[Late onset immunodeficiency with hypo-IgG and hyper-IgM, T CD4+ lymphocytopenia and vitiligo]

The Authors report the clinical case of a patient with a deficit of humoral immunity who developed infections since puberty. The serum levels of IgG and IgA decreased progressively in the fourth decade of life, while serum IgM increased. Moreover, the patient developed a marked CD4+ T lymphocytopenia and a meager B lymphocytopenia, vitiligo, positivity for anti-SSA/Ro autoantibodies and granulomatous phlogosis of the knee. The heterogeneity of the clinical and laboratory data suggests that this patient might present an overlap immunodeficiency syndrome with some of the clinical and immunological features typical of the hyper-IgM syndrome (in the X-linked or autosomal forms) and others that can be referred to a nosologically distinct humoral immunodeficiency such as the common variable immunodeficiency.

Chemiluminescence activity in whole blood phagocytes of dogs naturally infected with Leishmania infantum

Dogs are the domestic reservoir of Leishmania infantum, a vector-borne intracellular protozoan agent of human visceral leishmaniasis. The role of polymorphonuclear leukocytes (PMNs) in the immune defence against this parasite has been poorly studied. We have investigated the function of peripheral blood PMNs in naive beagle dogs that have been naturally exposed to phlebotomine vectors in an area highly endemic for canine leishmaniasis, and found infected by Leishmania at the end of the transmission season. Whole blood phagocyte oxidative metabolism was assessed by a rapid method that determines a luminol-amplified chemiluminescence (CL) emission. This was evaluated using either a soluble stimulant, phorbol mirystate acetate (PMA), or phagocytic stimuli, such as zymosan unopsonized (ZYM) or opsonized with autologous serum (OPZ). In blood samples taken 2 months after exposure to Leishmania transmission, data on CL emission revealed a significant decrease of reactive oxygen intermediates (ROI) production in the presence of both PMA and ZYM, compared with blood samples obtained from dogs before exposure. On the contrary, no variations in CL emission were detected in presence of OPZ. Our data indicate that immunological changes occur early in canine leishmaniasis and confirm that the role of PMNs and their products need to be clarified.

Early suppression of lymphoproliferative response in dogs with natural infection by Leishmania infantum

Dogs are the domestic reservoirs of zoonotic visceral leishmaniasis caused by Leishmania infantum. Early detection of canine infections evolving to clinically patent disease may be important to leishmaniasis control. In this study we firstly investigated the peripheral blood mononuclear cell (PBMC) response to leishmanial antigens and to polyclonal activators concanavalin A, phytohemagglutinin and pokeweed mitogen, of mixed-breed dogs with natural L. infantum infection, either in presymptomatic or in patent disease condition, compared to healthy animals. Leishmania antigens did not induce a clear proliferative response in any of the animals examined. Furthermore, mitogen-induced lymphocyte proliferation was found strongly reduced not only in symptomatic, but also in presymptomatic dogs suggesting that the cell-mediated immunity is suppressed in progressive canine leishmaniasis. To test this finding, naive Beagle dogs were exposed to natural L. infantum infection in a highly endemic area of southern Italy. Two to 10 months after exposure all dogs were found to be infected by Leishmania, and on month 2 of exposure they all showed a significant reduction in PBMC activation by mitogens. Our results indicate that suppression of the lymphoproliferative response is a common occurrence in dogs already at the beginning of an established leishmanial infection.

Functional characteristics of cord blood T lymphocytes after lectin and anti-CD3 stimulation. Differences in the way T cells express activation molecules and proliferate

Newborns are more susceptible than adults to infections, which suggests a relative immaturity of the immune system early after birth. Cord blood T cells differ significantly both in surface phenotype and function from adult T cells. We examined the proliferation and expression of activation molecules by lymphocytes isolated from umbilical cord blood or peripheral blood of adults. The lymphocytes were cultured for 5 days in the presence of phytohemagglutinin, concanavalin A, or anti-CD3 monoclonal antibody. Cord blood T cells expressed the CD45RA molecule, while a low proportion expressed the RO isoform, a marker of primed or activated lymphocytes. Furthermore, more than 95% of neonatal lymphocytes bear the CD38 molecule, but do not express the CD57 molecule. After stimulation by phytohemagglutinin or concanavalin A, the lymphocytes from newborns were activated and proliferated as efficiently as adult T cells. Anti-CD3 did not cause neonatal lymphocytes to proliferate, but these cells expressed activation molecules, such as HLA-DR antigens and the receptor for interleukin-2 and transferrin. The relevance of these findings to tolerance induction in immature cord blood T cells is discussed.

