Simon Hunt | University of Oxford (original) (raw)

Talks by Simon Hunt

Eavesdropping on calcium signals at single-cell level can provide a novel way to classify cell su... more Eavesdropping on calcium signals at single-cell level can provide a novel way to classify cell subpopulations
Technical solutions are needed for internal fluorescence standardisation across the image field
Data reduction and signal recognition algorithms need further development

Papers by Simon Hunt

Journal of Experimental Medicine, 1972

These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixtu... more These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixture of thymus-derived and marrow-derived cells, and define the traffic areas in lymphoid tissues through which the two populations recirculate. Thoracic duct lymphocytes were labeled in vitro with uridine-3H and their histological distribution in the lymphoid tissues of normal recipients was demonstrated by radioautography. Labeled lymphocytes occupied two adjacent areas distinguished by a marked difference in the intensity of labeling; heavily labeled cells were found in thymus-dependent traffic areas of lymphocyte recirculation, while lightly labeled cells localized in the thymus-independent follicular areas around germinal centers. A corresponding heterogeneity of uridine uptake among small lymphocytes from normal donors was demonstrated by sedimentation at 1 g; slowly sedimenting cells incorporated little uridine and localized in follicular areas after transfusion while rapidly sedime...

Journal of Experimental Medicine, 1992

To gain insight into the clonal organization of lymphoid organs, we studied the distribution in s... more To gain insight into the clonal organization of lymphoid organs, we studied the distribution in situ of donor-derived cells in near-physiological chimeras. We introduced RT7b fetal liver cells into nonirradiated congenic RT7a neonatal rats. The chimerism 6-20 wk after injection ranged from 0.3 to 20%. The numbers of cell clones simultaneously contributing to cell generation in a particular histological feature were deduced from the variance in donor cell distribution. In bone marrow and thymus, donor-derived lymphoid cells were found scattered among host cells, indicating a high mobility of cells. In bone marrow, donor cells were evenly distributed over the entire marrow, even at low chimerism. This indicates that leukopoiesis is maintained by the proliferation of many clones. In the thymus, the various lobules showed different quantities of donor-derived lymphoid cells. Mathematical analysis of these differences indicated that 17-18 cell division cycles occur in the cortex. In sple...

Developmental Immunology, 1995

Fetal livers from inbred rat fetuses at 14 days' gestation were dispersed into a single-cell ... more Fetal livers from inbred rat fetuses at 14 days' gestation were dispersed into a single-cell suspension by physical disruption and collagenase digestion. Pluripotent stem cells were characterized and partially purified by a combination of monoclonal antibodies. These included CD71 (anti-transferrin receptor, MRC-Oχ26, used for rosetting), Cdw90 (anti- Thy-1, MRC-Oχ7), and the newly described MRC-Oχ82 (reacting with myeloid cells in peritoneal exudate), employed in FACS sorting. Enrichment was monitored by long-term reconstitution of lethally irradiated congenic rats genetically distinguishable from the donor by an allelomorphic variant of the CD45 cell-surface antigen. At intervals from 3 months to 1 year, lymph-node cells and peritoneal exudate cells were biopsied for analysis by two-color flow cytometry-one color to determine donor origin, the other to identify Th cell (CD4+), Tc cell (CD8+), B cell (sIg+ or CD45RC+ ), neutrophil (Oχ82 + or Oχ43- ), and macrophage (Oχ43+) comp...

Immunology, May 1, 1990

Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germin... more Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes.

Encyclopedia of Life Sciences, 2001

Haematology and blood transfusion, 1980

The EMBO journal, 1984

The frequency of normal rat peripheral B lymphocytes stained for surface immunoglobulin kappa all... more The frequency of normal rat peripheral B lymphocytes stained for surface immunoglobulin kappa allotypes a and b in (a X b) F1 heterozygotes was assessed by two-colour immunofluorescence on a fluorescence-activated cell sorter. The upper limit to the frequency of double- stainers was 8% among all kappa-positive cells, though it was not resolved how far cytophilic antibody accounted for these. Cells expressing each allotype singly were isolated and the extent of rearrangement of the genes encoding the joining-kappa segment on the expressed and non-expressed chromosome were independently assessed. The expressed allele was found to be virtually completely rearranged while the non-expressed allele showed approximately 45-60% rearrangement. The implications of this substantial non-productive rearrangement for models of allelic exclusion are discussed.

