In vivo effects of monoclonal antibody against ICAM-1 and LFA-1 on antigen-induced nasal symptoms and eosinophilia in sensitized rats

We applied anti-ICAM-1 and anti-LFA-1 monoclonal antibody (mAb) to ovalbumin-sensitized rats and examined the effects on nasal eosinophilia and nasal symptoms following topical antigen challenge. In a general and local immunization (GLI) group of rats, the mAbs were applied during the booster topical immunization period. In a general immunization group and a local immunization (LI) group of rats, the mAbs were applied during the immunization period. The number of sneezes and nasal scratching movements occurring soon after topical antigen (Ag) challenge was significantly suppressed in the GLI and LI group rats. Eosinophil infiltration into nasal mucosa 24 h after Ag challenge was also significantly suppressed in GLI and LI group rats. These findings suggest that the ICAM-1/LFA-1 system is important in topical allergic inflammation in rats.

Vaccination with herpes simplex virus type 1 glycoprotein K impairs clearance of virus from the trigeminal ganglia resulting in chronic infection

Following primary ocular infection, HSV-1 establishes a latent infection in the trigeminal ganglia with the complete absence of detectable infectious virus. Recently, we showed that vaccination of BALB/cJ with HSV-1 glycoprotein K (gK), but not other HSV-1 glycoproteins, significantly exacerbated the severity of HSV-1-induced ocular disease and herpetic dermatitis (H. Ghiasi et al. J. Virol. 68, 2347-2354, 1994). We now report that prior vaccination with gK blocked viral clearance from trigeminal ganglia until at least Day 56 postinfection, resulting in a chronic infection. The significance of this novel finding with respect to potential harmful complications associated with the immune response to gK is discussed.

Sensitization and reactogenicity of two doses of candidate antileprosy vaccine Mycobacterium w

M.w vaccine is one of the antileprosy vaccines under test in an ongoing comparative vaccine trial in South India. The objective of the present study was to examine the sensitizing ability, as measured by skin test reactions to Rees' MLSA and lepromin, and reactogenicity of M.w vaccine in the local population. Two doses of M.w, 1 x 10(9) bacilli and 5 x 10(9) bacilli, were used, in two separate studies of 395 and 400 "healthy" individuals aged 1-65 years. In each study, the study subjects received either M.w vaccine or normal saline (control), by random allocation. The results showed that healing of vaccination lesions was uneventful although the healing process was somewhat prolonged with the higher dose. The mean size of lesions was 7.0 mm and 9.5 mm with the low and high doses of the vaccine, respectively. The results also showed that M.w vaccine in a dose of 1 x 10(9) bacilli, failed to induce post-vaccination sensitization as measured by reactions to Rees' MLSA and by Fernandez and Mitsuda reactions to lepromin-A. However, when the dose of the vaccine was increased to 5 x 10(9) bacilli the mean sizes of post-vaccination reactions to Rees' MLSA and lepromin-A (both early and late) were significantly larger in the vaccine group compared to that in the control group. The sensitizing effect attributable to the vaccine was of the order of 1.5 mm to 1.8 mm.

Characterization of the protective borreliacidal antibody response in humans and hamsters after vaccination with a Borrelia burgdorferi outer surface protein A vaccine

Significant borreliacidal antibody was induced in volunteers and hamsters 60 days after primary and secondary vaccination with high concentrations of recombinant outer surface protein A (rOspA). However, the borreliacidal antibody response waned rapidly. Only 1 person had detectable cidal activity 180 days after vaccination. Similarly, the borreliacidal antibody response waned rapidly in hamsters by week 10 of vaccination. By contrast, the total anti-rOspA antibody response remained elevated in volunteers and hamsters. When isolates of Borrelia burgdorferi sensu lato were incubated in sera from vaccinated humans or hamsters, only the vaccine-specific isolate was killed. These results were confirmed by challenging rOspA-vaccinated hamsters with different isolates of B. burgdorferi sensu lato. The results showed that monitoring total rOspA antibody is inappropriate for evaluating the efficacy of an rOspA vaccine. The rOspA vaccine must be improved to yield comprehensive protection and maintain sustained levels of protective borreliacidal antibodies.

