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At least 469 records · Page 26Linked to original sources
PubMed1988

Modulated immune responsiveness associated with experimental Encephalitozoon cuniculi infection in BALB/c mice.

Spleen cell blastogenesis to mitogens and antibody responses to sheep erythrocytes (sRBC) were tested in BALB/c mice with experimental E. cuniculi infections. Blastogenesis responses of spleen cells 1 week post-infection were significantly lower than normal to T-cell mitogens (Con A and PHA) and were unchanged in response to B-cell mitogens (LPS and PWM). After 2 weeks post-infection, the responses to T cell mitogens returned to normal. Mixing spleen cells from 1-week infected mice with cells from uninfected mice failed to reveal the presence of suppressor cells. Antibody responses to sRBC were significantly slower to develop in 1 week-infected mice compared with uninfected mice or mice infected 2 weeks earlier or at the same time as sRBC challenge. Infected mice displayed splenomegaly which was most pronounced 1 week post-infection and the differential spleen cell counts revealed the presence of lymphoblasts. Lymphohyperplasia appeared to cause the splenomegaly. No shifts in the proportion of Thy 1.2+ T cells, Ig+ B cells, or esterase-positive macrophages were detected. These results indicate that the immune system in BALB/c mice is depressed early during E. cuniculi infections.

Animals↗
PubMed1988

[Effect of intra-thoracic administration of an immune modulator (OK-432) with anti-cancer drugs (ADR and MMC)].

Fourty-three patients with pleuritis carcinomatosa have been treated with an intra-thoracic administration in four distinct ways: Adriamycin alone, OK-432 alone, the combination of Adriamycin with OK-432, or the combination of Mitomycin C with OK-432. Judging from an evaluation of the subsequent chest X-rays, the prognosis of the cases which received the combination therapy of the two drugs was significantly better to that of the others. There were no significant differences between cases with primary lung cancer and those with other cancers. As for the side effects after the administration, there were no side effects, such as the trouble the renal function or liver function, other than fever and a decrease in the W.B.C.

Adjuvants, Immunologic↗
PubMed1988

Graft-versus-host reaction-induced immune modulation. I. Donor-recipient genetic disparity and the differential expression of Lyt-2, L3T4, and Ly-6 during acute reactions in the host thymus.

To investigate the effects of graft-vs-host reactions (GvHR) on cells in a central lymphoid compartment, GvHR were induced across class I/II or class II only major histocompatibility complex differences utilizing the parent into nonirradiated F1 hybrid (P----F1) model. Thymocytes were subsequently examined during the acute stage of GvHR for the expression of Lyt-2, L3T4, and Ly-6 cell surface molecules. Class I/II "suppressive" GvHR resulted in a dramatic decrease (greater than 85%) in total thymocyte numbers by 2 wk after parental cell injection. Although a dramatic decrease in the percentages of Lyt-2 (85%----30%) and L3T4 (95%----50%) expression was observed, the percentage of thymocytes expressing Ly-6 was markedly increased compared to uninjected controls (5%----greater than 80%). This increased percentage was not due solely to a selective loss of Ly-6 negative cells from the thymus, since the actual number of Ly-6 positive cells was greater in GvHR mice than in controls. Class II GvHR during the same time interval resulted in a less dramatic decrease (20 to 60%) in total thymocyte numbers. In addition, the effect on the percentages of Lyt-2 (85%----approximately 70%) and L3T4 (95%----approximately 85) expression was subtle and transient. However, intrathymic Ly-6 expression was again clearly enhanced (5%----20 to 30%). Class I/II "proliferative" or "stimulatory" GvHR differ from "suppressive" reactions in that they are characterized by stimulatory pathologic symptoms and the appearance of autoimmune abnormalities. Such GvHR were found to result in minimal alteration of total thymocyte numbers. Similarly, the percentage expression of Lyt-2 and L3T4 was marginally affected. However, the percentage of Ly-6 expression was increased from 5%----20 to 30% and thus these intrathymic lymphocyte profiles more closely resemble those of class II as compared to class I/II "suppressive" GvHR. The present findings therefore demonstrate that major histocompatibility complex differences alone do not necessarily determine the effects of GvHR on recipient thymocytes and that Ly-6 is a useful marker for the early detection of GvHR-associated immunologic events.

Animals↗
PubMed1987

Histamine type-2 receptor antagonist immune modulation. II. Cimetidine and ranitidine increase interleukin-2 production.

The effect of cimetidine and ranitidine (histamine type-2 receptor antagonists) on the production of interleukin-2 (IL-2) by mitogen-activated, normal murine spleen cells was studied in vitro. Cimetidine (10(-4) mol/L to 10(-6) mol/L) increased IL-2 production to a maximal 8.8 +/- 1.6 U (IL-2 activity), as compared with media controls of 1 U. Ranitidine (10(-4) mol/L to 10(-6) mol/L) also increased IL-2 production to a maximal 5.6 +/- 1.2 U, as compared with media controls of 1 U. The increases for both drugs were statistically significant- (p at least less than 0.03 for all doses tested). These data suggest that our previously demonstrated immunofacilitation of proliferative and cytotoxic lymphocyte responses by cimetidine was probably mediated by the presence of increased IL-2. These data further suggest that histamine type-2 receptor antagonists may have immunorestorative potential in clinical immunotherapy of IL-2 deficient states.

