Immune responses to hapten conjugatesin vitro

Several functions of the animal body can take place in cell or tissue cultures with almost unreduced efficiency and precision. Functions, where only one cell type is involved, often do so, but also some differentiation steps where interactions between two or more cell types are clearly needed can take place in tissue culture (Saxénet al.1968). Most immune responses require collaboration between two or more cell types (Claman, Chaperon & Triplett, 1966; Miller & Mitchell, 1968; Feldmann & Nossal 1972c). Some of them can be easily inducedin vitrobut others cannot. Even when antibody responses can be inducedin vitrotheir intensity varies a great deal. With some antigens and under some circumstances a responsein vitrocan be nearly as strong as onein vivo.A crude comparison can be derived from responsesin vitroandin vivoto the same antigen, conjugate of hapten NIP and pneumococcal polysaccharide type III (NIP-SIll, Nakamura, Ray & Mäkelä, 1973).