Risk factor for neonatal tetanus in west Burkina Faso: a case control study

A case-control study was carried out to identify risk factors for neonatal tetanus in rural Burkina Faso. Each of the 31 cases identified prospectively were matched with two controls. Risk factors such as the instrument used to cut the umbilical cord and the qualification of the midwives were only identified in the univariate analysis. The multifactorial analysis identified factors commonly believed to be associated with neonatal tetanus: lack of mother's immunization and place of birth other than maternity clinics. However, applying karite nut butter on the umbilical cord was found to be a strong independent factor associated with neonatal tetanus. Immunization of mothers against tetanus should be enforced. Health education must take into consideration sociocultural realities of these populations.

Common (but not always considered) viral infections of the lower respiratory tract

Viral lower respiratory tract infections continue to cause a great deal of morbidity and mortality in the United States and worldwide, despite advances in treatment options, chemoprophylaxis, and vaccine development. The availability of ribavirin has improved the outlook in high-risk patients who develop respiratory syncytial virus bronchiolitis while intensive efforts are continued to develop an efficacious and safe vaccine. Respiratory syncytial virus immunoglobulin may prove to be a useful tool in the armamentarium of the pediatrician to prevent or modify respiratory syncytial virus disease in individual patients. Influenza vaccination and chemoprophylaxis remain mainstays in the prevention of influenza disease in high-risk individuals. The availability of a vaccine for varicella and a wider dissemination of measles vaccine, particularly in developing nations, may well limit the adverse outcomes associated with pneumonias caused by these two viruses. The transplant patient and other immunocompromised patients will continue to challenge clinicians and scientists to provide innovative and effective therapies for viral infections. The exciting advances in clinical and research virology over the last decade offer much hope to practicing pediatricians who struggle with offering prevention strategies and treatment options for their patients. Viral lower respiratory tract infections will never be eliminated as a clinical problem, although the morbidity and mortality associated with them will continue to improve.

Cytokines and tumor vaccination

Patients with locally advanced stages of renal cell carcinoma are at high risk of relapse or progress even after initial radical surgery. Based on the proven efficacy of adoptive and active immunotherapeutic approaches of metastatic renal cell carcinoma, a phase II trial was started in 1989 using autologous, Newcastle disease virus modified and lethally irradiated tumor cell vaccines in combination with low-dose recombinant interleukin-2 (1.8 million U) and recombinant interferon-alpha 2a (1.0 million U) for a surgical adjuvant treatment. Patients were vaccinated (subcutaneous injection) once a week for 8-10 weeks and the treatment was started about 4-10 weeks after surgery. Up to now more than 208 patients with locally advanced renal cell carcinoma (stages pT2-3a, N1-2, M0; pT3b-4, N0-2, M0) were vaccinated after initial radical surgery (tumor nephrectomy with lymph node dissection and ipsilateral adrenalectomy and if necessary in combination with en bloc removal of venous extensions). We overview a follow-up of 203 evaluable patients with a median disease-free survival of 21 months (range of 2-64 months). During this observation period 18 relapses (8.9%) were diagnosed with 3 local relapses (1.5%), 10 lymph node metastases (5%) and/or distant organ metastases in 9 cases (4.5%). These progressive patients' disease was treated by surgery and/or combined immunochemotherapy. Toxicity encountered on this tumor cell vaccination was mild (WHO grade 1) and was characterized by flu-like symptoms and fever up to 38.8 degree Celsius for some hours beginning at 4 hours after the vaccine/cytokine application. Occasionally a transient local inflammation at the site of injection was observed. The comparison of the risk-factor-adapted group of adjuvant treated renal cell carcinoma patients (locally advanced stages) with historical data gave evidence for an improvement in disease-free survival on vaccination treatment. Although this was not a prospective randomized trial, we can summarize that the surgical adjuvant treatment of autologous tumor vaccines in combination with low-dose cytokines may improve relapse-free and overall survival in patients with locally advanced renal cell cancer.

