Cytokine-induced changes in the leukon

Cytokines are regulatory peptides, produced by virtually every nucleated cell type in the body, that have pleiotropic effects on hematopoietic, lymphoid, and other cell types. Cytokines usually act locally as autocrine or paracrine cellular signals intended to maintain local homeostasis but in disease states can spill over into the circulation to initiate systemic reactions. The systemic administration of high doses of recombinant cytokines is associated with a multitude of pharmacologic and toxicologic effects, frequently involving the hemolymphopoietic system. These effects may represent direct or indirect pharmacologic or hyperpharmacologic activity or may represent toxicity. The objective of this review is to present the general types of hemolymphopoietic changes associated with cytokine administration to animals and to provide examples of cytokine-induced effects on the hemolymphopoietic system.

Effects of hypothyroidism with treatment of an anti-thyroid drug, propylthiouracil on immune responses in chickens

The effect of a wide range of doses of propylthiouracil (PTU, 0.01-5%) on the immune responses of young male chickens was examined. One-day-old chickens were rendered hypothyroid by PTU supplemented in the feed for 4 weeks. At all doses PTU treatment caused a significant dose-related reduction in body weight (except at 0.01%) and in relative lymphoid organ weights. Skin response to phytohemagglutinin (PHA) was significantly greater in the chickens treated with low doses of PTU (0.01-0.1%) and significantly less in the chickens treated with high doses of PTU (1.5-5%) than that in control chickens. Number of splenic plaque forming cells (PFC) to sheep red blood cells (SRBC) was significantly increased in the chickens treated with low doses of PTU. Concentrations of serum 3,3',5-triiodothyronine (T3) and thyroxin (T4) were significantly lower in the chickens treated with all doses of PTU. Addition of T3 to the feed supplemented with 0.01% PTU replaced the serum T3 concentration and reduced the skin response to PHA and the number of the splenic PFC. These data confirm our previous observations that a low dose of PTU enhances and a high dose suppresses the immune responses of young male chickens.

Modulation of lymphohematopoiesis in long-term cultures by gamma interferon: direct and indirect action on lymphoid and stromal cells

Gamma interferon (IFN-gamma) is the product of multiple cell types within the bone marrow microenvironment and has been demonstrated to act as a potent inhibitor of myelopoiesis in vitro and in vivo. The action of this cytokine on lymphohematopoiesis has now been examined on both long-term bone marrow cultures and representative cloned cellular components of the bone marrow microenvironment. In myelopoietic (Dexter) cultures, the half maximal inhibitory concentration of IFN-gamma was between 1 and 10 U/mL. In comparable lymphopoietic (Whitlock/Witte) cultures, IFN-gamma inhibited the production of B-lineage lymphoid cells with a half maximal effective concentration of less than 1 U/mL. In a clonal assay for pre-B cells, IFN-gamma inhibited colony formation with a half maximal concentration of 1 to 5 U/mL. Not all B-lineage lymphoid cells displayed the same sensitivity, however. Growth of the IL-7-dependent B cell line (2E8) in methylcellulose assays was unaffected by IFN-gamma while the replication of other lymphoid lines was partially or completely inhibited. IFN-gamma induced the expression of cell surface proteins (MHC Class I and II) on both B-lineage cells and stromal cells. In cloned stromal cell lines, IFN-gamma increased the steady state mRNA levels for the cytokines interleukin-6 (IL-6) and JE, a member of the IL-8 family. These data indicate that IFN-gamma acts within the lymphohematopoietic microenvironment through both direct and indirect actions on the hemopoietic and stromal cell populations.

Subacute immunotoxicity study of formaldehyde in male rats

Immune functions were examined in male rats following 28 day oral administration of formaldehyde by gastric tube at dose levels of 0, 20, 40, and 80 mg/kg. Routine parameters examined included hematology, clinical chemistry, and body, thymus, kidney, and liver weights. In addition, cellularity of spleen and lymph nodes, histology of spleen, thymus, lymph nodes, liver kidney, small and large intestines, and histochemistry of spleen and lymph nodes were evaluated. Immune parameters evaluated included serum hemagglutinin antibody response; antibody plaque forming cell response to sheep erythrocytes (lymphocyte-dependent antigen); microbicidal activity of Candida albicans; and phagocytic activity by adhesion of microspheric hydrophilic synthetic particles to leukocyte cell membrane. Body weights were slightly decreased at high dose level (80 mg/kg). The difference was significant when compared to the controls. The lymph node weights were significantly increased in rats receiving formaldehyde. The cellularity of lymphoid organs was not influenced after 28 day exposure to formaldehyde.

