摘要:

AbstractA new system to obtain large numbers of functionally competent hapten‐specific effector helper T cells has been developed. Mice were primed in the tail with syngeneic spleen cells derivatized with one of three different haptens: 2,4,6‐trinitrophenyl, fluorescein isothiocyanate and 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl. Draining lymph node cells were subsequently restimulated in culture with the homologous antigen for periods up to 6 weeks. More than 99% and 90% of the cells recovered from these preparative cultures, expressed Thy‐1 and Lyt‐1 antigens, respectively. These cells proliferated specifically in response to the homologous stimulation by haptenated syngeneic spleen cells, and they were found to display very high levels of hapten‐specific helper activity, as assayed in a new, universal method for testing T ‐ B cell cooperation, where every B cell can potentially respond to specific T cell help. Coculture of hapten‐derivatized, functionally competent B cells with hapten‐specific T cells obtained from the preparative cultures, resulted in the appearance, and exponential increase with time, of very large numbers of IgM and IgG plaque‐forming cells. This helper activity could be shown to be: specific for the immunizing hapten and to increase with the time ofin vitrohelper cell enrichment, which also resulted in higher average avidities expressed by the helper cell populations. This methodology appears valuable for structural studies on hapten‐specific helper cells, as well as for the functional analysis of effector h

ISSN:0014-2980    

DOI:10.1002/eji.1830100602

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractHelper T cells can be raised in CBA mice with specificity for syngeneic spleen cells derivatized with each of the three haptens, trinitrophenyl (TNP), fluorescein isothiocyanate (FITC) and 3‐(p‐sulfophenyldiazo)‐4‐hydroxyphenyl (SP). These helper cells are exquisitely specific for the homologous antigens, since they express helper activity on target B cells derivatized with hapten concentrations 100‐fold lower than those used for priming, while being totally unable to recognize the heterologous hapten modifications. Expression of helper activity,i.e. induction of target B cells, requires the simultaneous recognition of antigen and I‐A‐ or I‐E/C‐encoded determinants directly on therespondingB cell surfaces.Helper T cells raised in DBA/2 mice with specificity for the same hapten modifications, while functionally recognizing as efficiently as CBA helper cells densely coupled target cells, fail to interact with syngeneic cells derivatized with low concentrations of any of the three haptens. Furthermore, DBA/2 helper cells show a unique “fine specificity” pattern in that anti‐FITC DBA/2 helpers cross‐rea

ISSN:0014-2980    

DOI:10.1002/eji.1830100603

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractRabbit antisera to membrane preparations of human thymocytes (anti‐HTLA), T lymphocytes of the MOLT 4 cell line or B lymphocytes of the LIK cell line, have been serologically characterized and used for the identification of surface membrane antigens specifically expressed by human lymphocyte subpopulations. By immunoprecipitation of surface125I‐ or NaB (3H)4‐labeled protein followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis of the precipitates, the anti‐HTLA antiserum was shown to detect on thymocytes three glycoproteins of apparent molecular weights 160000, 110000 and 45000. The first two only appeared to be sialylated. A similar pattern of antigens could be detected on cultured T lymphocytes, except for the 45 kDalton glycoprotein which could not be detected on the surface of these cells. None of these proteins were detected on125I‐labeled Raji cells. The serological specificity of the anti‐MOLT 4 antiserum for T lymphocytes was more restricted since it only precipitated the 160 kDalton antigen. In addition, the 45 kDalton protein was shown to be sensitive to trypsin treatment as was the sheep red blood cell (SRBC) receptor. The results shown suggest a possible activity as SRBC receptor for this particular protein. In contrast, the anti‐LIK antiserum which behaves as an anti‐HLA‐DR reagent in cytotoxicity testing, only precipitates from cultured B lymphocyte lysates the typical Ia‐like 28 and 33 k

ISSN:0014-2980    

DOI:10.1002/eji.1830100604

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe identity of cells producing interferon among human peripheral blood lymphocytes in contact with tumor cells was investigated. The producer cells were target cell‐adherent lymphocytic cells morphologically similar to natural killer (NK) cells. As interferon is known to augment the cytotoxic activity of initially inactive “pre‐NK” cells, the results suggest an internal positive feedback mechanism in the activation of N

