An immunogenetically defined and immunodominant Trypanosoma cruzi antigen.

Two strains of mice, A. SW (H-2s) and A.CA (H-2f), were immunized with live trypomastigotes or epimastigotes of the Tulahuen strain of Trypanosoma cruzi or with their sonicates.

Non-lytic antibodies in H-2-controlled resistance to acute infection with Trypanosoma cruzi.

1. Resistance to acute Trypanosoma cruzi infection in mice is a polygenic character with a major factor linked to the murine major histocompatibility system (H-2). We found that F1 hybrids A.

New H-2-linked cell and serum antigens.

A system of two public serum antigens, alpha and delta, whose distribution in inbred strains of mice is different from that of all serum antigens known, is described. Their distribution in the H-2 congenic and in the recombinant inbred HTG strain indicates that they are determined by a gene(s) tightly linked to H-2. Backcross tests confirmed this; only 1.

Immune response to glutaraldehyde-treated cells. I. Dissociation of immunological memory and antibody production.

Glutaraldehyde (GA)-treated sheep red blood cells (SRBC) or H-2-allogeneic spleen cells (SC), induced immunological memory with absent or markedly reduced primary antibody production. In contrast, a normal secondary response was obtained when GA-SRBC or GA-SC were given to mice primed with the corresponding untreated antigens. The secondary response of mice primed and boosted with GA-treated cells was relatively high with GA-SRBC, and negative or very low with GA-SC.

Murine complement component 3: genetic variation and linkage to H-2.

Two electrophoretic variants of murine complement component 3 (C3) were detected by using high-voltage electrophoresis of fresh mouse serum in agarose gels. Most of the inbred strains tested were homozygous for the S allele (for the slow-migrating variant); only four out of 46 strains had the alternative F allele (fast variant). Pen-bred Swiss-Webster animals belonged to one of three phenotypes--S, F, or SF--and the genes responsible for this variation segregated in a strictly Mendelian manner.

Effects of cortisone on H-2 agglutinin response in normal and thymectomized adult mice.

Cortisone suppresses circulating -2 agglutinins when given prior to the injection of soluble cell extracts but not when the same antigens are given as cells. This same difference in antigen handling is observed in adult cortisone-treated thymectomized mice. Thus thymus as such is not involved in these differences in antigen handling.

Lack of correlation between the effects of cortisone on mouse spleen plaque-forming cells and circulating anti-sheep red blood cell haemolysins.

The effect of 5.5 mg of cortisone acetate given to adult mice 1 day prior to the injection of 4 × 10 sheep erythrocytes was studied. This drug is able to suppress more than 95 per cent of splenic plaque-forming cells (PFC) compared with immunized animals not treated with cortisone.