Killing of Toxoplasma gondii oocysts by irradiation and protective immunity induced by vaccination with irradiated oocysts

Toxoplasma gondii oocysts are highly resistant to environmental influences. To study the effect of alpha-irradiation on the viability of T. gondii oocysts, 1 million sporulated oocysts of the VEG strain were irradiated to absorbed doses of 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, or 0.50 kGy at 5 C with a 137Cs gamma-irradiation source. Treated oocysts were bioassayed for viable T. gondii in mice. Viable T. gondii was not found in brains of mice 2 mo after oral inoculation with oocysts irradiated at levels > or = 0.25 kGy. Therefore, alpha-irradiation is an effective means of killing T. gondii oocysts. Mice inoculated orally with oocysts irradiated at 0.20 and 0.40 kGy were partially protected when challenged orally with lethal doses of nonirradiated oocysts.

Resistance to tick-borne spirochete challenge induced by Borrelia burgdorferi strains that differ in expression of outer surface proteins

Hamsters were immunized with thimerosal-killed Borrelia burgdorferi 297 or a mutant of 297 (M297) that lacks the 49-kb linear plasmid and expression of outer surface proteins A and B (OspA and OspB). Ixodes scapularis nymphs infected with either the B. burgdorferi sensu stricto strain 297 or JMNT, similar in OspA and OspB but differing in OspC expression, were used to evaluate protection. In a homologous challenge, 24 hamsters were vaccinated, 8 each with 297 or M297 and 8 sham (adjuvant)-vaccinated controls. Hamsters vaccinated with either bacterin were completely protected against a natural tick bite or subcutaneous (s.c.) inoculation of 297. Borreliae were effectively eliminated from 80 to 90% of the 297-infected ticks that fed on four hamsters immunized with the 297 bacterin. Cultures of spirochetes isolated from the ticks that remained infected were infectious and induced joint inflammation in naive hamsters. There was no reduction of strain 297 spirochetes in ticks that fed on four hamsters immunized with M297, but the hamsters were protected. Results with the M297 bacterin indicate that proteins other than OspA or OspB can protect hamsters against a tick challenge without eliminating B. burgdorferi in the tick. In a heterologous challenge, 36 hamsters were vaccinated, 12 with each bacterin and 12 controls. None of the hamsters immunized with either bacterin were protected from a challenge involving JMNT-infected ticks, while two of four were protected against an s.c. challenge. Hamsters challenged s.c. with strain 297 spirochetes were protected. There was partial elimination of JMNT spirochetes in ticks that fed on the group of four hamsters immunized with the 297 bacterin, and infection rates were reduced by 50 to 60%. JMNT spirochetes reisolated from the ticks that fed on 297-vaccinated hamsters also remained infectious for hamsters. In the JMNT-infected ticks that fed on four M297-immunized hamsters, there was no decline in the proportion of infected ticks. Destruction of spirochetes in ticks that fed on the hamsters vaccinated with the 297 bacterin suggests that antibodies to OspA and OspB may have been responsible, since the mutant did not induce this activity.

The incidence of hepatitis B infection in Australia: an epidemiological review

Hepatitis B virus (HBV) infection in Australia remains a significant problem despite the availability of an inexpensive vaccine. National information about incidence, prevalence, morbidity and the extent of vaccine coverage is incomplete; improved surveillance would allow for better targeting and evaluation of prevention activities. Our estimates indicate that 75%-90% of cases of vertical transmission of HBV are preventable through vaccination of newborns whose mothers are carriers.