[The effect of cytostatic and immunomodulator therapy on the morphology of the tumor and lymphoid organs and on the count of large granular lymphocytes in the blood of mice with Lewis carcinoma]

Effects of separate and combined therapy with nitrosomethylurea (NMU), methotrexate thymalin, and reaferon on tumor, thymus and spleen morphology as well as the content of large granular lymphocytes in blood were studied in mice with Lewis lung carcinoma. The study revealed different effects of methotrexate and NMU on tumor and lymphoid organs. The direct NMU damage to tumor was accompanied by a suppression of host immune system which was only slightly reversed with immunomodulators. The cytotoxic antitumor effect of methotrexate was probably related also with the stimulation of host immune system, its cells in turn affecting the size of proliferating tumor fraction.

The effect of cyclophosphamide treatment on lymphocyte subsets in the nonobese diabetic mouse: a comparison of various lymphoid organs

The nonobese diabetic (NOD) mouse is a model for human Type 1 diabetes mellitus. Pancreatic beta-cell destruction in NOD mice is mediated by an autoimmune process which can be accelerated by cyclophosphamide (CP). We studied the phenotype of lymphocytes from central, peripheral and regional lymphoid tissues in prediabetic NOD and C3H mice before and after a single large dose of CP. All lymphoid organs showed a greatly diminished cell number and most alterations appeared early after CP and were transient, but an aggressive insulitis was not seen in NOD mice until 14 d after injection. The pancreatic islets in C3H mice remained intact and were not infiltrated. NOD female mice, which are most prone to spontaneous and CP-induced diabetes, exhibited the most unusual lymphoid kinetics after treatment with CP. Their thymus and spleen showed the least relative drop in total cell number and the most rapid rate of recovery. The thymus of these mice was also found to have an increased proportion of CD3+ thymocytes while CD4/CD8 double positive thymocytes decreased 7 d after CP. At 14 d after CP the number of IL-2R+ thymocytes had surpassed that of normal levels. The most dramatic observation was the rapid recovery and overshoot in the number of pancreatic lymph node cells of female NOD mice which coincided with aggressive insulitis.

Protection by Ca2+ channel blockers (nifedipine, diltiazem and verapamil) against the toxicity of oxidized low density lipoprotein to cultured lymphoid cells

1. Ca2+ channel blockers from 3 different chemical classes (diltiazem, verapamil and nifedipine) were compared in their ability to inhibit low density lipoprotein (LDL) oxidation and to protect cells directly against the cytotoxicity of oxidized LDL. 2. LDL oxidation promoted either by u.v. radiations or by copper ions was inhibited by nifedipine (IC50 of 10 +/- 2 and 4 +/- 0.5 mumol l-1, respectively) whereas diltiazem and verapamil were only poorly active or completely ineffective. As expected, LDL protected from oxidation by nifedipine (nifedipine/oxidized LDL) were much less cytotoxic than (unprotected) oxidized LDL (or than LDL oxidized in the presence of diltiazem or verapamil). The cytotoxic effect correlated well with the lipid peroxidation derivatives measured as the thiobarbituric acid reactive substances (TBARS) content of LDL oxidized in the presence of Ca2+ channel blockers, which suggests that the antioxidant effect of Ca2+ channel blockers protected cells indirectly from the cytotoxic effect of oxidized LDL. 3. Nifedipine also exhibited a direct cytoprotective effect against the cytotoxicity of oxidized LDL as demonstrated by incubating cells in the presence of unprotected oxidized LDL and nifedipine (IC50 of 1 +/- 0.2 mumol l-1), whereas diltiazem and verapamil did not exhibit any significant protective effect. At the concentrations used, the protective effect of nifedipine was not due to inhibition of LDL uptake by Ca2+ channel blockers. 4. The direct protective activity of nifedipine is probably unrelated to its antioxidant properties since it did not inhibit the cellular TBARS evoked by oxidized LDL taken up by the cells, in contrast to vitamin E. 5. Nifedipine (and diltiazem to a lesser extent) inhibited the slow [Ca2+]J rise induced by oxidized LDL and the subsequent cytotoxicity.6. It is proposed that relatively high concentrations of nifedipine (unlike diltiazem and verapamil)protect cultured lymphoid cells against the cytotoxicity of oxidized LDL by two different mechanisms:(i) an antioxidant effect inhibiting LDL oxidation (outside the cell); (ii) a direct cytoprotective effect (at lower concentrations), the mechanism of which is unknown. These data could explain in part the mechanism of action of nifedipine in the prevention of cellular damage potentially involved in atherogenesis.

