The time course, localization and quantitation of T- and B-cell mitogen-driven apoptosis in vivo

Stimulation of sensitized lymphocytes by specific antigen in vitro leads to the production of migration inhibition factor (MIF). In the case of the pure soluble protein, or hapten-protein antigens used in the present studies, this MIF production was a property of the T lymphocytes in the cell suspensions. When PPD was used, B cells, as well as T cells, produced MIF. Similarly, PPD could stimulate B cells to mediate the macrophage disappearance reaction, a reaction which is known to be a T cell-dependent in vivo manifestation of cell-mediated immunity. Suspensions of lymphocytes from nonimmune donors could also be stimulated by PPD; in this case, B cells, but not T cells, produced MIF. The factors produced by the two lymphocyte subpopulations appeared to be similar, if not identical, on the basis of physico-chemical criteria. It is suggested that PPD stimulates B cells for MIF production because of its role as a B cell mitogen. The ability of endotoxin lipopolysaccharide, another B cell mitogen, to also induce MIF production by B cells supports this contention. Thus, although activation of lymphocytes for MIF production by specific antigen is a property of T cells, B cells as well as T cells may be so activated by agents which act nonspecifically. This may prove to have implications for in vivo events involved in immunization. In addition, these observations lend further support to the concept that lymphokine production represents a general biologic phenomenon in addition to playing a role in the effector mechanisms for reactions of cell-mediated immunity.

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Immunologic properties of bacterial lipopolysaccharide (LPS). III. Genetic linkage between the in vitro mitogenic and in vivo adjuvant properties of LPS.

Journal of Experimental Medicine ◽

10.1084/jem.143.1.143 ◽

1976 ◽

Vol 143 (1) ◽

pp. 143-150 ◽

Cited By ~ 37

Author(s):

B J Skidmore ◽

J M Chiller ◽

W O Weigle ◽

R Riblet ◽

J Watson

Keyword(s):

B Cells ◽

B Cell ◽

Tolerance Induction ◽

Backcross Progeny ◽

Bacterial Lipopolysaccharide ◽

Adjuvant Activity ◽

F1 Hybrid ◽

Cell Mitogen

The mechanism was investigated underlying the activity of bacterial lipopolysaccharide (LPS) as an adjuvant of antibody formation as assessed by its capacity to modulate the induction of tolerance in mice to the antigen human Ig G (HGG) into a state of immunity to HGG. The adjuvant activity of LPS was found to be closely correlated with its ability to function as a B-cell mitogen. This correlation was revealed by an analysis of the genetic control of the mitogenic and adjuvant properties of LPS utilizing the refractory state inherent in the C3H/HeJ mouse strain to these activities of LPS. Thus, mice that were the progeny of a backcross between the nonresponder C3H/JeJ parent and the responder (C3H/HeJ X CWB) F1 hybrid were individually typed for responsiveness to LPS, as an adjuvant and as a B-cell mitogen. It was found that LPS interfered with tolerance induction to HGG in vivo only in those backcross progeny whose spleen cells were also capable of responding mitogenically to LPS in vitro, demonstrating that the adjuvant and B-cell mitogenic properties of LPS are genetically linked. In contrast, these properties were observed to segregate independently from either H-2 or heavy chain allotype loci, and were not sex linked. These results are compatible with the concepts that, in this system, (a) the cellular site of action of LPS as an adjuvant is confined to B cells, and (b) the subcellular mode of action of LPS as an adjuvant may involve the delivery of a "signal" to B cells which is a stimulus for mitogenesis.

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Neurite outgrowth induced by an endothelial cell mitogen isolated from retina.