An alpha-chain TCR CDR3 peptide can enhance EAE induced by myelin basic protein or proteolipid protein

Regulation of experimental autoimmune encephalomyelitis (EAE) can be induced by anti-idiotype immunity against T cell receptor (TCR) fragments associated with major histocompatibility complex (MHC) molecules. However, we have recently found that preimmunization with an alpha-chain TCR CDR3 peptide (LYFCAARSNYQL) derived from myelin basic protein (MBP)-specific clones did not suppress but rather augmented the severity of EAE induced by MBP-specific T cells in SJL/J mice. To test whether CDR3 vaccination could control only a highly restricted T cell population, we studied the effect of the peptide against EAE induced by T cells specific for different Ag/MHC ligands and autoimmune diseases affecting non-neural tissues. In contrast to expectations, the peptide was found to augment not only EAE induced by MBP-specific T cells, but also proteolipid protein (PLP)-specific T cell- or PLP peptide-induced EAE in SJL/J mice, and MBP-induced EAE and adjuvant arthritis (AA) in rats. The CDR3 peptide was neither inhibitory nor supportive for Ag-induced activation of an encephalitogenic clone in vitro. In addition, the peptide treatment neither inhibited the induction of Ag-specific T cells nor altered the APC function of spleen cells. These findings, on the one hand, confirm previous results showing TCR peptide-induced enhancement of the disease and, on the other hand, indicate that the TCR CDR3 peptide may control T cells with broader Ag/MHC specificities than could be expected. Structural similarity among TCR idiotypes of autoimmune T cells may partly account for these results.

The immunogenic and pathogenic potential of short poly(C) tract Mengo viruses

We have shown previously that genetically engineered Mengo viruses with artificial deletions in their 5' noncoding polyribocytidylic acid (poly(C)) tracts are highly attenuated for the natural murine host and also for other animals such as baboons, macaques, and domestic pigs. The present report further characterizes select short poly(C) tract Mengo viruses in the natural murine host. A positive correlation was found between the length of the poly(C) tract and murine virulence, as measured by virus brain titers and brain lesion scores after infection. Histological examination of brain tissue collected from infected animals clearly showed that the short poly(C) tract viruses did not induce the devastating pathological effects characteristic of animals inoculated with wild-type virus. Instead, the short-tract Mengo viruses proved excellent immunological agents. A dose of only 100 plaque-forming units of vMC24 (poly(C) tract: C13UC10), injected subcutaneously, protected 80% of recipient animals against a normally lethal dose of encephalomyocarditis virus. The protection was long-lived, and animals similarly immunized with vMCo virus (poly(C) tract: Co) still had protective neutralizing antibody titers up to 16 months after inoculation. In addition, the short-tract viruses proved genetically stable, in that the vMC24 virus did not yield detectable pathogenic revertants even after multiple, forced passages in 4-week-old mice. These studies suggest that Mengo viruses containing deletions in their poly(C) tracts are biologically safe and potent immunogens and imply that they may have uses as cardiovirus vaccines.

Deletion of CD4+ T cells by mouse mammary tumor virus (FM) superantigen with broad specificity of T cell receptor beta-chain variable region

We previously identified a superantigen from the exogenous mouse mammary tumor virus carried by FM mice [MMTV (FM)], which can preferentially activate V beta 8.2+ CD4+ T cells by subcutaneous injection. In the present study we investigated the effect of neonatal infection with the virus on the T cell receptor (TCR) beta-chain variable region (V beta) repertoire, T cell immune response, and development of experimental allergic encephalomyelitis (EAE). The infection, surprisingly, resulted in deletion of a large portion of CD4+ T cells including V beta 2+, 6+, 8.1+, 8.3+, and 14+ CD4+ T cells in addition to V beta 8.2+ CD4+ T cells. Nevertheless, the infection marginally affected T cell immune response to various antigens such as ovalbumin (OVA) and alloantigen except the abrogated response to anti-V beta 8.2 antibody-mediated receptor cross-linking. Moreover, the infection exerted a protective effect on the development of EAE in (PL/J x SJL)F1 mice. Thus, MMTV (FM) superantigen has the ability to delete a large portion of CD4+ T cells with broad TCR V beta specificity, including V beta 8.2+ CD4+ T cells, and may have potential as a therapeutic agent against autoimmune diseases.