Immunoblot analysis of Toxoplasma gondii antigens by human immunoglobulins G, M, and A antibodies at different stages of infection

Abstract

The Toxoplasma gondii antigenic components eliciting the immunoglobulin G (IgG), IgM, and IgA antibody responses were studied by using follow-up sera from a laboratory worker who developed an acute glandular toxoplasmosis after an accidental infection with the protozoa. IgG toxoplasma antibodies reacted with multiple components over a wide molecular weight range from 6,000 to 150,000. In contrast, IgM toxoplasma antibodies reacted predominantly with polypeptides of 6, 25, and 35 kilodaltons, which might be useful in new diagnostic procedures. The general pattern of antigenic components in the IgA toxoplasma antibody response closely resembled that in the IgM response, even though some characteristic features were constantly observed. The possibility that the restricted IgM and IgA antibody responses relate to the pathogenetic events in human toxoplasmosis is considered.

Subcellular localization and quantitative analysis of Toxoplasma gondii target antigens of specific immunoglobulins G, M, A, and E

“…Reactivity was observed with polypeptides of 14, 30, 40, and 50 kDa and major reactivity with 25 and 35 kDa. IgA antibodies gave a pattern closely resembling that given by IgM antibodies: only a few antigenic components of 25,35, and 50 kDa as well as polypeptides of 30,32, and 40 kDa (Partanen et al, 1984). At the ultrastructural level, the present data described different localizations of antigens revealed by IgG antibodies that are in agreement with a wide pattern of immunoreactivity observed by Western blot.…”

“…Another low molecular weight component (6 kDa) reacted only with serum from acutely infected individuals. In contrast to the complex antigenic pattern of IgG Toxoplasma antibodies, a very different pattern with only a few antigenic components was obtained in Western blot with IgM Toxoplasma antibodies from sera of patients with acute toxoplasmosis (Partanen et al, 1984). Reactivity was observed with polypeptides of 14, 30, 40, and 50 kDa and major reactivity with 25 and 35 kDa.…”

“…Western blot analysis (Erlich et al, 1983;Partanen et al, 1984) revealed a complex pattern of immunoreactivity in which most of the antigens over a wide molecular weight ranging from 14 to 150 kDa, with dominating bands from 30 to 67 kDa, reacted with serum IgG from both acutely and chronically infected patients. Another low molecular weight component (6 kDa) reacted only with serum from acutely infected individuals.…”

Anti-P30 IgA antibodies as prenatal markers of congenital toxoplasma infection

“…During the acute phase of toxoplasmosis, we detected IgA antibodies directed against P30 in sera of all patients, sometimes later than specific IgM but always earlier than specific IgG, In the majority of cases, when IgG continued to rise and IgM antibodies persisted ('residual' IgM), IgA antibodies disap- Table 3. Fetuses with anti-P30 IgA antibodies proven to be infected by toxoplasma peared earlier (between 3 and 9 months) and were not detected in the chronic phase of toxoplasmosis, as described in other studies focttsed on the anti-toxoplasma IgA response [4,[8][9][10][11][12][13][14][15][16][17]. We observed only a few exceptions, corresponding to untreated patients, suggesting that the treatment, decreasing the antigenic stimulation, could influence the antibody kinetics.…”

Immune Response to Toxoplasma gondii—Alteration of Antigen Specificity of Peripheral Blood Leukocyte Proliferative Responses in Acute Toxoplasmosis

“…Although visualization of the tachyzoites in blood, lymph nodes, bone marrow, spleen, brain etc., and of the cyst in brain, muscle and other materials is definitively diagnostic, serologic tests for detecting Toxoplasma-specific antibodies are the primary method for diagnosis (5,19). It is generally believed that IgM antibody specific to T. gondii can be observed in the initial stage of T. gondii infection, while the peak titer of IgG antibody is reached within one to two months of the infection (2,17,18) Recently, Partanen et al (15) reported that IgM Toxoplasma antibodies reacted with a limited number of polypeptides of T. gondii antigen, while IgG Toxoplasma antibodies reacted with multiple components over a wide range of molecular weights (from 6,000 to 150,000). Thus, alteration and expansion of B cell clones reactive to T. gondii may be indicated during the clinical course of acute toxoplasmosis.…”