Physiology of IgD. IV. Enhancement of antibody production in mice bearing IgD-secreting plasmacytomas

Immune responses to trinitrophenylated hemocyanin (TNP-KLH), Ficoll (TNP-Ficoll), and Brucella abortus (TNP-BA) were examined in BALB/c mice bearing subcutaneous transplants of TEPC-1017 and TEPC-1033, the two known IgD-secreting BALB/c plasmacytomas. Both primary and secondary 19S and 7S splenic plaque-forming cell (PFC) responses in spleen to intravenously injected TNP-KLH were enhanced three to fivefold. Primary responses to TNP-Ficoll were 1.5-2 times higher than in control mice (particularly the 7S PFC response). Primary responses to TNP-BA were enhanced by TEPC-1017 but suppressed by TEPC-1033, while secondary responses to TNP-BA were enhanced three to sevenfold by both tumors. Intraperitoneal injections of ascites fluid from mice bearing TEPC-1017 or TEPC-1033, or of IgD isolated from such ascites fluid, caused a similar enhancement of the primary response to TNP-KLH, as did the tumor itself, particularly when injected approximately 1 wk before antigen injection. IgD-containing ascites fluid had no effect on the response of athymic (nu/nu) BALB/c mice to TNP-KLH. These findings suggest the existence of an IgD-responsive immunoregulatory T cell.

Physiology of IgD. III. Effect of treatment with anti-IgD from birth on the magnitude and isotype distribution of the immune response in the spleen

Continued treatment with monoclonal anti-IgD (Ig-5a) from birth in BALB/c mice causes a markedly increased responsiveness to i.v. injected dinitrophenylated ovalbumin (DNP-OVA) with Bordetella pertussis at the age of 8 weeks. The 19S plaque-forming cell (PFC)/spleen response is particularly enhanced, 6-8-fold, but all the other isotypes also show increases of 2-6-fold, including IgA and IgE. Both primary and secondary PFC responses and serum antibody titers are enhanced. After transfer of spleen cells from anti-Ig-treated mice to irradiated recipients the IgM/IgG ratio becomes similar to that of controls. In contrast, the response of anti-IgD-treated mice to i.p. immunization with either 0.2 or 100 micrograms DNP-OVA plus alum is reduced by approximately 80% for each Ig isotype except IgM and remains low upon transfer of spleen cells to recipients. It is concluded that the paucity of B cells in peripheral lymph nodes of the anti-IgD-treated mice causes the low responsiveness to i.p. immunization, but that the IgD- B cells in the spleen are quite able to respond and are, in fact, more responsive than IgD+ B cells. This increased responsiveness, together with the higher IgM/IgG ratios for all Ig isotypes and an otherwise similar order of isotype distribution (gamma 1 greater than gamma 2b greater than gamma 2a = epsilon greater than or equal to alpha) as in controls, suggests that a hyperresponsive, but less mature IgD- B cell population is selectively produced in the spleens of mice treated with anti-IgD from birth.

Influence of lymphokines on the anti-TNP-Ficoll response of normal and X-linked B lymphocyte-defective mice

Immunodeficient CBA/N and F1 hybrids of CBA/N X SJL or DBA/2Ha mice were induced to make an antibody response to TNP-Ficoll by i.v. injections of lymphokines together with the antigen. The best responses (up to 12,000 PFC/spleen on day 4) were obtained by repeated i.v. lymphokine injections on days 0, 1, 2, and 3. Lymphokines obtained from PHA-stimulated LBRM-33 cells were less effective than those in supernatants (SN) from cocultures of SJL lymph node and gamma-RCS lymphoma cells, although in each case 100 U IL 2 were given per injection. Similar SN injections caused two- to threefold increases in responses of nondefective F1 hybrids. Pretreatment with lymphokine before TNP-Ficoll injection had no effect. Additional injection of monoclonal anti-IgD decreased the effect of lymphokine. Responses to TNP-Ficoll of CBA/J spleen cells were enhanced in vitro by SN as shown previously. Although responses by CBA/N spleen cells to TNP-polyacrylamide were increased by SN, however, responses to TNP-Ficoll could not be obtained with spleen cells from the xid mice in vitro.

