T(h)1 versus T(h)2 cytokine profile determines the modulation of in vitro T cell-independent type 2 responses by IL-4

Asthma status and waning of measles antibody concentrations after measles immunization

BACKGROUND

Asthmatics have increased risks of common and serious microbial infections including vaccine preventable diseases. Little is known about whether asthma influences waning of humoral immunity. We assessed whether asthma status influences waning of anti-measles virus antibody concentrations over time.

METHODS

The study used a cross-sectional study cohort of healthy children who had been immunized with 1 dose of MMR-II at age approximately 15 months. Between 5 and 12 years of age, measles vaccine virus-specific antibody (IgG) values were measured by enzyme immunoassay and considered seropositive if the enzyme immunoassay index unit was ≥ 1. The medical records were reviewed to determine asthma status during the first 18 years of life by applying predetermined criteria for asthma. A least squares regression model was used to evaluate the effect of asthma status on the relationship between measles antibody titer and time elapsed between the initial measles vaccination and measurement of measles antibody concentrations.

RESULTS

Of the 838 eligible children, 281 (34%) met criteria for asthma. Measles antibody waned over time (r = -0.19, P < 0.001), specifically more rapidly in asthmatics (r = -0.30, P < 0.001, a decrease of -0.114 unit per year) than non-asthmatics (r = -0.13, P = 0.002, a decrease of -0.046 unit per year; P value for interaction = 0.010). This differential waning rate resulted in a lower mean (SD) measles antibody concentration [1.42 (0.67) vs. 1.67 (0.69), P = 0.008] and lower seropositivity rate (73% vs. 84%, P = 0.038) in asthmatics than non-asthmatics starting around 9.3 years after the initial measles vaccination.

CONCLUSION

Asthma status is associated with waning kinetics of measles antibody among children.

Risks for infection in patients with asthma (or other atopic conditions): is asthma more than a chronic airway disease?

Most of the research effort regarding asthma has been devoted to its causes, therapy, and prognosis. There is also evidence that the presence of asthma can influence patients' susceptibility to infections, yet research in this aspect of asthma has been limited. There is additional debate in this field, with current literature tending to view the increased risk of infection among atopic patients as caused by opportunistic infections secondary to airway inflammation, especially in patients with severe atopic diseases. However, other evidence suggests that such risk and its underlying immune dysfunction might be a phenotypic or clinical feature of atopic conditions. This review argues (1) that improved understanding of the effects of asthma or other atopic conditions on the risk of microbial infections will bring important and new perspectives to clinical practice, research, and public health concerning atopic conditions and (2) that research efforts into the causes and effects of asthma must be juxtaposed because they are likely to guide each other.

What does tympanostomy tube placement in children teach us about the association between atopic conditions and otitis media?

Otitis media is the most common infection second only to viral upper respiratory infection in the outpatient setting. Tympanostomy tube insertion (TTI) is the most common ambulatory surgical procedure in the USA. While many risk factors for otitis media have been identified, atopic conditions have been underrecognized as risk factors for recurrent and persistent otitis media. Given that asthma and other atopic conditions are the most common chronic conditions during childhood, it is worth examining the association between atopic conditions and risk of otitis media, which can provide insight into how atopic conditions influence the risk of microbial infections. This paper focuses its discussion on otitis media; however, it is important that the association between atopic conditions and risk of otitis media be interpreted in the context of the association of atopic conditions with increased risks of various microbial infections.

Impact of genetic variants in IL-4, IL-4 RA and IL-13 on the anti-pneumococcal antibody response

BACKGROUND

Significant differences in immune responses upon vaccination have been described, suggesting genetics are important in determining the magnitude of vaccine responses. The interleukin (IL)-4 pathway, including IL-4, IL-13 and the IL-4 receptor alpha chain (IL-4 Ralpha), is central to humoral responses and therefore could have an impact on vaccine responsiveness.

OBJECTIVE

To investigate whether single nucleotide polymorphisms (SNPs) in the IL-4, IL-13 and IL-4 RA genes influence pneumococcal serotype-specific IgG antibody responses.

METHODS

SNPs in the IL-4 gene (C -589T, G2979T), the IL-13 gene (G -1112A, Arg130Gln) and in the IL-4 RA gene (Ile50Val, Gln551Arg) were investigated in isolation and in combination, for their influence on serotype-specific IgG antibody responses upon combined pneumococcal conjugate and polysaccharide vaccinations in children with a history of recurrent otitis media.

RESULTS

Lower antibody responses were observed for alleles previously associated with atopy, IL-4 -589T, IL-4 2979T and IL-4 Ralpha 551Gln. Effects were stronger in gene haplotype combinations or in multiple haplotype combination analyses.

CONCLUSION

This study highlights the importance of host genetic factors in vaccine responses. Furthermore, it supports the approach of studying the effect of combinations of multiple alleles, in haplotypes or in combinations of haplotypes, on complex phenotypes within a biological pathway.

Properties of hybridomas generated by spleen cells of IL-4- and IL-13-knockout mice

Interleukin-4 (IL-4)- and IL-13-knockout mice were immunized with murine recombinant IL-4 or IL-13, and spleen cells were fused with P3X63-Ag8.653 myeloma cells. Selection of the antigen-positive hybridomas was fulfilled in the presence of IL-6 containing thymic stroma cell supernatant (TSS). All of the selected anti- IL-4- and anti-IL-13-specific hybridoma clones (eight and 10, respectively) required the presence of TSS (0.5-2.5%) for their cloning, stable growth in large-scale cultures, and production of monoclonal antibodies (MAbs). Several of the anti-IL-4-specific clones were adapted to growth without TSS. However, the loss of antibody-secreting capacity in the process of adaptation to TSS-free growth was detected. The data demonstrate that cytokine-deficient mice technology can be used for generation of MAbs to autologous cytokines.

Cytokine-deficient mice as a model for generation of autologous anti-cytokine monoclonal antibodies

The possibility of inducing immune responses to murine interleukin-4 (IL-4) and IL-13 and generating anti-cytokine monoclonal antibodies (mAbs) was studied in IL-4- and IL-13-knockout mice. The minimal doses of IL-4 or IL-13 that could induce significant anti-cytokine responses with titers of 5000-10,000 were 20 microg per injection with the total doses of 100 microg. The highest titers in a range of 20,480-40,960 were achieved by triple immunization of IL-13-knockout mice with 30 microg of IL-13 per injection. Anti-IL-4 mAbs were generated at an antibody serum titer about 400; however, only 0.5% of primary hybridoma clones were anti-IL-4-positive. Anti-IL-13 cell fusions were successful at titers of 20,480 and 40,960 with 50% of the primary clones positive. Both hybridomas secreted low-affinity IgMkappa mAbs and were IL-6-dependent. These data demonstrate that IL-4- and IL-13-deficient mice may develop high polyclonal immune responses to "syngeneic" murine cytokines but fail to generate high-affinity mAbs at the tested conditions.