Activation of omental milky spots and milky spot macrophages by intraperitoneal administration of a streptococcal preparation, OK-432

Omental milky spots are omentum-associated lymphoid tissues that cede peritoneal macrophages and participate in the immunity of the peritoneal cavity. We studied the changing surface features of milky spots and milky spot macrophages of Wistar rats, following the i.p. administration of OK-432, a killed streptococcal preparation (1 Klinische Einheit (unit) in 5 ml of phosphate-buffered saline) by the use of scanning electron microscopy. OK-432-activated macrophages demonstrated marked surface membrane activity and migrated through the stomata of the milky spot into the peritoneal cavity. The characteristic features of activated milky spots and milky spot macrophages were noted as early as 3 h following the administration of OK-432, and continued to be observed until 7 days after the injection. By 14 days after the injection, the structural integrity of the milky spot was partially lost. The activation of milky spots and milky spot macrophages by OK-432 provides a convenient in vivo system for the monitoring and study of i.p. cellular events.

Systemic administration of recombinant interleukin-6 in mice induces proliferation of lymphoid cells in vivo

Interleukin-6 (IL-6) is a pleiotropic cytokine and has been shown to support the growth of T and B lymphocytes in the presence of mitogens in vitro. IL-6 can induce human natural killer (NK) and interleukin-2 (IL-2)-induced lymphokine-activated killer cell (LAK) activity in vitro. It can also mediate antitumor effects in various murine models. In order to understand the mechanism of in vivo action, we have investigated the proliferation of lymphoid cells in vivo and the effects on NK, and LAK cell activities in response to IL-6 administration in mice. In vivo proliferation was measured by labeling the DNA of dividing cells with [125I]iodo-2'-deoxyuridine. C57BL/6 mice were injected ip with either IL-6 or HBSS control two times a day for 3 days and in vivo proliferation was measured. For comparative purpose IL-2 was administered and in vivo effects were analyzed. IL-6 caused significant proliferation of cells mainly in the spleen, while, IL-2 caused proliferation in the lungs, liver, spleen, and kidneys. Pretreatment irradiation (500 rad) of mice abrogated the IL-6-induced proliferation indicating radiosensitive cells are involved. Furthermore, in vivo proliferation was not observed in young nude mice treated with IL-6. To investigate whether the proliferating cells were cytotoxic, we tested for LAK (vs. fresh MCA-102 tumor targets) and NK (vs. Yac-1 tumor targets) activities in the organs of mice treated with IL-6 or IL-2 by 4 h 51Cr-release assay. IL-2 administration induced the generation of LAK activity and increased NK cytotoxicity in various organs, but IL-6 had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulatory effects of metanil yellow on immunity in rodents

Pathomorphological and immunological studies were carried out on rodents following oral administration of 0, 0.1, 0.25 and 0.5% (w/w) metanil yellow, mixed in diet, for 30 days. No significant change in hematologic parameters and histologic architecture of liver, kidney, mesenteric lymph node, thymus and urinary bladder was observed except for mild desquamation of intestinal villi and moderate changes in Peyer's patches of small intestine with higher doses. Among immunological parameters, significant enhancement in the primary humoral immune response (anti-SRBC IgM plaque forming cells of spleen) was observed with the lowest dose of metanil yellow while higher doses produced opposing effects. An elevated cutaneous delayed type hypersensitivity (DTH) reaction to SRBC was seen in 0.1% metanil yellow treated animals but higher doses did not influence the reaction. The treatment also caused changes in functional capabilities of macrophages. Although these immune alterations could hardly influence the local immunity of gut, as measured by the capacity of animals to cause rejection of Nippostrongylus brasiliensis parasite, the potential to modulate the immunity in general by metanil yellow however assumes considerable biological significance.

[The status of the lymphoid organs in the maternal organism as a reflection of the efficacy of correcting venous congestion during pregnancy in rats]

Under study was the influence of polyphenolic complexes of great burnet and venoruton upon the thymus, spleen, iliac lymph nodes of the uterus area in experimental phlebo-occlusion syndrome of pregnant rats. The data obtained show the changes of the drainage function of the lymphatic system under the influence of the drugs under study, certain reaction of T- and B- dependent zones of the central (thymus) and peripheral lymphoid organs. The structural-functional shifts had positive effects upon the fetus state. The action of polyphenols of great burnet is more effective as compared with venoruton.