Immunology, 1973

... in the literature that B small lymphocytes are stickier than T (Bianco, Patrick and Nussenzwe... more ... in the literature that B small lymphocytes are stickier than T (Bianco, Patrick and Nussenzweig, 1970; Tan and Gordon, 1971; Rosenthal, Davie, Rosenstreich and ... The able technical help given by Miss Rosalind Herbert and Miss Marjorie Sowerby is gratefully acknowledged. ...

Advances in experimental medicine and biology, 1985

Advances in experimental medicine and biology, 1988

Pre-B cells from normal rat bone marrow were isolated by first rosette-depleting granulocytes, T ... more Pre-B cells from normal rat bone marrow were isolated by first rosette-depleting granulocytes, T cells and stem cells with W3/13 mAb and mature B cells with anti-Ig mAb, and then in some samples enriching by FACS-sorting HIS24+ cells. Presumptive precursors of these pre-B cells possessing terminal deoxy-nucleotidyl transferase were prepared by culture of normal marrow. The extent of rearrangement of kappa and heavy chain genes was estimated on both these types of cells and on mature peripheral B cells by measuring the disappearance of the germ-line restriction fragments encoding J segments (other than JH1) relative to a non-rearranging CK fragment. Pre-B cells and B cells showed similar degrees of rearrangement of their kappa genes, leaving roughly half in germ-line form; the TdT+-enriched cells showed approximately similar heavy chain rearrangement as the peripheral B cells. Some non-germ-line restriction fragments hybridising with JH in sufficient amount to register as discrete ba...

Advances in experimental medicine and biology, 1988

Journal of immunology (Baltimore, Md. : 1950), 1987

In rat bone marrow (BM), the B lineage surface antigen HIS24 is expressed by all surface mu chain... more In rat bone marrow (BM), the B lineage surface antigen HIS24 is expressed by all surface mu chain-bearing (s mu+) B cells, by cytoplasmic mu chain-containing (c mu+s mu-) pre-B cells and TdT+ cells, and by lymphoid cells lacking both mu and TdT. Because TdT+ and HIS24+TdT-mu- cells may represent stages in B lymphocytopoiesis before mu chain expression, we investigated their kinetics. The metaphase arrest method was combined with immunofluorescence staining to detect proliferation and to quantitate cell production in the BM pre-B, TdT+, and HIS24+TdT-mu- compartments. Their apparent cell cycle times (tC(a)) were 38, 36, and 19 hr, and the number of cells produced per hour per femur were 58, 9, and 41 X 10(4), respectively. The HIS24+ compartments showed further phenotypic heterogeneity. Six percent of TdT+ cells expressed mu chains and were therefore pre-B cells. Twenty percent of HIS24+TdT-mu- cells expressed Ig other than mu chains, with size distribution and kinetics similar to HI...

Journal of immunology (Baltimore, Md. : 1950), 1986

To investigate early stages of B lymphocytopoiesis in rat bone marrow (BM) before the expression ... more To investigate early stages of B lymphocytopoiesis in rat bone marrow (BM) before the expression of surface IgM (s mu), the populations of cytoplasmic mu-chain-positive (c mu+) pre-B cells and terminal deoxynucleotidyl transferase-positive (TdT+) cells were studied by double immunofluorescence microscopy. B lymphocytes that were s mu+ constituted 5%, c mu+s mu- pre-B cells 23%, and TdT+ cells 4% of nucleated cells in the BM of juvenile rats. TdT+ and pre-B cells ranged between 7 and 17 microns in diameter. TdT+ cells were slightly larger, with a modal diameter of 10.5 microns against 9 microns for pre-B cells. mu-Chains were absent from nearly all TdT+ cells. Their surface antigenic phenotype was studied by using a panel of mouse monoclonal antibodies (MAb) to rat B lymphocyte-associated antigens (Ig, Ia, and others) and T lymphocyte-associated antigens. Both pre-B cells and TdT+ lacked surface Ig and Ia but carried most of the other B lymphocyte-associated antigens analyzed. TdT+ a...