Inhibition of interleukin-1 release and activity by the rat seminal vesicle protein SV-IV

SV-IV, a 9.8-kd protein isolated from rat seminal vesicle secretion, has been shown to have strong non-species-specific immunosuppressive, anti-inflammatory, antithrombotic, and antiphospholipase A2 properties. The present investigation was undertaken to determine the mechanism of action of its immunosuppressive effects. It was found that SV-IV is a potent inhibitor of interleukin-1 (IL-1) release from lipopolysaccharide (LPS)-activated human adherent monocytes and an effective inhibitor of IL-1-induced thymocyte proliferation. The ability of SV-IV to form a noncovalent dimeric association with IL-1 alpha but not with IL-1 beta, its ability to induce a marked decrease of IL-1 binding to its own receptors on the thymocyte surface, and its capacity to bind specifically to the macrophage plasma membrane might play an important role in the molecular mechanism of these inhibitory effects.

On the record, off the hook. Paperwork protects tax status

Meeting minutes of Section 501(c)(3) organizations are one of the first places the Internal Revenue Service, the state attorney general, and others will look in trying to determine whether the board of directors is governing the corporation's operations and activities in conformance with tax-exemption rules and whether board members are properly fulfilling their corporate fiduciary duties. Because such minutes reflect deliberations and actions that took place at board meetings, minutes provide a record of circumstances surrounding significant corporate decisions--decisions the IRS and others may choose to question. An organization trying to maintain its tax-exempt status can further its cause by making sure that meeting discussions (and minutes), as well as backup documentation, include all pertinent information. The tax-exempt organization should take special care when drafting minutes regarding deliberations and actions pertaining to transactions that prompt close IRS scrutiny. For example, with joint ventures, corporate minutes should reflect that the exempt organization's board based its decision to enter into the joint venture primarily on the venture's investment value and/or its value in achieving exempt purposes--not the venture's benefit to the non-exempt party.

Effects of a crystalline silica on antibody production to T-dependent and T-independent antigens in Balb/c mice

A crystalline silica (standard quartz DQ12 with particle size less than 5 micrometers) is able to stimulate in Balb/c mice the production of antibodies of various isotypes to the T-dependent antigen trinitrophenylated keyhole limpet hemocyanin. Under the same experimental conditions silica was not able to stimulate antibody response to the T-independent antigen trinitrophenylated Ficoll. These results support the possibility that adjuvanticity of silica is correlated to its effects on one or more of the various functions carried out by macrophages on immune responses.

Adjuvant effects of a crystalline silica on IgE and IgG1 antibody production in mice and their prevention by the macrophage stabilizer poly-2-vinylpyridine N-oxide

A crystalline silica (standard quartz DQ12 with particle size less than 5 microns) is able to stimulate in Balb/c mice the production of IgE and IgG1 antibody to a single 1-microgram dose of ovalbumin. The adjuvant effects of silica on both IgE and IgG1 antibody production are prevented by pretreatment of animals with poly-2-vinylpyridine N-oxide, a polymer that protects macrophages from the well-documented toxic effects of silica. These results indicate that adjuvanticity of silica is, at least partly, correlated to the damage induced on macrophages.

Adjuvant effects of iota, kappa, and lambda carrageenans on antibody production in BALB/c mice

Carrageenan, in its three fractionated forms iota, kappa and lambda, is able to stimulate in BALB/c mice the production of IgE, IgGl and those antibodies producing passive hemagglutination to ovalbumin. The adjuvant effect of carrageenan is more evident in the secondary response, and the iota form is more effective than the kappa and the lambda forms. The data are compatible with the possibility that adjuvanticity of carrageenan can be, at least partly, correlated to its antimacrophage activity.