Influence of lymphokines on the anti-TNP-Ficoll response of normal and X-linked B lymphocyte-defective mice

Immunodeficient CBA/N and F1 hybrids of CBA/N X SJL or DBA/2Ha mice were induced to make an antibody response to TNP-Ficoll by i.v. injections of lymphokines together with the antigen. The best responses (up to 12,000 PFC/spleen on day 4) were obtained by repeated i.v. lymphokine injections on days 0, 1, 2, and 3. Lymphokines obtained from PHA-stimulated LBRM-33 cells were less effective than those in supernatants (SN) from cocultures of SJL lymph node and gamma-RCS lymphoma cells, although in each case 100 U IL 2 were given per injection. Similar SN injections caused two- to threefold increases in responses of nondefective F1 hybrids. Pretreatment with lymphokine before TNP-Ficoll injection had no effect. Additional injection of monoclonal anti-IgD decreased the effect of lymphokine. Responses to TNP-Ficoll of CBA/J spleen cells were enhanced in vitro by SN as shown previously. Although responses by CBA/N spleen cells to TNP-polyacrylamide were increased by SN, however, responses to TNP-Ficoll could not be obtained with spleen cells from the xid mice in vitro.

Cell surface phenotype of lymphoid cells from normal mice and mice treated with monoclonal anti-IgD from birth

Mice treated from birth with mouse monoclonal anti-IgD antibodies develop low frequencies of B cells in the spleen, a small percentage of which express very low levels of sIgD on their cell surface and extremely low frequencies of B cells in their lymph nodes, lacking sIgD entirely. However, the splenic B cells are phenotypically mature in that a high percentage of these cells express Lyb-5, indicating that the expression of sIgD is not a prerequisite for the acquisition of a mature surface antigen repertoire of B cells. In contrast, a high density of sIgM on splenic B cells is expressed, which suggests a predominance of cells with the phenotype of immature B cells and/or activated B cells. Furthermore, the spleen cells from anti-IgD-treated mice lack cells that respond to in vitro stimulation by LPS with an increase in the density of their sIa.

Cell surface phenotype of lymphoid cells from normal mice and mice treated with monoclonal anti-IgD from birth

Mice treated from birth with mouse monoclonal anti-IgD antibodies develop low frequencies of B cells in the spleen, a small percentage of which express very low levels of sIgD on their cell surface and extremely low frequencies of B cells in their lymph nodes, lacking sIgD entirely. However, the splenic B cells are phenotypically mature in that a high percentage of these cells express Lyb-5, indicating that the expression of sIgD is not a prerequisite for the acquisition of a mature surface antigen repertoire of B cells. In contrast, a high density of sIgM on splenic B cells is expressed, which suggests a predominance of cells with the phenotype of immature B cells and/or activated B cells. Furthermore, the spleen cells from anti-IgD-treated mice lack cells that respond to in vitro stimulation by LPS with an increase in the density of their sIa.

Derivation of transplantable 7,12-dimethylbenz[a]anthracene-induced chicken fibrosarcoma lines: differences in metastasizing properties and organ specificity

Several transplantable 7,12-dimethylbenz[a]anthracene-induced SC chicken fibrosarcoma (CHCT-NYU) lines were studied for their ability to grow in internal organs after iv injection (artificial metastases) into 1- to 3-week-old chickens. Some tumor lines were recently derived, whereas others were studied after many serial subcutaneous transplantations. STriking similarities as well as differences were found between tumor lines' ability to grow in various organs. Artificial metastases were seen primarily in the stomach, pancreas, lungs, heart, and muscle, and occasionally also in the kidneys and in the liver. Agammaglobulinemic recipients showed more extensive organ involvement than normal recipients of the same age. Whole-body gamma-irradation also enhanced the incidence of artificial metastases, particularly in lungs. Antibody from the serum of a primary tumor-bearing host reduced the growth of the corresponding tumor in many organs. The metastatic pattern of line CHCT-NYU4 was a relatively stable property, since there was little difference in the internal localization of these tumor cells studied before and after 15 serial subcutaneous transplants. However, intravenous transplantation of tumor cells from line CHCT-NYU4 taken from the liver, lungs, and pancreas of a single recipient established sublines with changes in organ specificity. After a few such serial transplants of liver-derived tumor, a line was derived that grew virtually in the liver alone. A subline with preference for growth in lungs was also obtained, but its ability to grow in the pancreas persisted. A pancreas-derived tumor line also grew in the liver and lungs. Subcutaneous transplants of tissue fragments of the lung-derived tumor line caused the appearance of spontaneous metastases in lungs. The incidence of spontaneous metastases with the lung-derived line was much greater than that with the liver-derived line or with the original CHCT-NYU4 line.