PubMed Health⌕ Search

Biomedical subjects

H Cosenza

Publications and source records attributed to H Cosenza.

At least 37 records · Page 2Linked to original sources
PubMed1976

Expression of new idiotypes following neonatal idiotypic suppression of a dominant clone.

The anti-PC antibodies of BALB/c origin bear predominantly the idiotype characteristic of the phosphorylcholine (PC)-binding T15 idiotype than sera from adult mice, and, unlike the latter, they also contain detectable amounts of anti-T15 antibodies. By 2 weeks of age the anti-T15 antibodies are no longer detectable while the T15 idiotype has reached adult levels. Injection of neonatal mice with anti-idiotypic antibodies renders them unresponsive to PC until the 15th week of life. Furthermore, this treatment induces a chronic suppression of the T15 idiotype, since on recovery from unresponsiveness, the neonatally suppressed mice produce anti-PC antibodies which are predominantly T15-negative. In contrast, treatment of adult mice with anti-idiotypic antibodies induces only a transient state of unresponsiveness to PC, and the antibodies produced upon recovery bear the T15 idiotype. These findings are discussed in the context of idiotype anti-idiotype interactions and their possible role in immuno-regulation.

Age Factors↗
PubMed1975

Antibody response to phosphorylcholine in vitro. I. Studies on the frequency of precursor cells, average clone size and cellular cooperation.

The anti-phosphorylcholine (PC) antibodies synthesized by BALB/c spleen cells in microcultures upon immunization with heat-killed vaccine of Pneumococci R36A (Pn) are directed exclusively to the PC epitope. These antibodies are of very restricted avidity and 88% of the responding clones express the idiotype characteristic of the TEPC-15 PC-binding myeloma. This idiotypic restriction appears to be due to the absence of clones capable of expressing other idiotypes, rather than to "clonal dominance". The estimated frequency of precursor cells for the PC epitope is 1 X 10(-5) to 2.5 X 10(-5). These precursors give rise to clones with an average size of 9 plaque-forming cells. When the logarithm of the number of negative wells was plotted against the number of spleen cells/well, the fraction of nonresponding cultures decreased exponentially as the number of spleen cells was increased. This indicated that only one cell type was limiting in our assay, presumably a B cell. Furthermore, treatment of spleen cells with AKR anti serum completely abolished the response to sheep red cells without affecting the response to PC. It is concluded that PC is a T cell-independent antigen. Of interest was the finding that PC requires adherent (A) cells and this is a particular characteristic of PC, since most T cell-independent antigens have been found not to require A cells. Reasons for the possible homogeneity of the response to PC are also discussed.

Animals↗
PubMed1974

Neonatal tolerance induced by antibody against antigen-specific receptor.

Specific immunologic unresponsiveness is induced by injecting adult or neonatal mice with antibody against antigen-specific receptor (antireceptor antibody). Suppression in mice treated as adults lasts several weeks, and cells from these suppressed mice respond normally in culture. In contrast, unresponsiveness induced in neonatal mice is long-lasting; cells from these mice do not respond in culture and do not affect the response of normal cells. Evidently, antireceptor antibody reversibly blocks antigen receptors in adult animals, but induces unresponsiveness in neonatal mice by depleting the clone of receptor-bearing cells.

Animals↗
PubMed1973

Specific suppression of immune responses.

The models we have discussed in detail demonstrate specific suppression of immune reactivity produced in normal adult animals by antibody and antigen. The mechanism of homeostasis of suppression in these models depends on continued exposure to antigen and on an active response by the host. The active response may include production of antibody directed against specific receptors as well as antibody directed against antigen. Thus, specific regulation of both antibody and cell mediated immunity to an antigen might be achieved by the use of only the biological agents of the response: antigen, antibody, and possibly antibody to receptors. The general implication is that these same biological agents are responsible for autoregulation of immune reactions occurring in nature. Presumably, these agents may be used to suppress or reverse immune responses for appropriate clinical objectives.

Animals↗
PubMed1972

Specific inhibition of plaque formation to phosphorylcholine by antibody against antibody.

Spleen cells from BALB/c mice immunized with heat-killed rough pneumococci (strain R36A) or spleen cells from normal mice immunized in vitro with the same antigen produce direct hemolytic plaques against sheep erythrocytes coated with pneumococcal C polysaccharide or conjugated with phosphorylcholine. Formation of plaques is specifically inhibited by phosphorylcholine or by antiserum to mouse immunoglobulin A myeloma protein which binds phosphorylcholine. Thus, the myeloma proteins and normal BALB/c antibodies share similar idiotypic determinants. This experimental system is suitable for probing the role of the antigen receptor in the immune response.

Animals↗
PubMed1972

Specific suppression of the antibody response by antibodies to receptors.

Balb/c myeloma proteins, TEPC 15 and MOPC 167, bind phosphorylcholine and precipitate with the C-polysaccharide moiety of pneumococci R36A. Anti-idiotypic antibodies to TEPC 15 myeloma raised in A/He mice prevent plaque formation by cells releasing antibody to phosphorylcholine and inhibit induction of the antibody response to phosphorylcholine in vitro and in vivo. This suppression is specific since antibodies against non-crossreacting idiotypic determinants of MOPC 167 do not prevent either formation of plaques or induction of the antibody response. Furthermore, the response to sheep erythrocytes is not suppressed by antibodies to TEPC 15. These results indicate that antibodies to phosphorylcholine and cell receptors for phosphorylcholine share similar antigen-binding sites with TEPC 15 myeloma protein. Thus, anti-idiotypic antibodies directed against TEPC 15 myeloma protein function as "anti-receptor" antibodies since they specifically prevent induction of the primary response to phosphorylcholine. It is proposed that antibodies to receptors may be involved in the homeostasis of the immune response.

Animals↗
PubMedDate not supplied

Human immunodeficiency virus infection and syphilis in Hondurian female prostitutes.

The seroprevalence of human immunodeficiency virus (HIV) infection and syphilis was investigated in 181 female prostitutes in Tegucigalpa, Honduras. One particle agglutination test and two enzyme immunoassays, as well as one immunofluorescence test were used for the screening of HIV antibodies. Confirmation of positive results by the screening tests was carried out by Western blot. The prevalence of HIV seropositivity was 4% (8 women). Specific treponemal antibodies were found in 50% (90/181) of the prostitutes as judged by Treponema pallidum haemagglutination assay (TPHA) and/or fluorescent treponemal antibody-absorption (FTA-ABSIgG) test. As estimated by the positivity of any or both non-treponemal tests (VDRL and RPR), a total of 31 (17%) out of the 181 women had active syphilis. A good correlation was found between the results obtained by TPHA and FTA-ABSIgG. IgM antibodies were found in 72% of sera positive by TPHA and/or FTA-ABSIgG. Four out of the 181 women were found to have antibodies to both HIV and Treponema pallidum.

Female↗