Immunology, 1985

A mouse monoclonal IgG2a antibody, designated MRC OX-26, is shown to be specific for the rat tran... more A mouse monoclonal IgG2a antibody, designated MRC OX-26, is shown to be specific for the rat transferrin receptor, but does not block transferrin binding. The antibody labelled a myeloma, three leukaemia cell lines and normal dividing cells of various types, but also bound to a number of nondividing normal tissues. No labelling of lymphopoietic stem cells could be detected, even though approximately 25% of bone marrow and over 95% of fetal liver cells were clearly labelled.

Immunology, 1989

Athymic PVG-rnu/rnu rats receiving a single intravenous injection of syngeneic euthymic thoracic ... more Athymic PVG-rnu/rnu rats receiving a single intravenous injection of syngeneic euthymic thoracic duct lymphocytes (TDL) develop normal levels of CD4+ T lymphocytes and survive for more than 2 years in a conventional animal house. We investigated the origin of the T cells (and B cells) in reconstituted nude recipients by transferring TDL carrying either the 3T chromosome marker or the RT6b + Igk-1b allotype or the RT7b (leucocyte-common) allotype markers. Karyotype analysis of spleen and lymph node (LN) cells from 1- to 2-year-old PVG-3T/3T-reconstituted nude recipients, stimulated in vitro with phytohaemagglutinin (PHA), unexpectedly revealed that a majority (79-97%) of dividing cells were of nude origin. However, extensive nude cell division was also recorded in PHA-stimulated cultures using mixtures of euthymic (PVG-3T/3T) and unreconstituted nude spleen cells; the assumption that only T cells divide in PHA-stimulated cultures thus appears to be erroneous. In contrast to the karyo...

Immunology, 1990

To determine whether the availability of either B cells or T cells regulates the number and size ... more To determine whether the availability of either B cells or T cells regulates the number and size of germinal centres observed following antigenic challenge, irradiated PVG rats were reconstituted with limiting numbers of thoracic duct B cells (with excess T cells) or with limiting numbers of thoracic duct CD4+ cells (with sufficient B cells). Germinal centre formation was measured histologically in the spleens of reconstituted rats 7 days after immunization with 2 x 10(9) sheep erythrocytes (at the height of the germinal centre reaction). Although reconstitution with B cells and antigen alone, or with thymocytes and antigen alone, produced no germinal centres, saturating numbers of germinal centres on the order observed for normal, non-irradiated rats were observed in irradiated rats reconstituted with only 10(7) B cells and 5 x 10(6) CD4+ cells. Germinal centres in the spleens of minimally reconstituted rats were also comparable in size to those observed in normal rats. Reconstitut...

Immunology, 1990

Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germin... more Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes.

International immunology, 1991

Genetically marked thoracic duct B cell subpopulations rich in either IgD+ or IgD- B cells were t... more Genetically marked thoracic duct B cell subpopulations rich in either IgD+ or IgD- B cells were transferred to non-irradiated, congenic rats in order to compare the capacities of IgD+ versus IgD- B cells to form germinal centers (GCs). This comparison was made quantitatively based on flow cytometric analyses of lymph node cells prepared from chimeric rats 7 days after s.c. immunization. Donor-origin and host-origin B cells were distinguished using anti-Igk antibodies, and GC B cells were distinguished from other B cells in suspension by their lack of labeling with the mAb HIS22. IgK+ HIS22- lymph node cells corresponded well to GC B cells: they contained many large cells, were IgM+ but mostly IgD-, expressed relatively lower levels of IgM than HIS22+ B cells, and increased in number and frequency in response to antigen. Results from flow cytometric analyses, corroborated by immunofluorescence histochemical studies, showed that cell-for-cell, IgD- B cells from GCs much more efficient...

