Limits...
B cell: T cell interactions occur within hepatic granulomas during experimental visceral leishmaniasis.

Moore JW, Beattie L, Dalton JE, Owens BM, Maroof A, Coles MC, Kaye PM - PLoS ONE (2012)

Bottom Line: In infected mice, there was a small increase in mIgM(lo)mIgD(+) mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production.Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment.These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site.

View Article: PubMed Central - PubMed

Affiliation: Centre for Immunology and Infection, Hull York Medical School and Department of Biology, University of York, Heslington, York, United Kingdom.

ABSTRACT
Hepatic resistance to Leishmania donovani infection in mice is associated with the development of granulomas, in which a variety of lymphoid and non-lymphoid populations accumulate. Although previous studies have identified B cells in hepatic granulomas and functional studies in B cell-deficient mice have suggested a role for B cells in the control of experimental visceral leishmaniasis, little is known about the behaviour of B cells in the granuloma microenvironment. Here, we first compared the hepatic B cell population in infected mice, where ≈60% of B cells are located within granulomas, with that of naïve mice. In infected mice, there was a small increase in mIgM(lo)mIgD(+) mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production. Using 2-photon microscopy to quantify the entire intra-granuloma B cell population, in conjunction with the adoptive transfer of polyclonal and HEL-specific BCR-transgenic B cells isolated from L. donovani-infected mice, we demonstrated that B cells accumulate in granulomas over time in an antigen-independent manner. Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment. These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site.

Show MeSH

Related in: MedlinePlus

Endogenous B cell behavior in hepatic granulomas.A. B cell velocity in granulomas of d21-infected Bgreen/Tred mice. Each symbol represents an individual B cell. Bar shows median velocity calculated from 71 B cells in 12 granulomas imaged in two mice. Liver explants tissue from Bgreen/Tred mice was imaged using 2-photon microscopy and B cell-T cell contacts (B) identified by static imaging. The second harmonic signal is also visible (blue). Data represents the mean ± SEM % B cells interacting with T cells (C) and were derived from 25 and 35 granulomas from 2 mice per time point.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3316612&req=5

pone-0034143-g006: Endogenous B cell behavior in hepatic granulomas.A. B cell velocity in granulomas of d21-infected Bgreen/Tred mice. Each symbol represents an individual B cell. Bar shows median velocity calculated from 71 B cells in 12 granulomas imaged in two mice. Liver explants tissue from Bgreen/Tred mice was imaged using 2-photon microscopy and B cell-T cell contacts (B) identified by static imaging. The second harmonic signal is also visible (blue). Data represents the mean ± SEM % B cells interacting with T cells (C) and were derived from 25 and 35 granulomas from 2 mice per time point.

Mentions: As the behaviour of B cells outside of the LN is unknown, we first examined the dynamics of an endogenous B cell population in granulomas of infected Bgreen/Tred mice. B cells moved freely, with average velocity of 4.2±0.3 µm/min (Figure 6A), similar to granuloma T cells [33], [35] and B cells in lymphoid tissue [14], [17], [18], [19]. Under static imaging conditions, T:B conjugates were readily observed, sometimes being associated with collagen fibres that traversed the granuloma (Figure 6B and C).


B cell: T cell interactions occur within hepatic granulomas during experimental visceral leishmaniasis.

Moore JW, Beattie L, Dalton JE, Owens BM, Maroof A, Coles MC, Kaye PM - PLoS ONE (2012)

Endogenous B cell behavior in hepatic granulomas.A. B cell velocity in granulomas of d21-infected Bgreen/Tred mice. Each symbol represents an individual B cell. Bar shows median velocity calculated from 71 B cells in 12 granulomas imaged in two mice. Liver explants tissue from Bgreen/Tred mice was imaged using 2-photon microscopy and B cell-T cell contacts (B) identified by static imaging. The second harmonic signal is also visible (blue). Data represents the mean ± SEM % B cells interacting with T cells (C) and were derived from 25 and 35 granulomas from 2 mice per time point.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3316612&req=5

pone-0034143-g006: Endogenous B cell behavior in hepatic granulomas.A. B cell velocity in granulomas of d21-infected Bgreen/Tred mice. Each symbol represents an individual B cell. Bar shows median velocity calculated from 71 B cells in 12 granulomas imaged in two mice. Liver explants tissue from Bgreen/Tred mice was imaged using 2-photon microscopy and B cell-T cell contacts (B) identified by static imaging. The second harmonic signal is also visible (blue). Data represents the mean ± SEM % B cells interacting with T cells (C) and were derived from 25 and 35 granulomas from 2 mice per time point.
Mentions: As the behaviour of B cells outside of the LN is unknown, we first examined the dynamics of an endogenous B cell population in granulomas of infected Bgreen/Tred mice. B cells moved freely, with average velocity of 4.2±0.3 µm/min (Figure 6A), similar to granuloma T cells [33], [35] and B cells in lymphoid tissue [14], [17], [18], [19]. Under static imaging conditions, T:B conjugates were readily observed, sometimes being associated with collagen fibres that traversed the granuloma (Figure 6B and C).

Bottom Line: In infected mice, there was a small increase in mIgM(lo)mIgD(+) mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production.Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment.These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site.

View Article: PubMed Central - PubMed

Affiliation: Centre for Immunology and Infection, Hull York Medical School and Department of Biology, University of York, Heslington, York, United Kingdom.

ABSTRACT
Hepatic resistance to Leishmania donovani infection in mice is associated with the development of granulomas, in which a variety of lymphoid and non-lymphoid populations accumulate. Although previous studies have identified B cells in hepatic granulomas and functional studies in B cell-deficient mice have suggested a role for B cells in the control of experimental visceral leishmaniasis, little is known about the behaviour of B cells in the granuloma microenvironment. Here, we first compared the hepatic B cell population in infected mice, where ≈60% of B cells are located within granulomas, with that of naïve mice. In infected mice, there was a small increase in mIgM(lo)mIgD(+) mature B2 cells, but no enrichment of B cells with regulatory phenotype or function compared to the naïve hepatic B cell population, as assessed by CD1d and CD5 expression and by IL-10 production. Using 2-photon microscopy to quantify the entire intra-granuloma B cell population, in conjunction with the adoptive transfer of polyclonal and HEL-specific BCR-transgenic B cells isolated from L. donovani-infected mice, we demonstrated that B cells accumulate in granulomas over time in an antigen-independent manner. Intra-vital dynamic imaging was used to demonstrate that within the polyclonal B cell population obtained from L. donovani-infected mice, the frequency of B cells that made multiple long contacts with endogenous T cells was greater than that observed using HEL-specific B cells obtained from the same inflammatory environment. These data indicate, therefore, that a subset of this polyclonal B cell population is capable of making cognate interactions with T cells within this unique environment, and provide the first insights into the dynamics of B cells within an inflammatory site.

Show MeSH
Related in: MedlinePlus