of the twelve human mAbs (5, 13, 16, and 18) did not neutralize HPV 16 even when tested at dilutions up to 450 nM. Therefore, to learn whether there are differences in the abilities of these Abs to bind vs. neutralize HPV 16, as has been observed for Abs elicited against other viruses (e.g., HIV-1), we evaluated their binding to psV in an ELISA. In this assay, antibodies in serum or plasma are tested for binding to psV immobilized on the surface of polystyrene microtiter plates. Antibody binding is then detected and quantified using a secondary antibody against human IgG. Similar to the neutralization results, we found that Abs 5, 13, 16, and 18 did not bind to HPV 16 L1 in the ELISA, even when tested at concentrations up to 100 nM (Fig. 4A). Therefore, it appears that these Abs are not HPV 16-specific and that the AF488-HPV 16+ Bmem from which they derived represented background or false positives. Such non-specific staining has been observed with other Ag-labeling methods [28].


Characteristics of memory B cells elicited by a highly efficacious HPV vaccine in subjects with no pre-existing immunity.

Scherer EM, Smith RA, Simonich CA, Niyonzima N, Carter JJ, Galloway DA - PLoS Pathog. (2014)

Non-neutralizing human mAbs 5, 13, 16, and 18 do not bind to HPV 16 psV.Each Ab cloned and expressed in this study was evaluated for binding to HPV 16 psV over a broad dilution range in an ELISA. (A) Representative binding curves from one experiment are plotted with optical density (OD) on the y-axis and Ab dilution on the x-axis. (B) Table summarizing the mean half-maximal binding concentrations, or EC50 values (± SD from two or more experiments), measured for Ab binding to HPV 16 psV. EC50 values were calculated using a non-linear regression model.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4199765&req=5

ppat-1004461-g004: Non-neutralizing human mAbs 5, 13, 16, and 18 do not bind to HPV 16 psV.Each Ab cloned and expressed in this study was evaluated for binding to HPV 16 psV over a broad dilution range in an ELISA. (A) Representative binding curves from one experiment are plotted with optical density (OD) on the y-axis and Ab dilution on the x-axis. (B) Table summarizing the mean half-maximal binding concentrations, or EC50 values (± SD from two or more experiments), measured for Ab binding to HPV 16 psV. EC50 values were calculated using a non-linear regression model.
Mentions: Four of the twelve human mAbs (5, 13, 16, and 18) did not neutralize HPV 16 even when tested at dilutions up to 450 nM. Therefore, to learn whether there are differences in the abilities of these Abs to bind vs. neutralize HPV 16, as has been observed for Abs elicited against other viruses (e.g., HIV-1), we evaluated their binding to psV in an ELISA. In this assay, antibodies in serum or plasma are tested for binding to psV immobilized on the surface of polystyrene microtiter plates. Antibody binding is then detected and quantified using a secondary antibody against human IgG. Similar to the neutralization results, we found that Abs 5, 13, 16, and 18 did not bind to HPV 16 L1 in the ELISA, even when tested at concentrations up to 100 nM (Fig. 4A). Therefore, it appears that these Abs are not HPV 16-specific and that the AF488-HPV 16+ Bmem from which they derived represented background or false positives. Such non-specific staining has been observed with other Ag-labeling methods [28].

Bottom Line: These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies.Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells.Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation.

View Article: PubMed Central - PubMed

Affiliation: Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America.

ABSTRACT
Licensed human papillomavirus (HPV) vaccines provide near complete protection against the types of HPV that most commonly cause anogenital and oropharyngeal cancers (HPV 16 and 18) when administered to individuals naive to these types. These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies. However, almost nothing is known about the immunological memory that forms following HPV vaccination, which is required for long-term immunity. Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells. Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation. These findings suggest that the quadrivalent HPV vaccine provides an excellent model for studying the development of B cell memory; and, in the context of what is known about memory B cells elicited by influenza vaccination/infection, HIV-1 infection, or tetanus toxoid vaccination, indicates that extensive somatic hypermutation is not required to achieve potent vaccine-specific neutralizing antibody responses.

Show MeSH
Related in: MedlinePlus