Specific Serum Antibody Titers Research Articles

Survival of long-lived plasma cells is independent of antigen.

Recent studies have shown that persistent specific antibody titer is provided by long-lived plasma cells (PC) which constitute a new kind of 'memory-providing cells'. In the present study, we examine the role of antigen for the long-term survival of PC and the maintenance of specific serum antibody titers. Using a novel cytometric technology, to identify and isolate antigen-specific PC, we analyzed long-lived PC of BALB/c mice, during their development (between day 1 and 10) after secondary immunization with ovalbumin (OVA) and in the phase of the established immune reaction. Most if not all OVA-specific PC were generated within a few days after immunization. Within approximately 3 weeks, they matured, as indicated by down-regulation of expression of MHC class II. These PC are long lived and located in spleen and bone marrow. Upon adoptive transfer, OVA-specific PC from bone marrow, but not memory B cells, conferred specific and long-lasting antibody titers to antigen-free IgH syngeneic recipients. In response to antigenic challenge, new OVA-specific antibody-secreting cells were generated from transferred memory B cells. Antibody secretion by long-lived PC was not affected. Our results confirm that persistent antibody titers are provided by long-lived PC, independent of memory B cells and demonstrate that this humoral memory is inert to antigen.

Superinfection with helicobacter hepaticus does not alter the natural course of colitis in IL-10 deficient mice

IL-10 deficient mice (IL-10 -/-) spontaneously develop colitis when housed in microisolators (SPF housing). The severity and rate of disease onset is aggravated when these mice are maintained in conventional housing, suggesting that gastrointestinal flora contribute to the inflammation. Recent reports have implicated intestinal Helicobacter species in the development of colitis in immunodeficient mice. We investigated whether H. hepaticus infection can promote the development of colitis in IL-10 / mice. Clinical signs of colitis in SPF-housed IL-10 /mice on a C57BL/10 background (weight loss, blood in the stool) are observed at 12 weeks of age and histological inflammation (crypt abscesses, ulcerations, skip lesions, transmural infiltration, epithelial hyperplasia) is maximal at 18-20 weeks. IL-104were superinfected with 107 bacteria by oral gavage at 12 weeks of age and examined for occult blood in the feces, Helicobacter specific serum antibody titers and microscopic inflammation at 24 weeks. All naive and superinfected mice had evidence of fecal blood. Rectal prolapse was observed in 50% of the animals in both groups. Histological scoring for tissue damage and degree of inflammation demonstrated severe focal inflammation in all animals. No significant differences were noted between groups. These data demonstrate that superinfection with H. hepaticus does not increase the rate of disease onset, exacerbate the severity of inflammation, or modify the course of the colitis. It remains to be determined whether intestinal Helicobacter species play a role in the initiation or propagation Of colitis.

Simulation of control strategies for the cattle tick Boophilus microplus employing vaccination with a recombinant Bm86 antigen preparation

Current strategies for the control of the cattle tick Boophilus microplus include the use of chemicals as the principal control method. These methods, however, have met with partially successful results. The recent development of immunological methods for the control of the cattle tick has opened new possibilities for the design of control strategies. Employing the results obtained by us in experiments testing the effect of vaccination with the recombinant vaccine, Gavac ™ (Heber Biotec S.A.), on tick populations, we have developed a model to evaluate, through a computer program, the efficacy of the vaccine as a control method. The action of the vaccine on the control of tick populations was simulated and the specific serum antibody titers required to decrease the tick population in the field were calculated. The specific serum antibody titer required to decrease the tick population in the field after the first vaccination scheme was found to be ≥ 57 200 and the antibody titer required to maintain this effect when the vaccine is already acting and after successive revaccinations was found to be ≥ 27 500. Considerations about revaccination schemes and combination between vaccination and acaricide treatments as possible control strategies are discussed.