Adjuvant effects of amorphous silica and of aluminium hydroxide on IgE and IgG1 antibody production in different inbred mouse strains

The adjuvant effects of an amorphous silica (Aerosil) and of A1(OH)3 on primary and secondary IgE and IgG1 immune responses to small doses of OA were studied comparatively in BALB/c, C57BL, DBA/1, AKR, DBA/2 and SJL inbred mouse strains. During the primary response, all mouse strains produced both IgG1 and IgE antibodies when antigen was given with A1(OH)3, whereas only DBA/1, BALB/c and DBA/2 mice produced IgG1 and/or IgE antibodies when Aerosil was used as the adjuvant. A booster effect, higher than that obtained by A1(OH)3, was induced by Aerosil in all mouse strains. The adjuvant effect of Aerosil was more selectively directed to the production of IgE antibody.

Further studies on the adjuvant effect of silica on IgE antibody production in mice

The effects of amorphous silica (Aerosil) and of aluminium hydroxide on anti-DNP IgE antibody production were studied in Swiss mice preimmunized with Ascaris protein and then challenged 7 days later with DNP-ASC. Aerosil exerted an adjuvant effect especially when it was injected together with the DNP-ASC conjugate. Al(OH)3 had a weaker adjuvant effect than that produced by Aerosil and then only when it was injected with the DNP-ASC conjugate. Al(OH)3 given with Ascaris extract 7 days before complete antigen had an inhibitory effect on the anti-DNP IgE antibody production.

Persistent and boosterable IgE antibody production in mice injected with low doses of ovalbumin and silica

The results of the present experiments show that Aerosil, an amorphous submicroscopic silica, is able to stimulate in Swiss outbred mice the production of IgE antibodies to a single 1 microgram dose of Ovalbumin (OA) in experimental conditions in which detectable IgG1 antibodies were not produced. The production of IgE anti-OA antibodies stimulated by silica was persistent for a least 4 months, and demonstrated a secondary stimulation. Neither IgE nor IgG1 anti-OA antibodies were demonstrable when mice were immunized with OA alone or OA with aluminum hydroxide.

Adjuvant effect of amorphous silica on the immune response to various antigens in guinea pigs

The adjuvant effect of a subcutaneously injected amorphous silica (Aerosil) to various antigens was studied in guinea pigs. It was demonstrated that silica is able to enhance the humoral immune response to particulate and soluble antigens widely differing in molecular weight and that, in the system employed, adsorption of antigen on silica particles is not absolutely required for its adjuvanticity.

Antigenic properties of mono-dinitrophenyl-derivatives of bacitracin A in guinea-pigs

The immunogenicity of the three mono-DNP-derivatives of bacitracin A as compared with the immunogenicity of the tri-DNP-derivative of bacitracin and of bacitracin itself was investigated in randomly bred guinea-pigs. PCA and an in vitro binding assay (a modified Farr technique) were both employed for antibody detection. All of the DNP-derivatives were able to stimulate formation of anti-DNP antibodies. Mono-DNP(ornithine)-bacitracin and tri-DNP-bacitracin induced antibody production in almost all the animals; mono-DNP(histidine)-bacitracin and mono-DNP(isoleucine)-bacitracin induced antibodies in only one-half and one-fifth of the animals, respectively. No antibodies against bacitracin could be detected in animals injected with this polypeptide or with its DNP-derivatives.

Investigation by PCA of the relative reactivities of the anti-DNP-bacitracin antibodies for each of the mono-DNP-derivatives of bacitracin revealed that different populations of antibodies are elicited by each of these substances. Specificity extending to the amino acid on which the DNP group is attached would appear to be present in the populations of antibodies elicited by both mono-DNP(ornithine)-bacitracin and mono-DNP(isoleucine)-bacitracin. Additional evidence would indicate that the specificity of the anti-DNP-bacitracin antibodies may extend beyond the DNP-amino acid determinant.