A simple and quick method for enhanced detection of specific IgE in serum from lymphatic filariasis patients

Separation of antigens and antibodies by immunoaffinity chromatography

CONTEXT

Affinity chromatography is an efficient antibody, antigen and protein separation method based on the interaction between specific immobilized ligands and target antibody, antigen, and so on. Populations of available ligands can be used to separate antibodies or their Fab fragments. Similarly, antigens can be isolated by immunoaffinity chromatography (IAC) on immobilized antibodies of low affinity.

OBJECTIVE

This review describes the advantages, the applications, as well as the drawbacks, of IAC in the separation and purification of antibodies and antigens.

METHODS

The present review discussed all types of purification and isolation of antibodies and antigens by IAC, including purification of antibodies using immobilized and synthetic mimic proteins A, G and L; isolation of Fab fragments of antibodies; separation of antibodies against different antigen forms; isolation of antigens by immobilized antibodies and so on. These methods come from over 60 references compiled from all major databases.

RESULTS

Purification of antigens with antibodies should choose low-affinity antibodies to avoid denaturation of most proteins. Concern for cost and safety, prompted research activities focused on novel synthetic ligands with improved properties such as lower cost, avoidance of the risk of contamination associated with natural ligands of human or animal origin to isolate antibodies and antigens.

CONCLUSION

It is anticipated that the improvements of IAC will have impact not only on large-scale production of antibodies but also on the generation of new affinity-based methods for the increasing number of proteins and antibody derivatives available by protein engineering and the proteomics revolution.

The effect of HIV on filarial-specific antibody response before and after treatment with diethylcarbamazine in Wuchereria bancrofti infected individuals

The effect of HIV on filarial-specific antibody response before and after treatment with diethylcarbamazine (DEC) was analysed by comparing two groups of Wuchereria bancrofti-infected adult individuals (positive for circulating filarial antigen) who were positive (n=15) or negative (n=21) for HIV co-infection. Prior to DEC treatment there was no significant difference in filarial-specific IgG1, IgG2, IgG4 and IgE antibody response between the HIV negative and the HIV positive group, while a five times (statistically significant) higher filarial-specific IgG3 response was observed in the HIV positive than in the HIV negative group. At 12 weeks after treatment with DEC, a significant decrease in filarial-specific IgG4 was observed in the HIV positive but not in the HIV negative group, indicating that DEC treatment had a stronger antifilarial effect in individuals co-infected with HIV. DEC treatment had no significant effect on the other classes of filarial specific antibodies, neither in the HIV negative or the HIV positive group.

Immunoepidemiology of Wuchereria bancrofti infection in two East African communities: antibodies to the microfilarial sheath and their role in regulating host microfilaraemia

The response pattern of specific antibodies to the microfilarial sheath (sheath-Ab) of the mosquito-borne filarial parasite Wuchereria bancrofti was investigated in individuals from two East African communities with different levels of endemicity. Individuals from both communities presented a strong inverse relationship between positivity for sheath-Ab and being positive for microfilariae (mf) and circulating filarial antigens (CFA). The prevalence of sheath-Ab positivity was highest in young individuals, but peaked at a younger age in the high (1-14 years) than the low (15-19 years) endemicity community. IgG1, IgG2, IgG3 and IgE intensities to a crude adult filarial worm antigen were higher, and IgG4 intensities were lower, in sheath-Ab positive than in sheath-Ab negative individuals, probably reflecting the infection status of individuals. From the study it appears that individuals become sheath-Ab positive before mf and/or CFA can be detected in the peripheral blood, and only after later disappearance of sheath-Ab from the circulation can CFA and mf be diagnosed. In light of the findings, possible roles of the distinct sheath-Ab in the host-parasite relationship are discussed, and a hypothesis is proposed which suggests that sheath-Ab play an important role in the regulation of host microfilaraemia.