Eavesdropping on calcium signals at single-cell level can provide a novel way to classify cell su... more Eavesdropping on calcium signals at single-cell level can provide a novel way to classify cell subpopulations
Technical solutions are needed for internal fluorescence standardisation across the image field
Data reduction and signal recognition algorithms need further development

Journal of Experimental Medicine, 1972

These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixtu... more These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixture of thymus-derived and marrow-derived cells, and define the traffic areas in lymphoid tissues through which the two populations recirculate. Thoracic duct lymphocytes were labeled in vitro with uridine-3H and their histological distribution in the lymphoid tissues of normal recipients was demonstrated by radioautography. Labeled lymphocytes occupied two adjacent areas distinguished by a marked difference in the intensity of labeling; heavily labeled cells were found in thymus-dependent traffic areas of lymphocyte recirculation, while lightly labeled cells localized in the thymus-independent follicular areas around germinal centers. A corresponding heterogeneity of uridine uptake among small lymphocytes from normal donors was demonstrated by sedimentation at 1 g; slowly sedimenting cells incorporated little uridine and localized in follicular areas after transfusion while rapidly sedime...

Journal of Experimental Medicine, 1992

To gain insight into the clonal organization of lymphoid organs, we studied the distribution in s... more To gain insight into the clonal organization of lymphoid organs, we studied the distribution in situ of donor-derived cells in near-physiological chimeras. We introduced RT7b fetal liver cells into nonirradiated congenic RT7a neonatal rats. The chimerism 6-20 wk after injection ranged from 0.3 to 20%. The numbers of cell clones simultaneously contributing to cell generation in a particular histological feature were deduced from the variance in donor cell distribution. In bone marrow and thymus, donor-derived lymphoid cells were found scattered among host cells, indicating a high mobility of cells. In bone marrow, donor cells were evenly distributed over the entire marrow, even at low chimerism. This indicates that leukopoiesis is maintained by the proliferation of many clones. In the thymus, the various lobules showed different quantities of donor-derived lymphoid cells. Mathematical analysis of these differences indicated that 17-18 cell division cycles occur in the cortex. In sple...

Developmental Immunology, 1995

Fetal livers from inbred rat fetuses at 14 days' gestation were dispersed into a single-cell ... more Fetal livers from inbred rat fetuses at 14 days' gestation were dispersed into a single-cell suspension by physical disruption and collagenase digestion. Pluripotent stem cells were characterized and partially purified by a combination of monoclonal antibodies. These included CD71 (anti-transferrin receptor, MRC-Oχ26, used for rosetting), Cdw90 (anti- Thy-1, MRC-Oχ7), and the newly described MRC-Oχ82 (reacting with myeloid cells in peritoneal exudate), employed in FACS sorting. Enrichment was monitored by long-term reconstitution of lethally irradiated congenic rats genetically distinguishable from the donor by an allelomorphic variant of the CD45 cell-surface antigen. At intervals from 3 months to 1 year, lymph-node cells and peritoneal exudate cells were biopsied for analysis by two-color flow cytometry-one color to determine donor origin, the other to identify Th cell (CD4+), Tc cell (CD8+), B cell (sIg+ or CD45RC+ ), neutrophil (Oχ82 + or Oχ43- ), and macrophage (Oχ43+) comp...

Immunology, May 1, 1990

Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germin... more Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes.

Encyclopedia of Life Sciences, 2001

Haematology and blood transfusion, 1980

The EMBO journal, 1984

The frequency of normal rat peripheral B lymphocytes stained for surface immunoglobulin kappa all... more The frequency of normal rat peripheral B lymphocytes stained for surface immunoglobulin kappa allotypes a and b in (a X b) F1 heterozygotes was assessed by two-colour immunofluorescence on a fluorescence-activated cell sorter. The upper limit to the frequency of double- stainers was 8% among all kappa-positive cells, though it was not resolved how far cytophilic antibody accounted for these. Cells expressing each allotype singly were isolated and the extent of rearrangement of the genes encoding the joining-kappa segment on the expressed and non-expressed chromosome were independently assessed. The expressed allele was found to be virtually completely rearranged while the non-expressed allele showed approximately 45-60% rearrangement. The implications of this substantial non-productive rearrangement for models of allelic exclusion are discussed.

Immunology, 1973

... in the literature that B small lymphocytes are stickier than T (Bianco, Patrick and Nussenzwe... more ... in the literature that B small lymphocytes are stickier than T (Bianco, Patrick and Nussenzweig, 1970; Tan and Gordon, 1971; Rosenthal, Davie, Rosenstreich and ... The able technical help given by Miss Rosalind Herbert and Miss Marjorie Sowerby is gratefully acknowledged. ...