Delayed hypersensitivity to Trypanosoma cruzi antigen. I -- Experimental study in rabbits

Delayed-type skin hypersensitivity in rabbits infected with homologous or heterologous T. cruzi has been elicited upon injection of 50 micrograms of protein in the T12E antigen derived from a parasite clone. The specificity of this reaction was indicated by absence of skin reactivity in control rabbits that received same quantity of antigen. Also, the intradermal injection of the antigen in five occasions in control rabbits neither induced seroconversion nor shifted their skin sensitiveness. On the other hand, chagasic rabbits that underwent a series of five skin testings one week apart, did not alter the intensity of the skin reactivity, and their specific serum antibody titers remained similarly high. Of interest, the ECG patterns remained unchanged after a series of five skin testings in control and in chagasic rabbits. This study shows that the T12E antigen might be an useful tool for diagnosing T. cruzi infections, besides serving as an immunologic marker for morbidity in Chagas' disease.

Mitogen and antigen induced B and T cell responses of peripheral blood mononuclear cells from the harbour seal (Phoca vitulina).

In vitro assays were developed for studies concerning the functioning of the immune system of the harbour seal (Phoca vitulina). Proliferative responses of peripheral blood mononuclear cells (PBMC) were measured after stimulation with different concentrations of the mitogens concanavalin A (Con A), pokeweed mitogen (PWM), phytohaemagglutinin (PHA) or lipopolysaccharide from Salmonella typhimurium (LPS). Con A and PWM induced strong proliferative responses, while PHA and LPS induced comparatively low proliferative responses. Responses of mitogen stimulated PBMC to recombinant human interleukin-2 (rhIL-2) and in vitro immunoglobulin production by mitogen stimulated PBMC were measured to discriminate between stimulation of T cells and B cells. It was found that Con A and PHA stimulate phocine T cells, PWM stimulates both T cells and B cells and LPS predominantly stimulates phocine B cells. Antigen-specific immune responses were measured after immunization of seals with an inactivated rabies vaccine and/or with tetanus toxoid. Antigen-specific proliferation of PBMC and the presence of antigen-specific antibody forming cells were demonstrated for both antigens in the PBMC of immunized animals. The responses measured in vitro correlated well with the development of specific serum antibody titers to these antigens.

Enhanced triggering of mucosal immune responses by reducing splenic phagocytic functions

The role of the spleen in the rat mucosal immune response was investigated to three structural different pneumococcal polysaccharides, type 3, 4, and 14. Following immunization with pneumococcal polysaccharides, a larger amount of free antigen was found in several lymphoid tissues and an increased trapping of immune complexes was seen in follicles of splenectomized animals, as compared to control animals. Thus, clearance of the polysaccharides seems to be less effective after splenectomy. An increase in specific IgA antibody-containing cells (ACC) was found in mesenteric lymph nodes, villi and Peyer's patches in splenectomized rats. Apparently, splenectomy and subsequent decreased clearance of the antigen causes a prolonged stay of the antigen in the system and therefore specific ACC can be induced in different lymphoid tissues. After splenectomy the specific IgM and IgG antibody titers in serum decreased significantly for pneumococcal polysaccharides types 4 and 14, but not for type 3. Furthermore, the serum IgA antibody titers against the three types of polysaccharides under study were not affected. After elimination of macrophages in the spleen by treatment with dichloromethylene diphosphonate liposomes no ACC against type 14 were evoked in the marginal zone of the spleen, and again, an increase was observed in specific IgA ACC in mucosa-associated lymphoid tissues. The IgA antibody titers were also enhanced. In conclusion, IgA responses against pneumococcal polysaccharides can be elicited in absence of the spleen, i.e. at mucosal sites or in the draining lymph nodes. Furthermore, polysaccharide-specific IgA responses are enhanced after reduction of splenic phagocytic functions.

Immunological Reconstitution in Severe Combined Immunodeficiency after Bone Marrow Transplantation from HLA-matched Sibling

A boy with severe combined immunodeficiency received bone marrow transplantation from an HLA-compatible sibling, and immunological reconstitution was achieved. He had hypogammaglobulinemia, decrease in T cell number, inbalance of T cell subsets, and defective lymphocyte blastoid transformation. At age of 14 months, bone marrow cells from his sister were infused intravenously. Eleven days after the transplantation, positive mitogenic responses to PHA and Con A were first demonstrated. However, acute graft-versus-host disease was observed at 2 weeks, but it was mild and lasted for a few weeks. Two months later, serum IgG and IgM increased rapidly up to the levels of 888 mg/dl and 268 mg/dl, respectively, accompanied by the elevation of specific serum antibody titers, and the number of T cells and T cell subsets were normalized. Positive delayed-type cutaneous hypersensitivities to some specific antigens were also demonstrated. Lymphocyte chimerism after marrow transplantation was shown by analysis of sex-chromosome. He has been well, for the last 21 months without any treatment.