The Journal of Cell Biology ◽

10.1083/jcb.103.4.1363 ◽

1986 ◽

Vol 103 (4) ◽

pp. 1363-1367 ◽

Cited By ~ 95

Author(s):

J A Wagner ◽

P A D'Amore

Keyword(s):

Growth Factor ◽

Neurite Outgrowth ◽

Time Course ◽

Physiological Role ◽

Cell Types ◽

Regulatory Elements ◽

Neural Connections ◽

Neurite Formation ◽

Cell Mitogen

Retina-derived growth factor (RDGF) is a polypeptide growth factor purified from salt extracts of bovine retinas on the basis of its mitogenic activity for capillary endothelial cells (EC) and BALB/c 3T3 cells. RDGF is angiogenic in vivo. We show here that RDGF induces neurite extension by PC12 cells and that this neurite outgrowth is dramatically potentiated by heparin. Neurite formation elicited by RDGF in the presence of heparin cannot be distinguished from that elicited by nerve growth factor (NGF) either by the time course of neurite formation or by the morphology of the neurites at the level of the light microscope. Neurite outgrowth induced by either purified RDGF or by a crude retinal extract is not blocked by antibodies to NGF. Furthermore, neurite outgrowth induced by NGF is not potentiated by heparin and NGF is not mitogenic for capillary EC. Thus, RDGF has profound regulatory effects on cell types of very different embryonic origins. These results indicate that the physiological role for this growth factor may be far more complex than previously suspected and suggest that the formation of neural connections and the process of vascularization may unexpectedly share common regulatory elements.

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Immunomodulating activity of meningococcal antigens

Canadian Journal of Microbiology ◽

10.1139/m83-247 ◽

1983 ◽

Vol 29 (12) ◽

pp. 1611-1618 ◽

Cited By ~ 5

Author(s):

Brian G. Sparkes

Keyword(s):

T Cell ◽

B Cell ◽

Outer Membrane Proteins ◽

Cell Responses ◽

T Cell Suppression ◽

Cell Suppression ◽

Cell Mitogen

A preparation of meningococcal antigens (MA) extracted in CaCl2, and containing mostly outer membrane proteins, was strongly mitogenic for murine B lymphocytes. Given to mice in vitro, MA markedly impaired subsequent in vivo T-cell responses of splenocytes. Suppression of normal T splenocytes in vitro occurred with both adherent (Ad) and nonadherent (NA) splenocytes from MA-sensitized mice. B cells were much less affected by the suppression induced by MA, and only Ad cells could convey in vitro the low level impairment of B-cell proliferation. Strong T-cell suppression associated with a B-cell mitogen is also produced by bacillus Calmette-Guérin (BCG) and Corynebacterium parvum. The possible role of these phenomena in meningococcal disease is discussed.

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In vivo CD40-gp39 interactions are essential for thymus-dependent humoral immunity. I. In vivo expression of CD40 ligand, cytokines, and antibody production delineates sites of cognate T-B cell interactions.

Journal of Experimental Medicine ◽

10.1084/jem.178.5.1555 ◽

1993 ◽

Vol 178 (5) ◽

pp. 1555-1565 ◽

Cited By ~ 171

Author(s):

A J Van den Eertwegh ◽

R J Noelle ◽

M Roy ◽

D M Shepherd ◽

A Aruffo ◽

...

Keyword(s):

T Cells ◽

B Cell ◽

Time Course ◽

Cytokine Production ◽

Cell Interactions ◽

Antibody Responses ◽

B Cell Differentiation ◽

Ifn Gamma ◽

Th Cells

T-B cell interactions have a central role in the development of antibody responses. Upon activation, T helper (Th) cells express the ligand for CD40, gp39, which is essential for Th cell-dependent B cell activation. The cytokines produced by activated Th cells have a regulatory role in B cell differentiation. In this study, we investigated, using immunohistochemical techniques, the in vivo time course and localization of gp39 expression and cytokine production in relation to the specific antibody production. Both the immunization with keyhole limpet hemocyanin (KLH), a thymus-dependent (TD) antigen, and trinitrophenyl (TNP)-Ficoll, a thymus-independent type 2 (TI-2) antigen, induced Th cells to express gp39. The expression of gp39 was restricted to Th cells in the outer periarteriolar lymphocyte sheaths (outer-PALS) and around the terminal arterioles (TA). Incidentally, gp39+ Th cells were found in the corona of follicles, whereas gp39+ cells were never found in the germinal centers or marginal zones of the spleen. Maximum frequencies of gp39+ cells were observed 3 and 4 d after primary and secondary immunization with KLH. After injection of TNP-Ficoll, a marked increase in gp39+ cells was observed, confirming previous observations that activated T cells are involved in TI-2 antibody responses. Analysis of the in vivo cytokine production revealed that interleukin 2 (IL-2)-, IL-4- and interferon gamma (IFN-gamma)-producing cells (IFN-gamma-PC) developed according to similar kinetics as observed for gp39+ cells. IL-2-PC and IL-4-PC were present in higher frequencies as were IFN-gamma-PC in the immune response against TNP-KLH. Double staining experiments revealed gp39+ Th cells producing IL-2, IL-4, or IFN-gamma, suggesting that these cells were involved in both the initial activation as well as the differentiation process of B cells into antibody-forming cells. Dual immunohistochemical analysis revealed gp39+ T cells and cytokine-PC in close proximity to antigen-specific, antibody-forming B cells. In conclusion, this study shows that in vivo gp39 is expressed on activated Th cells after immunization with TD and TI-2 antigens. Furthermore, the time course and compartmentalization of gp39+ expression, cytokine production and antibody formation after immunization suggest that cognate T-B cell interactions and T cell-regulated B cell differentiation occur in the outer-PALS and around the TA of the spleen.