Advances in experimental medicine and biology, 1985

Advances in experimental medicine and biology, 1988

Pre-B cells from normal rat bone marrow were isolated by first rosette-depleting granulocytes, T ... more Pre-B cells from normal rat bone marrow were isolated by first rosette-depleting granulocytes, T cells and stem cells with W3/13 mAb and mature B cells with anti-Ig mAb, and then in some samples enriching by FACS-sorting HIS24+ cells. Presumptive precursors of these pre-B cells possessing terminal deoxy-nucleotidyl transferase were prepared by culture of normal marrow. The extent of rearrangement of kappa and heavy chain genes was estimated on both these types of cells and on mature peripheral B cells by measuring the disappearance of the germ-line restriction fragments encoding J segments (other than JH1) relative to a non-rearranging CK fragment. Pre-B cells and B cells showed similar degrees of rearrangement of their kappa genes, leaving roughly half in germ-line form; the TdT+-enriched cells showed approximately similar heavy chain rearrangement as the peripheral B cells. Some non-germ-line restriction fragments hybridising with JH in sufficient amount to register as discrete ba...

Advances in experimental medicine and biology, 1988

Journal of immunology (Baltimore, Md. : 1950), 1987

In rat bone marrow (BM), the B lineage surface antigen HIS24 is expressed by all surface mu chain... more In rat bone marrow (BM), the B lineage surface antigen HIS24 is expressed by all surface mu chain-bearing (s mu+) B cells, by cytoplasmic mu chain-containing (c mu+s mu-) pre-B cells and TdT+ cells, and by lymphoid cells lacking both mu and TdT. Because TdT+ and HIS24+TdT-mu- cells may represent stages in B lymphocytopoiesis before mu chain expression, we investigated their kinetics. The metaphase arrest method was combined with immunofluorescence staining to detect proliferation and to quantitate cell production in the BM pre-B, TdT+, and HIS24+TdT-mu- compartments. Their apparent cell cycle times (tC(a)) were 38, 36, and 19 hr, and the number of cells produced per hour per femur were 58, 9, and 41 X 10(4), respectively. The HIS24+ compartments showed further phenotypic heterogeneity. Six percent of TdT+ cells expressed mu chains and were therefore pre-B cells. Twenty percent of HIS24+TdT-mu- cells expressed Ig other than mu chains, with size distribution and kinetics similar to HI...

Journal of immunology (Baltimore, Md. : 1950), 1986

To investigate early stages of B lymphocytopoiesis in rat bone marrow (BM) before the expression ... more To investigate early stages of B lymphocytopoiesis in rat bone marrow (BM) before the expression of surface IgM (s mu), the populations of cytoplasmic mu-chain-positive (c mu+) pre-B cells and terminal deoxynucleotidyl transferase-positive (TdT+) cells were studied by double immunofluorescence microscopy. B lymphocytes that were s mu+ constituted 5%, c mu+s mu- pre-B cells 23%, and TdT+ cells 4% of nucleated cells in the BM of juvenile rats. TdT+ and pre-B cells ranged between 7 and 17 microns in diameter. TdT+ cells were slightly larger, with a modal diameter of 10.5 microns against 9 microns for pre-B cells. mu-Chains were absent from nearly all TdT+ cells. Their surface antigenic phenotype was studied by using a panel of mouse monoclonal antibodies (MAb) to rat B lymphocyte-associated antigens (Ig, Ia, and others) and T lymphocyte-associated antigens. Both pre-B cells and TdT+ lacked surface Ig and Ia but carried most of the other B lymphocyte-associated antigens analyzed. TdT+ a...

Immunology, 1985

A mouse monoclonal IgG2a antibody, designated MRC OX-26, is shown to be specific for the rat tran... more A mouse monoclonal IgG2a antibody, designated MRC OX-26, is shown to be specific for the rat transferrin receptor, but does not block transferrin binding. The antibody labelled a myeloma, three leukaemia cell lines and normal dividing cells of various types, but also bound to a number of nondividing normal tissues. No labelling of lymphopoietic stem cells could be detected, even though approximately 25% of bone marrow and over 95% of fetal liver cells were clearly labelled.