Animals↗
PubMed1985

The role of C1, C1-inactivator and C4 in modulating immune precipitation.

To clarify the mechanism of inhibition of immune precipitation by early components of the classical pathway of complement, aggregation of 125I-BSA-rabbit-anti-BSA antibody complexes was performed in the presence of purified C1, C1-inactivator (C1-In) and C4. C1 delayed the rate of immune precipitation in a concentration dependent manner. This phenomenon was not influenced by the presence of 0.3 mM p-nitrophenyl-p-guanidinobenzoate (NPGB) which inhibits C1 activation. The antiaggregational effect of C1 was reversed by 10 mM EDTA and by C1-In at a C1-In/C1 molar ratio of greater than or equal to 4/1. C1-In was not effective when the reaction was performed in the presence of NPGB. Thus, although the inhibitory effect of C1 on immune precipitation was not dependent upon C1 activation, the formation of C1 was required to observe the effect of C1-In. The addition of C4 to C1 did not modify the slow aggregation of complexes, even when a limiting concentration of C1 was used. C1-In and EDTA were both able to cause similar rapid precipitation of complexes prepared in the presence of C1 and C4, demonstrating that C4 did not play a significant role in delaying the precipitation reaction. However, soluble complexes prepared in the presence of C1 and C4 were specifically precipitated by the addition of excess anti-C4 antibody, attesting to the binding of C4 to immune complexes. These observations suggest that the processing of immune complexes in vivo may not be similar in different classical pathway complement deficiency states.

Animals↗
PubMed1984

The influence of classical pathway components during alternative pathway--modulated immune complex aggregation: the role of C1 INH.

Alternative pathway (AP)-triggered reactions as well as classical pathway (CP)-mediated ones, were investigated turbidimetrically and/or immune electrophoretically, either in the presence or in the absence of in situ-generated immune complexes (ICs; tetanus toxoid/human anti-tetanus toxoid-IgG; ICs of equivalence) during the early stages of reaction. Monospecific Fab'- or Fab-fragments (rabbit) were used to block the complement function in normal human serum (NHS). C1q, functionally available following the addition of ethylene-glycol-bis-(beta-aminoethyl ether), N,N'-tetraacetic acid to NHS (EGTA-NHS), was found to increase the IC aggregation, thereby producing a biological surface upon which AP-dependent proteins were deposited. The functional inhibition of C1INH caused a C1s-mediated C3 conversion irrespective of the fact whether C1s was incorporated within macromolecular C1 (NHS) or dissociated from it (EGTA-NHS), thus, in the latter case inhibiting the AP-dependent portion of turbidity. It seemed probable that C3 conversion was effected by a fluid-phase CP C3 convertase. This process, normally counteracted by C1INH, worked more efficiently in EGTA-NHS than in NHS, indicating that the C1s-mediated reactions, initiated by presently unknown mechanisms, were less extensively regulated outside of the Ca2+-dependent C1 complex. The study demonstrates that in EGTA-NHS, too, where AP-triggered reactions have usually been investigated, sections of CP activation may play an important role, especially in situations where the function of C1INH is restricted.

Antigen-Antibody Complex↗
PubMed1995

Neuropeptides modulate immune deviation induced via the anterior chamber of the eye.

Ag presentation via the anterior chamber of the eye results in a form of immune deviation termed anterior chamber-associated immune deviation (ACAID). The hallmarks of this response are the suppression of delayed-type hypersensitivity with simultaneous induction of Ab production. In this study, we examined the role of the neuropeptides vasoactive intestinal peptide (VIP) and substance P (SP) and found that the levels of these two peptides are controlled by neurogenic stimulation of the eye by light, and that these molecules determine the outcome of Ag presentation in the eye. Mice reared under diurnal conditions had VIP in the iris and ciliary body (not free in aqueous humor) and low levels of SP. Mice that were reared in the dark (or dark-adapted) did not contain detectable levels of VIP but had high levels of SP. The adaptation of diurnal mice to the dark eliminated VIP and increased SP, while adapting dark-reared mice to the diurnal cycle increased VIP and reduced SP. We then tested the hypothesis that immune reactions resulting from Ag presentation in the eye were linked to SP and VIP. We found that a VIP receptor antagonist, when injected into the eye with Ag, reversed ACAID in diurnal mice, while a SP receptor antagonist restored ACAID to dark-adapted mice. We further determined that injection of Ag or TNF-alpha induced VIP release, while SP was liberated into the aqueous humor following reexposure of dark-reared mice to light. Our results demonstrate a close linkage of intraocular immune reactions to neuropeptide levels in the eye.

Animals↗
PubMed1997

Immune modulation and sepsis.

The pathogenesis of sepsis involves not only microbial toxins but also activated host inflammatory mediators. Therefore, besides conventional antibiotic or surgical treatment of infection and supportive intensive therapy, modulating host inflammatory mediators as a conjunctive therapeutic option has been explored in the past decade. Although successful in animal models of sepsis, inhibiting host inflammatory response in human sepsis has failed to improve survival or otherwise show efficacy. Studies are needed which better describe the circumstances under which these therapies may ultimately prove successful.

Adjuvants, Immunologic↗