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Release from maternally-induced allotypic suppression in rabbit by Nocardia water-soluble mitogen.

Journal of Experimental Medicine ◽

10.1084/jem.146.3.881 ◽

1977 ◽

Vol 146 (3) ◽

pp. 881-886 ◽

Cited By ~ 9

Author(s):

C Bona ◽

P A Cazenave

Keyword(s):

B Cell ◽

Plasma Cells ◽

Water Soluble ◽

In Vitro Synthesis ◽

Polyclonal Activation ◽

Cell Mitogen

The in vitro synthesis of allotypes of b4/b5 offspring obtained from b4/b4 mothers immunized against paternal allotype b5/b5 was studied in comparison to similar offspring that had escaped from suppression and normal heterozygous b4/b5 rabbits. Nocardia water-soluble mitogen-a rabbit B-cell mitogen which is known to induce the differentiation of small lymphocytes into plasma cells and polyclonal activation of Ig, was able to break in vitro the allotypic suppression induced in vivo.

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Genetical control of B-cell responses. III. Requirement for functional mitogenicity of the antigen in thymus-independent specific responses.

Journal of Experimental Medicine ◽

10.1084/jem.141.4.753 ◽

1975 ◽

Vol 141 (4) ◽

pp. 753-760 ◽

Cited By ~ 17

Author(s):

A Coutinho ◽

E Gronowicz

Keyword(s):

B Cell ◽

High Responder ◽

Spleen Cells ◽

Purified Protein Derivative ◽

Absolute Requirement ◽

Dependent Form ◽

Low Responder ◽

Cell Mitogen

Spleen cells from C3H/HeJ mice fail to respond with polyclonal antibody synthesis to mitogenic concentrations of lipopolysaccharide (LPS) which are optimal for activating spleen cells from a high-responder strain (B10.5M). This unresponsiveness is selective for LPS, since C3H/HeJ cells respond as normals to another B-cell mitogen, purified protein derivative of tuberculin. Spleen cells from low-responder mice also fail to mount a specific anti-NNP plaque-forming cell (PFC) response, when challenged in vitro by NNP-LPS. However, C3H/HeJ cells develop normal responses to another thymus-independent hapten conjugate, DNP-AECM-Ficoll. C3H/HeJ mice fail to mount a specific anti-LPS antibody response, when challenged in vivo with doses of soluble LPS which are fully immunogenic for the high-responder strain. However, C3H/HeJ mice develop normal direct and indirect PFC responses to LPS, when challenged with a thymus-dependent form of the immunogen. These results are interpreted as indicating as absolute requirement for functional mitogenicity of the antigen, in the induction of specific thymus-independent antibody responses.

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Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646468 ◽

1991 ◽

Vol 66 (05) ◽

pp. 609-613 ◽

Cited By ~ 14

Author(s):

I R MacGregor ◽

J M Ferguson ◽

L F McLaughlin ◽

T Burnouf ◽

C V Prowse

Keyword(s):

High Purity ◽

Time Course ◽

Prothrombin Complex Concentrate ◽

Degradation Products ◽

Canine Model ◽

Factor Ix ◽

In Vitro Tests ◽

Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

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