Jirayr R. Roubinian

Androgenic Hormones Modulate Autoantibody Responses and Improve Survival in Murine Lupus

Antibodies to native DNA and to polyadenylic acid (Poly A) occur spontaneously and undergo a regulated switch from IgM to IgG during the course of autoimmune disease in NZB/NZW F(1) (B/W) mice. B/W females have higher titers and earlier commitment to 7S antibodies to DNA and Poly A, whereas B/W males bind DNA and Poly A primarily by 19S antibodies. We have performed castration experiments to determine the effects of sex hormones on this switch from IgM to IgG.NZB/NZW F(1) (B/W) mice were either castrated or subjected to sham surgery at 2 wk of age and studied for immunoglobulin class of antibodies to nucleic acids at 4, 6, and 7 mo post-surgery. Prepubertal castration of males caused premature death in 60% of mice. Castrated males had a significant decline in their serum testosterone concentration, an increase in DNA and Poly A binding, and an accelerated switch from 19S to 7S antibodies to nucleic acids. Castrated females had no change in mortality. However, castrated females given maintained androgen treatment had a decreased mortality compared to castrated females receiving estrogen (14 vs. 94%). The anticipated switch to 7S antibodies to Poly A was almost eliminated in castrated females. These results suggest that sex hormones modulate immunologic regulation and that androgenic hormones are protective in murine lupus.

Delayed Androgen Treatment Prolongs Survival in Murine Lupus

Female NZB/NZW F1 mice were treated as adults with 5-alpha-dihydrotestosterone powder packed into subcutaneous implants. Two treatment protocols were followed: (a) 3-mo-old mice received 6 mg of androgen, and (b) 6-mo-old mice were castrated and given 12 mg of androgen. Sham females received empty implants. Mice were followed monthly for surival, for antibodies to DNA and polyadenylic acid, and for renal histopathology. The percent survival at 11 mo was 74% for mice treated at 3 mo, compared to 11% for the sham controls, and 100% for mice treated at 6 mo, compared to 20% for their sham controls. Androgen-treated mice had less immune complex glomerulonephritis as determined by immunofluorescent and electron microscopy. Surprisingly, treated mice had no significant sustained reduction in antibodies to DNA although they had reduced antibodies to polyadenylic acid. These results suggest that androgens can still prolong survival and reduce immune complex deposition even when treatment is delayed to an age when disease is relatively established. After delayed androgen treatment, mice survive despite the presence of high levels of IgG antibodies to DNA.

Sex steroids and the immune system-I. Sex difference in autoimmune disease in NZB/NZW hybrid mice

Abstract Hybrid NZB/NZW (B/W) mice develop an autoimmune disease that has many of the characteristics of human systemic lupus erythematosis including marked sex differences. Studies were done to investigate the role of gonadal steroids in modulating expression of disease. Estrogens accelerate and androgens slow the time course of appearance of antibodies to nucleic acids and death when administered by implants. Castration of females does not influence survival whereas castrated males have earlier development of antibodies and accelerated mortality similar to intact females. In general, administration of estradiol or progesterone accelerates the appearance of IgG antibodies to both DNA and Poly A whereas dihydrotestosterone or testosterone retarded antibody formation. Surprisingly, coadministration of estradiol and dihydrotestosterone increased the mortality rate in both sexes. Studies with estradiol demonstrated receptor-like binding in cytosol and nuclear extracts prepared from the thymus of several strains of mice whereas DHT binding could not be found. Administration of estradiol elevated total receptor binding in the thymus of male B/W mice. While complex mechanisms with other systems are involved, it appears that the sex steroids can influence antibody formation by interaction with the thymus gland.

Quantitative immunofluorescence microscopy of renal glomeruli from mice exhibiting murine lupus erythematosus

Pathologic changes in renal glomeruli of mice with systemic murine lupus erythematosus were quantified using microfluorophotometry. Cryostat sections were taken from kidneys of affected mice, stained with fluorescein-conjugated anti-mouse immunoglobulin, and the extent of immune complex glomerulonephritis was determined. A subjective microscopic examination procedure, which has been used previously, was compared with quantitative microfluorophotometry and a close correlation between the results using each of the two methods was found. Since the microfluorometric procedure measures the total fluorescence per glomerulus, subjective microscopy must estimate that same quantity in a linear fashion. The present advance in measuring capability indicates good potential for rapid, quantitative measurements for further studies on systemic lupus erythematosus, and on other tissue sections stained with fluorescent antibodies.