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on blood and spleen natural killer (NK) cell activity in the mouse

The immunotoxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were studied in male A/J mice after a loading dose of 5 micrograms TCDD/kg body wt. followed by 3 weekly maintenance doses of 1.42 micrograms TCDD/kg b.w. administered intraperitoneally. Tissue samples and immune cells were prepared on two occasions, i.e. on days 28 and 120 after the first injection of TCDD. This dose of TCDD evoked classical histological signs of liver damage and lipid accumulation, as well as thymic atrophy. Red (RBC) blood cell counts were significantly lowered in the TCDD group on day 28, but were normal on day 120. White (WBC) blood cell counts were normal in the TCDD group. Natural killer (NK) cell activity increased 3.4-fold (P less than 0.01) and 2.2-fold (P less than 0.01) in the blood and spleen, respectively, after 28 days, and these effects persisted on day 120. The increased NK-cell activity occurred concomitantly with a decreased proliferative response of spleen lymphocytes to the T-cell mitogen concanavalin A after both 28 (65%) and 120 days (58%). The proliferative response of spleen cells to the B-cell mitogen lipopolysaccharide seemed, however, unaffected. We have thus shown for the first time that TCDD induces an increased activity of NK cells that occurs simultaneously in the blood and spleen. This effect may indicate a general compensatory activation of the body's defences brought about by disturbances in the function of other arms of the immune system.

Histopathologic and immunohistochemical changes in gut-associated lymphoid tissues after treatment of rabbits with dexamethasone

Corticosteroids cause impaired cell-mediated immunity which may encourage development of gastrointestinal and respiratory infections. In order to better understand the effects of corticosteroids on gastrointestinal immunity, immunological and histological changes in gut-associated lymphoid tissues were examined after intravenous administration of dexamethasone to rabbits. In treated animals, lymphoid domes and follicles were considerably reduced in size, and the dome epithelial layer was markedly depleted of M cells and lymphocytes. There were numerous open lesions at the luminal surface of dome epithelium, consistent with necrosis of M cells, and a striking depletion of follicular B cells in treated animals. These immunologic and histologic effects of corticosteroids could have found profound, deleterious effects on mucosal immune responses and host resistance to microbial infections.

DMBA-induced cytotoxicity in lymphoid and nonlymphoid organs of B6C3F1 mice: relation of cell death to target cell intracellular calcium and DNA damage

The purpose of these studies was to evaluate the effects of 7,12-dimethylbenz[a]anthracene (DMBA) on intracellular free Ca2+ and DNA fragmentation in lymphoid cells obtained from the spleen, thymus, and Peyer's patches (PPs) of female B6C3F1 mice. Previous studies in our laboratories have shown that DMBA is cytotoxic to these lymphoid organs and that calcium homeostasis may be impaired following DMBA treatment. The results of the present studies show that a daily oral 14-day exposure of mice to DMBA produced a dose-dependent decrease in the number of viable cells recovered from the spleen, PPs, and thymus. Intracellular levels of Ca2+ were elevated in the spleen and PPs of mice receiving 140 mg/kg of DMBA. Extensive DNA fragmentation was detected in cells obtained from the spleen and PPs, as well as from the thymus. The thymus and PPs demonstrated DNA fragmentation at significantly lower doses of DMBA (42 mg/kg) than did the spleen (140 mg/kg). While cells obtained from the thymus did not demonstrate an elevation in Ca2+ produced by DMBA, in vitro exposure of isolated thymocytes to 3-30 microM DMBA for 4 hr produced significant elevation of intracellular Ca2+. A "ladder-like" pattern of DNA fragmentation was seen by agarose gel electrophoresis of DNA obtained from thymus cells treated with DMBA in vitro, suggesting DNA degradation by endonucleases. Collectively, these studies suggest that DMBA produces lymphotoxicity through an apoptosis-like mechanism involving fragmentation of genomic DNA by Ca(2+)-activated enzymes.