Effects of Vaccination with SolcoTrichovac on the Vaginal Flora and the Morphology of the Doederlein Bacilli

The effects of SolcoTrichovac vaccine on the vaginal flora and the vaginal pH were studied in 19 patients with trichomoniasis and in 46 patients with bacterial or candidal vaginitis. Treatment with SolcoTrichovac resulted in the disappearance of the parasites and a cure in 18 of the 19 cases of trichomoniasis (95%) and in all the 46 cases of vaginitis of other aetiologies. In both groups there was a highly significant increase in the lactobacilli of the normal Doederlein flora, and in both groups the initially raised intravaginal pH levels of about pH 6 dropped highly significantly (p < 0.001) to levels of about pH 5. All the patients responded to the vaccination. Their specific serum antibody titres showed a 16-fold increase from the basal levels within 3 months after the third vaccine injection.

A Study of Optimum Dose Immunotherapy in Pharmacological Treatment Failures

Forty-six patients with allergic rhinitis who were refractory to antihistamine/decongestant drugs were entered into a study to evaluate the effectiveness of optimal dose immunotherapy. Of the patients described, 91% reported symptomatic improvement within 24 weeks. Total IgE was seen to decrease in 76% of the patients in the same time frame. Nasal eosinophilia and specific IgE antibodies also were seen to decrease substantially. The results of this study indicate that immunotherapy, based on the patient's sensitivity as measured by specific serum antibody titers and titrated skin end points, is effective in alleviating symptoms and altering abnormal immunological factors.

CLINICAL EVALUATION OF 1‐β‐D‐RIBOFURANOSYL‐1,2,4‐TRIAZOLE‐3‐CARBOXAMIDE (RIBAVIRIN) IN A DOUBLE‐BLIND STUDY DURING AN OUTBREAK OF INFLUENZA

1-beta-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin) at a dosage of 300 mg/day, or disguised placebo was administered to patients in a closed population during an epidemic outbreak of influenza in Mexico City. Treatment consisted of capsules given three times daily for 5 days beginning with first signs of disease. The study was conducted in a double-blind fashion. Clinical manifestations of the disease, as well as in titer of recoverable virus and in specific serum antibody titer were significantly reduced in the ribavirin-treated group. None of the individuals in the study had any sign of toxic effects attributable to the drug. In the study, 21 patients received the drug and 24 received placebo.

STUDIES OF THE SUDDEN INFANT DEATH SYNDROME IN KING COUNTY, WASHINGTON: IV. IMMUNOLOGIC STUDIES

Prospective and retrospective studies of immunologic responses in the sudden infant death syndrome (SIDS) revealed the following: The concentrations of IgM in cord or death bloods from patients with SIDS did not differ significantly from values found in cord blood from healthy infants or death blood from infants dying of explained causes. Similarly, IgE in death blood of patients was not elevated as compared to controls nor was the third component of complement depressed. Specific antibody titers in cord or death serum to 14 common viral antigens did not reveal any aberrant characteristics in the SIDS infants. Other immunological parameters investigated included antinuclear factor and antiantibodies, also with negative results, indicating that immunological mechanisms may not be of primary significance in the pathogenesis of SIDS. Although this study represents generally negative findings, it is our hope that it will be a useful guide to other interested workers who are planning projects related to this problem.

Foot-and-Mouth Disease in wildlife in Rhodesia and other African territories: A serological survey

The results of neutralisation tests of 1,323 sera collected in a random survey over a five-year period from African wildlife against types of Foot-and-Mouth Disease virus are presented. Significant specific serum antibody titres were demonstrated in sixteen, all cloven hoofed, of the 39 species tested.