ISSN:0014-2980    

DOI:10.1002/eji.1830100605

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractA macrophage‐activating factor (MAF), produced by concanavalin (Con A)‐stimulated spleen lymphocytes, was tested by its capacity to induce mouse peritoneal exudate macrophages to destroy the intracellular parasiteLeishmania enriettii. MAF could be removed from active media by adsorption on macrophages at 37°C and 4°C; the adsorption was not specific, as cells from various origins could similarly be used to deplete supernatants of their activity. Treatment of macrophages with trypsin resulted in loss of response to MAF, presumably due to inactivation of a membrane receptor for the lymphokine. In addition, trypsin treatment of macrophages, following a 6‐h pulse, but not a 9‐h‐pulse, of MAF‐rich medium, inhibited activation suggesting that triggering of the biochemical processes of activation required interaction between macrophages and the lymphokine of sufficient duration, and that once these processes were initiated, parasite destruction could proceed to completion in the absence of further exogenous lymphokine. MAF activity was enhanced by treatment of macrophages with al‐antitrypsin suggesting a role for membrane‐associated serine esterases in modulating the cell response to the lymphokine. High concentrations of Con A also impaired MAF‐induced activation, presumably through binding of the lymph

ISSN:0014-2980    

DOI:10.1002/eji.1830100606

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe mode of interaction of twelve lectins with human T lymphocytes was investigated. In order to establish possible differences between mitogenic and nonmitogenic lectins, they were studied for their capacity to induce or inhibit DNA synthesis. Their interaction with intact T cells was studied by immunofluorescence and51Cr release. Further, lectins conjugated to Sepharose were investigated with regard to their capacity to bind surface glycopeptides from T cell lysates. Operationally, the lectins could be divided into three groups: (a) mitogenic lectins; (b) lectins inhibitory for lymphocyte mitogenesis as induced by leucoagglutinin (La) fromPhaseolus vulgaris; and (c) nonmitogenic lectins which were noninhibitory in this La system. Six lectins were nonmitogenic. For two or possibly three of these, lack of mitogenicity was due to complete or partial failure to bind to the lymphocytes. This explanation could not account for lack of mitogenicity of the other three nonmitogenic lectins. Only two of the lectins utilized inhibited La‐induced mitogenesis. However, when the lectins were compared with regard to their capacity to bind surface glycopeptides from T cell lysates, important differences between mitogenic and nonmitogenic lectins were seen. As revealed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate and autoradiography, the mitogenic lectins bound a larger number of surface glycopeptides (15–20) than the nonmitogenic lectins (3–10). More importantly, five distinct glycopeptides (gp 135 K, 125 K, 105 K, 95 K and 43 K) were bound by all mitogenic lectins but not by the nonmitogenic lectins. It remains to be established whether these glycopeptides are present on the T cells which are susceptible to the mitogenic action of the lectins and whether it is the interaction of the lectins with one or several of them which triggers mitogen

ISSN:0014-2980    

DOI:10.1002/eji.1830100607

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThe appearance of complement receptors (CR) on memory B cells was used as a measure of memory cell maturation. At various times after priming, lymphocytes were separated by rosette formation (EAC‐RFC) and Ficoll‐Hypaque separation followed by transfer to carrier‐primed, irradiated recipients. The relative contribution of the CR+and CR−memory cells to the total memory cell response was then calculated using the amount of antibody produced, corrected for the yield and number of B cells in each fraction. Using this technique, the following results were obtained: (a) in agreement with other investigators, the mature memory cell population is composed of both CR+and CR−cells; (b) early after immunization (2 and 4 weeks), the predominate memory cell population is CR−, while later (6 to 8 months) the CR+cells can contribute an average of 50% of the response; (c) at all times tested, the CR−B cell population was greatly enriched for memory cell activity, and (d) the shift from CR+to CR−by some of the memory cells seemed to accompany a chan