Synthesis and biological activity of uronic acid analogues of 2-5A[5'-O-triphosphoryladenylyl(2----5')adenylyl-(2'----5')adenosine]

The oligonucleotide ppp5'A2'p5'A2'p5'A, known as 2-5A, is a potent translational inhibitor involved in some aspects of interferon action. To explore the specific function of the charged 5'-triphosphate moiety, we prepared a series of congeners in which the 5' region was hypermodified. Thus, uronic acid derivatives were substituted for the 5' terminal adenosine residue of 2-5A. Compounds 9, 10, 11 and 12 carried adenosine 5'-uronic acid, ethyl adenosine 5'-uronate, adenosine 5'-uronamide, and adenosine 5'-(N-ethyl)uronamide, respectively, in place of the 5' terminal adenosine triphosphate moiety of 2-5A. While all the analogues showed some weak interaction with the 2-5A-dependent endonuclease (RNase L), compound 9 showed the strongest binding ability, and while unable to activate the mouse RNase L, could activate human RNase at a concentration 100-fold greater than that required for the parent 2-5A. This result suggests that the function of the 5'(poly)phosphate moiety of 2-5A may be fulfilled by some other anionic moiety.

Effects of cigarette smoke on the antibody responses to thymic independent antigens from different lymphoid tissues of mice

The influence of cigarette smoke on the humoral immune response of mice was investigated in lymphocytes derived from the spleen, bone marrow (BM) and mesenteric lymph nodes (MLN). Mice of the DBA/2J or C57BL/6 strain were exposed to cigarette smoke of a standard research cigarette, 2R1, twice a day, ten puffs each in morning and afternoon for 20, 40 or 60 weeks. At the end of the smoking period, animals were immunized intraperitoneally with the thymic independent antigens polyvinyl pyrrolidone (PVP) or trinitrophenyl (TNP)-Ficoll. The antibody responses were analyzed using sheep red blood cells coated with PVP or TNP, in a plaque forming cell (PFC) assay. The results indicate a statistically significant inhibition of the antibody response induced by PVP but not by TNP-Ficoll in splenic B cells of smoke exposed mice compared to sham controls. When tested in other lymphoid organs, there was higher anti-TNP PFC response from the BM and MLN cells of smoke exposed animals compared to sham controls.

Spontaneously hypertensive rat: lymphoid depression is age dependent and mediated via a mononuclear cell subpopulation

Immune dysfunction has been reported in spontaneously hypertensive rats (SHR), particularly in mature animals with established hypertension. The current study examined the time course of development of immune dysfunction and defined its cellular basis in male SHR and control normotensive Wistar-Kyoto rats (WKY). Mitogen-induced proliferative responses in lymphoid cells obtained from induced proliferative responses in lymphoid cells obtained from SHR thymus and spleen before (age 4 wk) and during the development of (ages 8 and 12 wk) hypertension and in age-matched normotensive WKY were monitored. A 50% reduction in concanavalin A (Con A)-induced proliferative responses was seen in SHR thymocytes compared with those of WKY at 12 wk only, suggesting differences in immature T-cell populations. Con A-induced T-cell proliferative responses in splenocytes also differed between strains: greatest (as much as 8-fold) decreases were found in 12-wk-old SHR. Similar findings were obtained in splenocytes stimulated with lipopolysaccharide (LPS), indicating differences in B-cell function. Mononuclear cells depleted of their adherent cell population were prepared from SHR and WKY at 12+ wk of age and assayed for their proliferative responses to LPS and Con A. The remaining nonadherent mononuclear cells of SHR had proliferative responses equal to or greater than those of WKY. Further, when SHR splenic mononuclear cells were allowed to adhere to plastic, and the adherent fraction was co-cultured with either SHR G-10 nonadherent or unfractionated SHR splenic mononuclear cells, proliferative responses were suppressed by as much as 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Exogenous melatonin modifies the circadian rhythm but does not increase the level of some immune parameters in the chicken

The effect of daily injection of the pineal hormone melatonin and naltrexone, an opioid antagonist, on the circadian rhythm and the level of immune parameters (plaque forming cell [PFC] number, serum agglutinin titer, lymphoid gland weight, total white blood cells (WBC) and their fraction number, and serum lysozyme [LZ] content) was examined in White Leghorn cockerels and female BALB/c mice kept in LD 12:12. Animals were immunized ip with sheep red blood cells (SRBC) to stimulate their immune system. Subcutaneous injections of melatonin, naltrexone, or both drugs together were made 2 hr before the end of light, for 4 or 5 days, beginning on the day of immunization. The day following the fifth injection, chickens were sacrificed over a 24 hr period every 4 hr (experiment I) or twice daily, i.e., at the beginning of light and dark phases (experiment II). Mice were killed on the day following the fourth injection at the beginning of light, and splenic PFC number was determined (experiment III). In experiment I, the existence of the diurnal rhythm was evaluated by cosinor analysis. Melatonin injections entrained the circadian rhythm in anti-SRBC serum agglutinins, but it did not influence circadian rhythmicity in other parameters examined. The circadian rhythm in total WBC number and their fractions was entrained by naltrexone treatment. Melatonin injections did not affect either the diurnal mean of parameters examined or the weight of lymphoid organs. Splenic PFC number in chickens was diminished by both melatonin and naltrexone injections, whereas in mice it was increased by melatonin, and naltrexone antagonized that effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunomodulatory effects of gamma-HCH (Lindane) in mice

