Density Distribution Analysis of Antigen Sensitive Cells in the Rat

Js, Haskill

doi:10.1038/2161229a0

Cited by 19 publications

(2 citation statements)

References 11 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have shown that the responding B cell subset 7 days after boost is enriched in the low density fractions of cells separated o n BSA density gradients. This finding is consistent with those of other workers [ 16,[38][39][40] who have found that the PFC precursors in very recently primed spleens are in a low density, proliferating cell population, whereas long-term memory lymphocytes have high density. We find a poor IgG response in vitro using high density cellsa population potentially contaminated with low density cellswhich tends t o confirm that memory cells d o not respond under these conditions, and that the responding IgG precursors arise by antigen stimulation of memory cells rather than by splenic recruitment.…”

Section: Discussionsupporting

confidence: 94%

IgG response in vitro. I. The requirement for an intermediate responsive cell type

North

Askonas

1976

Eur J Immunol

View full text Add to dashboard Cite

We have studied a secondary IgG anti-dinitrophenyl response in dissociated mouse spleen cell cultures which is comparable in magnitude to the responses detected after adoptive transfer. The data indicate that the responsive precursor cell is not a recirculating memory cell but is an intermediate B cell type which appears in vivo after antigen challenge of primed mice. Both antigen and T helper cells are required for in vitro stimulation of the intermediate cell type into the division and maturation steps leading to IgG antibody secretion. The buoyant density of precursor cells has been analyzed by bovine serum albumin density gradient centrifugation, and is consistent with their recent origin by division from memory cells.

show abstract

Section: Discussionsupporting

confidence: 94%

IgG response in vitro. I. The requirement for an intermediate responsive cell type

North

Askonas

1976

Eur J Immunol

View full text Add to dashboard Cite

show abstract

“…This result agrees with previous cell electrophoresis and adherence column studies in this laboratory (11,12) which characterized most of the unprimed AFC progenitors as atypically fast migrating and exceptionally adherent B cells. The earlier density separation studies of Haskill (37) and Haskill and Marbrook (38) are in general agreement with these conclusions. They are also consistent with recent findings of Strober (13) on the sedimentation characteristics of unprimed AFC progenitors in the rat.…”

Section: Effect Of Age Upon the Sedimentation Velocity Characteristics Of Igm Afc Progenitors Of Germfree Mouse Spleen Slow Sedimenting Dsupporting

confidence: 81%

Antigen-initiated B-lymphocyte differentiation. VIII. Sedimentation velocity and buoyant density characterization of virgin antibody-forming cell progenitors in the adoptive immune response of unprimed CBA mice to 4-hydroxy-3-iodo-5-nitrophenylacetic acid-polymerized bacterial flagellin antigen.

Fidler¹,

Howard²,

Shortman³

1976

The Journal of Experimental Medicine

View full text Add to dashboard Cite

The characteristics of antibody-forming cell (AFC) progenitors lacking previous contact with specific antigen (virgin AFC progenitors) has been studied using sedimentation velocity and buoyant density separation for the investigation of physically distinct B-cell subpopulations. Functional characterization of isolated subsets was made using a quantitative adoptive immune assay for the IgM AFC progenitors responding to the antigen 4-hydroxy-3-iodo-5-nitrophenylacetic acid conjugated polymerized bacterial flagellin. Extensive heterogeneity is present among B lymphocytes, only some subpopulations of which exhibit AFC progenitor function. In the spleen of adult conventional CBA mice, atypically fast sedimenting cells of low buoyant density are active, while typical small B lymphocytes do not appear to be progenitors of IgM AFC. Spleen of adult specific pathogen-free (SPF), germfree, and athymic nude mice give similar results, although a minor population of typical slowly sedimenting dense cells are active in the latter two sources. Adult conventional bone marrow cells are as physically and functionally heterogeneous as splenic B cells, and although a significant proportion of AFC progenitor activity is found among dense, slowly sedimenting cells, most of the activity is among low density, faster sedimenting cells. In contrast to this situation in adult animals, where most of the unprimed AFC progenitors are large, atypical B cells, the spleens of neonatal mice provide a site where virgin AFC progenitors with the physical properties of typical small B lymphocytes are found. While being present in conventional and SPF neonatal spleens, these virgin cells are predominant in 7-day-old germfree mouse spleen. These findings suggest that the newborn virgin B cell is a typical small lymphocyte. However, few cells of this type are found in the adult animal. The unprimed AFC-progenitor population in the adult consists of large, fast sedimenting, low buoyant density, adherent cells, the physical properties of which are characteristic of activated B lymphocytes. It is suggested that these atypical cells are derived from the small newborn virgin B cell by the nonspecific effects of environmental antigenic stimuli.

show abstract

Separation of cells by velocity sedimentation

Miller

Phillips

1969

Journal Cellular Physiology

914

348

View full text Add to dashboard Cite

A system for fractionating populations of Jiving cells by velocity sedimentation in the earth's gravitational field i s described. The cells start in a thin band near the top of a shallow gradient of 3% to 30% fetal calf serum in phosphate buffered saline at 4°C. Cell separation takes pIace primarily on the basis of size and is approximately independent of cell shape. A sharply-defined upper limit, called the streaming limit, exists for the cell concentration in the starting band beyond which useful cell separations cannot be achieved. This limit, which varies with the type of cell being sedimented, can be signBcantly increased by proper choice of gradient shape. For sheep erythrocytes (sedimentation velocity of 1.6 -/hour) it is 1.5 X 1 0 ' cells/ml. Measured and calculated sedimentation velocities for sheep erythrocytes are shown to be in agreement. The technique is applied to a suspension of mouse spleen cells and it is shown, using an electronic cell counter and pulse height analyzer, that cells are fractionated according to size across the gradient such that the sedimentation velocity (in mm/hour) approximately equals r2/4 where r is the cell radius in microns. Since cells of differing function also often differ in size, the system appears to have useful biological applications.

show abstract

Density Distribution Analysis of Antigen Sensitive Cells in the Rat

Cited by 19 publications

References 11 publications

IgG response in vitro. I. The requirement for an intermediate responsive cell type

IgG response in vitro. I. The requirement for an intermediate responsive cell type

Antigen-initiated B-lymphocyte differentiation. VIII. Sedimentation velocity and buoyant density characterization of virgin antibody-forming cell progenitors in the adoptive immune response of unprimed CBA mice to 4-hydroxy-3-iodo-5-nitrophenylacetic acid-polymerized bacterial flagellin antigen.

Separation of cells by velocity sedimentation

Contact Info

Product

Resources

About