Immunology, 1989

Athymic PVG-rnu/rnu rats receiving a single intravenous injection of syngeneic euthymic thoracic ... more Athymic PVG-rnu/rnu rats receiving a single intravenous injection of syngeneic euthymic thoracic duct lymphocytes (TDL) develop normal levels of CD4+ T lymphocytes and survive for more than 2 years in a conventional animal house. We investigated the origin of the T cells (and B cells) in reconstituted nude recipients by transferring TDL carrying either the 3T chromosome marker or the RT6b + Igk-1b allotype or the RT7b (leucocyte-common) allotype markers. Karyotype analysis of spleen and lymph node (LN) cells from 1- to 2-year-old PVG-3T/3T-reconstituted nude recipients, stimulated in vitro with phytohaemagglutinin (PHA), unexpectedly revealed that a majority (79-97%) of dividing cells were of nude origin. However, extensive nude cell division was also recorded in PHA-stimulated cultures using mixtures of euthymic (PVG-3T/3T) and unreconstituted nude spleen cells; the assumption that only T cells divide in PHA-stimulated cultures thus appears to be erroneous. In contrast to the karyo...

Immunology, 1990

To determine whether the availability of either B cells or T cells regulates the number and size ... more To determine whether the availability of either B cells or T cells regulates the number and size of germinal centres observed following antigenic challenge, irradiated PVG rats were reconstituted with limiting numbers of thoracic duct B cells (with excess T cells) or with limiting numbers of thoracic duct CD4+ cells (with sufficient B cells). Germinal centre formation was measured histologically in the spleens of reconstituted rats 7 days after immunization with 2 x 10(9) sheep erythrocytes (at the height of the germinal centre reaction). Although reconstitution with B cells and antigen alone, or with thymocytes and antigen alone, produced no germinal centres, saturating numbers of germinal centres on the order observed for normal, non-irradiated rats were observed in irradiated rats reconstituted with only 10(7) B cells and 5 x 10(6) CD4+ cells. Germinal centres in the spleens of minimally reconstituted rats were also comparable in size to those observed in normal rats. Reconstitut...

Immunology, 1990

Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germin... more Two-colour immunofluorescence histochemistry showed directly that greater than 90% of CD4+ germinal centre T cells in rat spleen or lymph node examined 7 days after immunization bear the antigen recognized by the monoclonal antibody (mAb) ER3. By contrast, only 30-40% of all thoracic duct or lymph node CD4+ cells were ER3+, as determined by two-colour flow cytometry. CD8+ cells were ER3+, but nearly all B cells were ER3-. Thus, germinal centre T cells belong to a subpopulation of CD4+ cells. Because only 25-30% of CD4+ cells that lack higher molecular weight forms of CD45 (i.e. mAb MRC OX32 cells, equivalent to MRC OX22 cells) express ER3, the CD4+ subpopulations defined by ER3 are neither identical nor complementary to the subsets defined by restricted expression of CD45 epitopes.

International immunology, 1991

Genetically marked thoracic duct B cell subpopulations rich in either IgD+ or IgD- B cells were t... more Genetically marked thoracic duct B cell subpopulations rich in either IgD+ or IgD- B cells were transferred to non-irradiated, congenic rats in order to compare the capacities of IgD+ versus IgD- B cells to form germinal centers (GCs). This comparison was made quantitatively based on flow cytometric analyses of lymph node cells prepared from chimeric rats 7 days after s.c. immunization. Donor-origin and host-origin B cells were distinguished using anti-Igk antibodies, and GC B cells were distinguished from other B cells in suspension by their lack of labeling with the mAb HIS22. IgK+ HIS22- lymph node cells corresponded well to GC B cells: they contained many large cells, were IgM+ but mostly IgD-, expressed relatively lower levels of IgM than HIS22+ B cells, and increased in number and frequency in response to antigen. Results from flow cytometric analyses, corroborated by immunofluorescence histochemical studies, showed that cell-for-cell, IgD- B cells from GCs much more efficient...

Biochemical Society transactions, 1976