Mice were fed for 24 weeks with three different subtoxic dosages of gamma-HCH (0.012, 0.12 and 1.2 mg/kg) mixed in powdered feed. The immunological profile was assessed at an interval of one month during the entire exposure period. Both the cell mediated and humoral components of immunity showed a biphasic response characterized initially by stimulation followed by suppression in a dose dependent manner. However, gamma-HCH did not affect the functional properties of peritoneal macrophages. Histological changes in lymphoid organs were in accordance with the biphasic immunomodulatory effects of gamma-HCH.

Immune response to the Lyme spirochete Borrelia burgdorferi affected by ethanol consumption

Rats fed excessive amounts of ethanol developed marked hematologic and immunologic changes. These included a reversal of the normal lymphocyte to granulocyte ratio in the peripheral blood, lower spleen and lymph node weights and a greatly reduced capacity to express normal cell mediated immune functions, based on poor lymphocyte reactivity in vivo, and in vitro to T and B cell mitogens and borrelial antigens shortly after primary immunization with the bacterial spirochete, Borrelia burgdorferi. Further evidence for impaired immune function caused by ethanol was based on little or no antibody response against Borrelia in rats following in vivo sensitization with B. burgdorferi incorporated in complete Freund's adjuvant. These findings provide substantial direct evidence strengthening the notion that high levels of ethanol ingestion adversely affect the host immune system and can interfere with the immune response to microorganisms.

[Myelotoxicity of epirubicin]

Epirubicin (pharmorubicin, India), an antitumor antibiotic of the anthracycline group, was studied in regard to its effect on peripheral blood, bone marrow and lymphoid organs (the thymus and spleen) of CBA mice after its intraperitoneal administration in a single dose equal to the MIC (7.8 mg/kg) and in a course dose (1/5 of the MIC 5 times a day). The cytogenetic impairments induced by the cytostatic were estimated on metaphase plates with the bone marrow specimens and by counting the peripheral blood erythrocytes with micronuclei (the micronuclear test). It was shown that epirubicin induced cytogenetic disturbances in the hemopoietic cells within the first 72 hours. The antibiotic had a marked reversible effect on the erythroid population and lymphoid tissues and a moderate toxic action on the granulocyte population. The antibiotic did not affect thrombocytopoiesis. The single administrations had a more pronounced and prolonged myelotoxic and lymphotropic effect.

[Immunomodulatory effect of Consupren Sol. Spofa (cyclosporin A). Preclinical study]

Consupren Spofa was demonstrated in our tests to be a distinguished immunomudulating agent. The preparation did not show any direct lymphotoxicity or myelotoxicity but it markedly influenced maturation of T lymphocytes in the thymus. When testing the functional activity of the immunity system in vivo, the inhibitory effect of Consupren Spofa was manifested only when administering a relatively larger dose of the drug with an antigenic stimulus or shortly after it, i.e., in the period of early activating processes. The use of a suitable time and dosage regimen is therefore decisive to induce an inhibitory effect. On the basis of comparative experiments it can be stated that Consupren Spofa is minimally as much effective as, or in some experiments even more effective than Sandimmun Sandoz.

Transient secretory IgA deficiency in mice after cyclophosphamide treatment

Cyclophosphamide (Cy), an alkylating agent widely used in chemotherapy of leukemia and cancer, causes a well-documented toxicity on hematopoietic and lymphoid cells. Neutropenia is thought to be the main factor involved in infectious complications following antimitotic chemotherapy. Little is known on the effects of these therapies on the mucosal associated lymphoid system which is one of the main barriers against environmental pathogenic agents. The present study examined the effects of a single administration of Cy (200 mg/kg) on murine T and B cell populations of Peyer's patches (PPs), IgA secretion in the proximal part of the small intestine, and plasma cells of the lamina propria. Cy induced in mice a transient decrease in the T and B cell populations of the PPs with a drastic fall of B cell counts and a profound decrease of intestinal IgA secretion due to a reduction of lamina propria plasma cells. This transient secretory IgA deficiency may contribute to the infectious complications following antimitotic chemotherapy.