ISSN:0014-2980    

DOI:10.1002/eji.1830100608

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractFeedback regulatory signals to an intermediary suppressor cell may provide the mechanism of the suppression of antibody responses which has been described in cocultures of primed (immune) and unprimed (normal) spleen cells. The active cell(s) in the unprimed spleen population is nonadherent to nylon wool, Sephadex G‐10 and glass beads. Lymph node cells and cortisone‐resistant thymocytes from normal animals act similarly to normal spleen cells in this coculture system. Spleen cells from homozygous nude mice, unlike their heterozygous thymus‐bearing littermates, do not produce a high degree of suppression in coculture with immune spleen cells. These data strongly suggest that the normal cell which interacts with primed cells in the cocultures to produce suppression is of thymic origin. However, spleen cells from neonatally thymectomized mice are suppressive in the presence of spleen cells immune to sheep red blood cells. The unprimed cell(s) active in the suppression are sensitive (in the presence of complement) to antisera directed against the surface markers, Thy‐1, Qa‐1, Lyt‐1, Lyt‐2, and Ia. Most of the antiserum treatments abrogated the suppressive capacity of the normal spleen cells only partially. Only treatment with anti‐Qa‐1 and complement routinely eliminated the ability of these cells to suppress in the cocultures suggesting either low concentration of or inaccessible surface alloantigen on the active cells. Alternatively, more than one Qa‐1‐positive cell set from the unprimed population may be involved. It is postulated that there is at least one subset of Qa‐1‐positive T lymphocytes present in unprimed spleen and lymph node cell populations capable of participating in the suppression of specific secondary antibody responses when cocultured with spleen cells from sp

ISSN:0014-2980    

DOI:10.1002/eji.1830100609

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractPrevious studies have shown that when a subline of plasmacytoma LPC‐1 is grown in ascites form, the tumor cells harvested after 10–12 days (“late” cells) are resistant to lysis by cytotoxic T lymphocytes (CTL), apparently because the cell surface H‐2‐encoded molecules are blocked by a trypsin‐sensitive glycoprotein of approximately 160 kdaltons. The glycoprotein (gp 160) is produced, and accumulates on the cell surface, as the growing cells enter the stationary phase. In contrast, LPC‐1 cells harvested from the peritoneal cavity early in the transplantation cycle (ca. 4 days), while in exponential growth (“early” cells), have far less gp 160 and are susceptible to lysis by CTL. It is shown that, compared with early cells, the late LPC‐1 cells are far less effective in adsorbing antibodies to products of the H‐2 Kdand H‐2 Ddalleles, but only slightly less effective in adsorbing antibodies to la antigen, and fully effective in adsorbing antibodies to several antigens not related to H‐2 (e.g. PC.1, gp70, gp100, B220). The differences suggest that gp160 might preferentially block H‐2‐encoded molecules (especially K and D)Gp160 was also detected on another myeloma, MOPC 315 OPEC, a subline of MOPC 315, where it also appeared to block H‐2 molecules but not PC.1. Additional evidence for an interaction between gp160 and H‐2 molecules was obtained when sonicated membrane fragments were used to elicit secondary CTL responses to H‐2 in culture. The response could be elicited by fragments from early but not from late LPC‐1 cells, unless the late cells were treated with subtilis

ISSN:0014-2980    

DOI:10.1002/eji.1830100610

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY

摘要:

AbstractThree different approaches have been used to study nonsecreting variants of myeloma and hybrid myeloma lines. Hemolytic plaque assays were used to screen nonsecreting and light (L) chain‐secreting anti‐sheep red blood cell hybrid myeloma variants for reversion to specific antibody or immunoglobulin (Ig) production. No revert ants were detected from among 1.5 × 107−4.2 × 107cells of each line studied. In the absence of a heavy (H) chain, the P3 (MOPC 21) x chain is not secreted but degraded intracellularly. The nature of this secretion defect was investigated in a hybrid myeloma line that produces the P3 x chain and another L chain which is secreted without an H chain, by biochemical studies of the relative distribution of mRNA activity for the two L chains between membrane‐bound and free polysomal fractions. The mutant P3 H chain (H*) produced by the line P3‐NSII/1 is also degraded intracellularly rather than secreted. This defect was complemented by cell fusion of P 3‐NSII/1 to P1, a different Ig‐secreting myeloma line. Mutant H* chains were only secreted as part of hybrid Ig molecules with P1 L chains indicating that the defect in their secretion in the P 3‐ NSII/l line was due to lack of a complementary Ig chain. Additionally, the preferential recovery of P1 H chain loss variants from these hybrids that are producing two H chains and only one L chain, supports the idea that free intracellular H chains have an effect on cell viability and influence the type of variants recovered from hyb

ISSN:0014-2980    

DOI:10.1002/eji.1830100611

出版商:WILEY‐VCH Verlag GmbH    

年代:1980

数据来源: WILEY